Discontinued Operations and Disposal Groups [Abstract] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Groups, Including Discontinued Operations, Name [Domain] Disposal Group Name [Domain] Discontinued operations [Member] Discontinued Operations [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Huron Legal [Member] Huron Legal [Member] Huron Legal [Member] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Share-based compensation Share-based Compensation Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Significant non-cash investing items of discontinued operations: Noncash Investing and Financing Items [Abstract] Quarterly Financial Information Disclosure [Abstract] Revenues Sales Revenue, Services, Net Reimbursable expenses Reimbursement Revenue Total revenues and reimbursable expenses Revenues Gross profit Gross Profit Operating income Operating Income (Loss) Net income (loss) from continuing operations Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Net income (loss) Net Income (Loss) Attributable to Parent Net earnings per basic share: Earnings Per Share, Basic [Abstract] Net income from continuing operations, per basic share (in USD per share) Income (Loss) from Continuing Operations, Per Basic Share Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share Net income, per basic share (in USD per share) Earnings Per Share, Basic Net earnings per diluted share: Earnings Per Share, Diluted [Abstract] Net income from continuing operations, per diluted share (in USD per share) Income (Loss) from Continuing Operations, Per Diluted Share Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share Net income, per diluted share (in USD per share) Earnings Per Share, Diluted Weighted average shares used in calculating earnings per share: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (shares) Weighted Average Number of Shares Outstanding, Basic Diluted (shares) Weighted Average Number of Shares Outstanding, Diluted Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Computers, related equipment and software [Member] Computers Related Equipment And Software [Member] Computers Related Equipment And Software [Member] Leasehold Improvements [Member] Leasehold Improvements [Member] Furniture and fixtures [Member] Furniture and Fixtures [Member] Assets under Construction [Member] Asset under Construction [Member] Aircraft [Domain] Aircraft [Domain] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Property and equipment Property, Plant and Equipment, Gross Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property and equipment, net Property, Plant and Equipment, Net Income Tax Disclosure [Abstract] Deferred tax assets: Components of Deferred Tax Assets [Abstract] Share-based compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Accrued payroll and other liabilities Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities Deferred Tax Assets, Goodwill and Intangible Assets Deferred Tax Assets, Goodwill and Intangible Assets Deferred lease incentives Deferred Tax Assets Current Deferred Lease Incentive Amount before allocation of valuation allowances of deferred tax assets attributable to deductible temporary differences from deferred lease incentives. Revenue recognition Deferred Tax Assets Revenue Recognition Amount before allocation of valuation allowances of deferred tax assets attributable to deductible temporary differences from revenue recognition. Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Restructuring Charges Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Restructuring Charges Net operating loss carry-forwards Deferred Tax Assets, Operating Loss Carryforwards Tax credits Deferred Tax Assets, Tax Credit Carryforwards Deferred Tax Assets, Other Deferred Tax Assets, Other Total deferred tax assets Deferred Tax Assets, Gross Valuation allowance Deferred Tax Assets, Valuation Allowance Net deferred tax assets Deferred Tax Assets, Net of Valuation Allowance Deferred tax liabilities: Components of Deferred Tax Liabilities [Abstract] Prepaid expenses Deferred Tax Liabilities, Prepaid Expenses Deferred Tax Liabilities, Deferred Expense, Capitalized Research and Development Costs Deferred Tax Liabilities, Deferred Expense, Capitalized Research and Development Costs Property and equipment Deferred Tax Liabilities, Property, Plant and Equipment Intangibles and goodwill Deferred Tax Liabilities, Goodwill and Intangible Assets Deferred Tax Liabilities, Investments Deferred Tax Liabilities, Investments Other Deferred Tax Liabilities, Other Total deferred tax liabilities Deferred Tax Liabilities, Gross Deferred Tax Assets, Net Deferred Tax Assets, Net Document And Entity Information [Abstract] Document and entity information. Entity Registrant Name Entity Registrant Name Trading Symbol Trading Symbol Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Public Float Entity Public Float Accounting Policies [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Retained Earnings [Member] Retained Earnings [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Foreign Currency Transaction Gain (Loss), Realized Foreign Currency Transaction Gain (Loss), Realized Marketing and Advertising Expense Marketing and Advertising Expense New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification Debt Disclosure [Abstract] Interest Expense Recognized [Table] Interest Expense Recognized [Table] Interest Expense Recognized [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Convertible Debt [Member] Convertible Debt [Member] Interest Expense Recognized [Line Items] Interest Expense Recognized [Line Items] [Line Items] for Interest Expense Recognized [Table] Contractual interest coupon Interest Expense, Debt, Excluding Amortization Amortization of debt discount Amortization of Debt Discount (Premium) Amortization of debt issuance costs Amortization of Debt Issuance Costs Total interest expense recognized Interest Expense, Debt Line of Credit Facility [Table] Line of Credit Facility [Table] Convertible Senior Notes [Line Items] Line of Credit Facility [Line Items] Proceeds Debt Instrument, Face Amount Less: debt discount, net of amortization Debt Instrument, Unamortized Discount Debt Issuance Costs, Net Debt Issuance Costs, Net Long-term debt Long-term Debt Equity component Debt Instrument, Convertible, Carrying Amount of Equity Component Postemployment Benefits [Abstract] Employer contributions up to percent of employee's salaries Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay Employer matching contributions Defined Contribution Plan, Employer Discretionary Contribution Amount Deferred compensation liability Deferred Compensation Liability, Current and Noncurrent Derivative Instruments and Hedging Activities Disclosure [Abstract] Fair Value Interest Rate Swaps Designated as Cash Flow Hedging Instruments Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location [Table Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Prepaid Expenses and Other Current Assets [Member] Prepaid Expenses and Other Current Assets [Member] Other Noncurrent Assets [Member] Other Noncurrent Assets [Member] Accrued expenses [Member] Accrued Liabilities [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Fair Value interest rate swaps designated as cash flow hedging instruments Interest Rate Cash Flow Hedge Derivative at Fair Value, Net [Abstract] Fair value (derivative asset and liability) Interest Rate Cash Flow Hedge Derivative at Fair Value, Net Fair Value Disclosures - Promissory Note Reconciliation [Abstract] Fair Value Disclosures - Promissory Note Reconciliation [Abstract] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Receivable Type [Axis] Receivable Type [Axis] Receivable [Domain] Receivable [Domain] Interest Income [Member] Interest Income [Member] Notes Receivable [Member] Notes Receivable [Member] Debt Security [Axis] Debt Security [Axis] Major Types of Debt Securities [Domain] Major Types of Debt Securities [Domain] Promissory Note [Member] Promissory Note [Member] Promissory note. Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring [Member] Fair Value, Measurements, Recurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Assets, Fair Value Disclosure Assets, Fair Value Disclosure Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss) Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss) Income Tax Disclosure [Table] Income Tax Disclosure [Table] Income Tax Disclosure [Table] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves [Domain] Valuation Allowances and Reserves [Domain] Foreign[Member] Foreign Tax Authority [Member] Nature of Uncertainty [Axis] Nature of Uncertainty [Axis] Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Nature of Uncertainty [Domain] Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Nature of Uncertainty [Domain] Effect of Fourth Quarter Event Type [Axis] Effect of Fourth Quarter Event Type [Axis] Effect of Fourth Quarter Events, Type [Domain] Effect of Fourth Quarter Events, Type [Domain] Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] State and Local Jurisdiction [Member] State and Local Jurisdiction [Member] Federal [Member] Domestic Tax Authority [Member] Income Tax Disclosure [Line Items] Income Tax Disclosure [Line Items] Income Tax Disclosure [Line Items] Additional Income Tax Expense or Benefit due to Tax Reform Additional Income Tax Expense or Benefit due to Tax Reform Additional Income Tax Expense or Benefit due to Tax Reform Deferred Tax Assets Revenue Recognition U.S. Income (Loss) from Continuing Operations before Income Taxes, Domestic Effective Income Tax Rate Reconciliation, Percent Effective Income Tax Rate Reconciliation, Percent Current Federal Tax Expense (Benefit) Current Federal Tax Expense (Benefit) Effective tax rates for discontinued operations Effective Tax Rate For Discontinued Operations Effective Tax Rate For Discontinued Operations Tax benefit (expense) Discontinued Operation, Tax Effect of Discontinued Operation Income from discontinued operations before taxes Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax Valuation allowance Operating Loss Carryforwards Operating Loss Carryforwards Operating Loss Carryforwards, Expiration Date Operating Loss Carryforward Expiration Date Operating Loss Carryforward Expiration Date Income tax year is subject future examinations by federal tax authorities and local tax authorities Income Tax Examination Period Income Tax Examination Period Unrecognized Income Tax Benefits Unrecognized Income Tax Benefits Unrecognized Income Tax Benefits Income Tax Examination, Penalties and Interest Accrued Income Tax Examination, Penalties and Interest Accrued Current State and Local Tax Expense (Benefit) Current State and Local Tax Expense (Benefit) Current Foreign Tax Expense (Benefit) Current Foreign Tax Expense (Benefit) Current Income Tax Expense (Benefit) Current Income Tax Expense (Benefit) Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Foreign Deferred Foreign Income Tax Expense (Benefit) Deferred Income Tax Expense (Benefit) Deferred Income Tax Expense (Benefit) Income tax expense (benefit) Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Foreign Income (Loss) from Continuing Operations before Income Taxes, Foreign Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Deferred Tax Assets, Gross Deferred Tax Assets, Net of Valuation Allowance Deferred Tax Liabilities, Goodwill and Intangible Assets Deferred Tax Liabilities, Investments Deferred Tax Liabilities, Property, Plant and Equipment Deferred Tax Liabilities, Prepaid Expenses Deferred Tax Liabilities, Deferred Expense, Capitalized Research and Development Costs Deferred Tax Liabilities, Other Deferred Tax Liabilities, Gross Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount Tax Credit Carryforward, Amount Tax Credit Carryforward, Amount Tax Credit Carry Forward Expiration Year Tax Credit Carry Forward Expiration Year Tax credit carry forward expiration year. Decrease in Unrecognized Tax Benefits is Reasonably Possible Decrease in Unrecognized Tax Benefits is Reasonably Possible Goodwill and Intangible Assets Disclosure [Abstract] Changes in Carrying Amount of Goodwill Schedule of Goodwill [Table Text Block] Intangible Assets Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block] Schedule of Finite-Lived Intangible Assets, Future Amortization Expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Selected Quarterly Financial Data (unaudited) Quarterly Financial Information [Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Health Care [Member] Health Care [Member] Healthcare. Education [Member] Education [Member] Education [Member] Business Advisory [Member] Business Advisory [Member] Business Advisory [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments [Member] Operating Segments [Member] Segment Reconciling Items [Member] Segment Reconciling Items [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Segment Assets: Segment Reporting Information, Additional Elements for Bank Presentation [Abstract] Total assets Assets Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Summary of Carrying Amounts of Debt Schedule of Long-term Debt Instruments [Table Text Block] Schedule of Maturities of Long-term Debt Schedule of Maturities of Long-term Debt [Table Text Block] Schedule of Notes Convertible Debt [Table Text Block] Summary of Interest Expense Recognized Interest Expense Disclosure [Table Text Block] Tabular disclosure of components of interest expense recognized during the period related to the convertible senior notes. Components of interest expense include the contractual interest coupon, the amortization of debt issuance costs, and the amortization of the debt discount. Restructuring and Related Activities [Abstract] Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Restructuring Type [Axis] Restructuring Type [Axis] Type of Restructuring [Domain] Type of Restructuring [Domain] Employee Costs [Member] Employee Costs [Member] Employee Costs [Member] Office Space Reductions [Member] Office Space Reductions [Member] Office Space Reductions [Member] Other Restructuring [Member] Other Restructuring [Member] Restructuring Charges [Line Items] Restructuring Cost and Reserve [Line Items] Restructuring Reserve [Roll Forward] Restructuring Reserve [Roll Forward] Restructuring reserve, period start Restructuring Reserve Restructuring additions Increase (Decrease) in Restructuring Reserve Payments for restructuring Payments for Restructuring Restructuring reserve adjustments Restructuring Reserve, Accrual Adjustment Noncashrestructuringadjustments Noncashrestructuringadjustments Adjustment to the amount of restructuring charges incurred in the period for noncash activities. Restructuring reserve, period end Fair Value Disclosures [Abstract] Long-term debt Estimated fair value Long-term Debt, Fair Value Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Equity Incentive Plans Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Unrecognized Tax Benefit Likely to Decrease Unrecognized Tax Benefit Likely to Decrease Unrecognized Tax Benefit Likely to Decrease - amount reasonably possible to expire Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Unrecognized tax benefits, beginning balance Decrease based on tax positions related to the prior year Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Additions based on tax positions related to the current year Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Unrecognized tax benefits, ending balance Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-09 [Member] Accounting Standards Update 2016-09 [Member] ASU2018-02 [Member] ASU2018-02 [Member] ASU2018-02 [Member] Accounting Standards Update 2014-09 [Member] Accounting Standards Update 2014-09 [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock [Member] Common Stock [Member] Treasury Stock [Member] Treasury Stock [Member] Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Accumulated Other Comprehensive Income (Loss) [Member] AOCI Attributable to Parent [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance Stockholders' Equity Attributable to Parent Beginning balance, shares Shares, Issued Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Share-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Issuance of common stock in connection with: Issuance Of Common Stock In Connection With [Abstract] Issuance Of Common Stock In Connection With [Abstract] Restricted stock awards, net of cancellations Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Stock Issued During Period, Shares, Acquisitions Stock Issued During Period, Shares, Acquisitions Restricted stock awards, net of cancellations, shares Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Stock Issued During Period, Value, Stock Options Exercised Stock Issued During Period, Value, Stock Options Exercised Exercise of stock options, shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Business acquisition Stock Issued During Period, Value, Acquisitions Shares redeemed for employee tax withholdings Adjustments Related to Tax Withholding for Share-based Compensation Shares redeemed for employee tax withholdings, shares Shares Paid for Tax Withholding for Share Based Compensation Income tax benefit on share-based compensation Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation Share repurchases Stock Repurchased and Retired During Period, Value Share repurchases, shares Stock Repurchased and Retired During Period, Shares Ending balance Ending balance, shares Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months Long-term Debt, Maturities, Repayments of Principal in Year Two Long-term Debt, Maturities, Repayments of Principal in Year Two Long-term Debt, Maturities, Repayments of Principal in Year Three Long-term Debt, Maturities, Repayments of Principal in Year Three Long-term Debt, Maturities, Repayments of Principal in Year Four Long-term Debt, Maturities, Repayments of Principal in Year Four Long-term Debt, Maturities, Repayments of Principal in Year Five Long-term Debt, Maturities, Repayments of Principal in Year Five Long-term Debt, Maturities, Repayments of Principal after Year Five Long-term Debt, Maturities, Repayments of Principal after Year Five Valuation and Qualifying Accounts [Abstract] Summary of Allowances for Doubtful Accounts and Unbilled Services and Valuation Allowance for Deferred Tax Assets Schedule Of Valuation And Qualifying Accounts Reserves Table [Text Block] A schedule of allowance and reserve accounts including their beginning and ending balances, as well as a reconciliation by type of activity during the period. Schedule of Restructuring Reserve by Type of Cost Schedule of Restructuring Reserve by Type of Cost [Table Text Block] Income Taxes Income Tax Uncertainties, Policy [Policy Text Block] Income Taxes Income Tax Disclosure [Text Block] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Restricted Stock Awards [Member] Restricted Stock [Member] Performance-based stock activity [Member] Performance Shares [Member] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Scenario, Forecast [Member] Scenario, Forecast [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Nonvested performance-based shares outstanding Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Nonvested And Unearned Performance Shares Nonvested And Unearned Performance Shares As of the balance sheet date, the number of shares included in the non-vested balance that are still in their performance period or whose earned percentage has not yet been determined. Forfeited, number of shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Aggregate fair value of stock vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Major Types of Debt and Equity Securities [Domain] Convertible Debt Securities [Member] Convertible Debt Securities [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest Rate Swap [Member] Interest Rate Swap [Member] Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Contingent Consideration Liability [Member] Contingent Consideration Liability [Member] Contingent Consideration Liability [Member] Underlying Asset Class [Axis] Underlying Asset Class [Axis] Underlying Asset Class [Domain] Underlying Asset Class [Domain] Deferred Compensation Plan Assets [Member] Deferred Compensation Plan Assets [Member] Deferred Compensation Plan Assets [Member] Liabilities, Fair Value Disclosure [Abstract] Liabilities, Fair Value Disclosure [Abstract] Assets, Fair Value Disclosure [Abstract] Assets, Fair Value Disclosure [Abstract] Financial and Nonfinancial Liabilities, Fair Value Disclosure Financial and Nonfinancial Liabilities, Fair Value Disclosure Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Innosight Holdings, LLC [Member] Innosight Holdings, LLC [Member] Innosight Holdings, LLC [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Effective date of acquisition Business Acquisition, Effective Date of Acquisition Outstanding stock from the existing shareholders Business Acquisition, Percentage of Voting Interests Acquired Acquisition date fair value of the consideration Business Combination, Consideration Transferred Borrowings under credit facility Business Combination, Consideration Transferred, Liabilities Incurred Common stock issued Business Acquisition, Equity Interest Issued or Issuable, Number of Shares Acquisition date fair value Business Combination, Consideration Transferred, Equity Interests Issued and Issuable Share Price Share Price Contingent consideration related to business acquisitions Business Combination, Contingent Consideration, Liability Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High Weighted-average amortization period Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Goodwill expected to be deductible for income tax purpose Business Acquisition, Goodwill, Expected Tax Deductible Amount Operating income (loss) Amortization of Intangible Assets Amortization of Intangible Assets Expenses incurred Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Cost Expensed Pro Forma Adjustments, Additional Expense Pro Forma Adjustments, Additional Expense Pro Forma Adjustments, Additional Expense Revenue from Contract with Customer [Abstract] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Performance Obligation Satisfied in Prior Period [Axis] Performance Obligation Satisfied in Prior Period [Axis] Performance Obligation Satisfied in Prior Period [Axis] Performance Obligation Satisfied in Prior Period [Domain] Performance Obligation Satisfied in Prior Period [Domain] [Domain] for Performance Obligation Satisfied in Prior Period [Axis] Release of Allowance [Member] Release of Allowance [Member] Release of Allowance [Member] Change in Estimated Variable Consideration [Member] Change in Estimated Variable Consideration [Member] Change in Estimated Variable Consideration [Member] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Revenue, Remaining Performance Obligation Revenue, Remaining Performance Obligation Fair Value Disclosures - Contingent Consideration Reconciliation [Abstract] Fair Value Disclosures - Contingent Consideration Reconciliation [Abstract] Change in Fair Value, Reason [Axis] Change in Fair Value, Reason [Axis] Change in Fair Value, Reason [Axis] Change in Fair Value, Reason [Domain] Change in Fair Value, Reason [Domain] [Domain] for Change in Fair Value, Reason [Axis] Foreign Currency Gain (Loss) [Member] Foreign Currency Gain (Loss) [Member] Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease) Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease) Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Senior Secured Credit Facility [Member] Senior Secured Credit Facility [Member] Senior Secured Credit Facility [Member] Promissory Note due 2024 [Member] Promissory Note due 2024 [Member] Promissory Note due 2024 [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Warrant [Member] Warrant [Member] Note Hedge [Member] Note Hedge [Member] Note Hedge [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Base Rate [Member] Base Rate [Member] London Interbank Offered Rate (LIBOR) [Member] London Interbank Offered Rate (LIBOR) [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Aggregate principal amount Debt Instrument, Unamortized Discount Number of common shares converted upon debt conversion for each $1000 principal amount Debt Instrument, Convertible, Conversion Ratio Principal amount of notes per conversion Principal Amount Per Note The principal, or par, value of each note issued. Conversion price of convertible notes (in USD per share) Debt Instrument, Convertible, Conversion Price Optional right of debt instrument holders to convert debt instrument into cash, portion of principal amount Percentage Of Principal Paid Upon Exercise Of Put Percentage of principal amount required to be paid upon a debt holder's exercise of the put option following a fundamental change as defined in the indenture. Earliest conversion date Debt Instrument Convertible Date The earliest date on which the debt instrument can be converted into equity if none of the other conversion conditions have been met. Number of least trading days required within 30 consecutive trading days Debt Instrument, Convertible, Threshold Consecutive Trading Days Number of consecutive trading days Number Of Consecutive Period Of Trading Number of consecutive trading days during the last month of the preceding quarter in which the closing price on 20 such days must meet the stock price threshold defined in the indenture. Percentage of applicable conversion price Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger Concentration risk percentage Minimum Trading Price Percentage The minimum trading price as a percentage of the product of the last reported share price and the conversion rate of the notes. Effective interest rate of debt Debt Instrument, Interest Rate, Effective Percentage Remaining life of notes Debt Instrument, Convertible, Remaining Discount Amortization Period Payments of Debt Issuance Costs Payments of Debt Issuance Costs Liability issuance costs Debt Issuance Costs Assigned To Liability Total debt issuance costs assigned to the liability component of the convertible senior notes based on the relative fair value of the liability component to the total value of the notes issued. Equity issuance costs Issuance Costs Assigned To Equity Total issuance costs assigned to the equity component of the convertible senior notes based on the relative fair value of the equity component to the total value of the notes issued. Common stock purchased (in shares) Common Stock Underlying Convertible Senior Note And Related Transactions The number of shares of common stock underlying the convertible senior notes as well as the warrants and convertible note hedge transactions purchased concurrently with the issuance of the convertible senior notes. Aggregate amount for convertible hedge Payments For Note Hedges The cash outflow associated with the amount paid for convertible senior note hedges. Common stock price (in USD per share) Class of Warrant or Right, Exercise Price of Warrants or Rights Aggregate proceeds from the sale of warrants Proceeds from Issuance of Warrants Deferred income taxes, net Deferred Tax Liabilities, Net, Noncurrent Deferred tax asset Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Line of credit current borrowing capacity Line of Credit Facility, Current Borrowing Capacity Period of revolving credit facility Period Of Revolving Credit Facility Period of time between issuance and maturity of the revolving credit facility. Maturity date Line of Credit Facility, Expiration Date Optional increase In revolver Optional Increase In Revolver Optional increase in revolver. Aggregate principal amount - Senior secured credit facility Line of Credit Facility, Maximum Borrowing Capacity Debt Instrument, Basis Spread on Variable Rate Debt Instrument, Basis Spread on Variable Rate Required payment on revolver related to convertible debt maturity term Required Payment On Revolver Related To Convertible Debt Maturity Term Required payment on revolver related to convertible debt maturity term. Percentage of pledged voting stock in domestic subsidiaries Percentage Of Pledged Voting Stock In Domestic Subsidiaries The percentage of pledged voting stock or other equity instruments in the domestic subsidiaries to secure the revolver and term loan. Percentage of pledged voting stock in foreign subsidiaries Percentage Of Pledged Voting Stock In Foreign Subsidiaries The percentage of pledged voting stock or other equity instruments in the foreign subsidiaries to secure the revolver and term loan. Maximum consolidated leverage ratio Debt Instrument, Covenant, Consolidated Leverage Ratio, Maximum Debt Instrument, Covenant, Consolidated Leverage Ratio, Maximum Minimum interest coverage ratio Debt Instrument, Covenant, Interest Coverage Ratio, Minimum Debt Instrument, Covenant, Interest Coverage Ratio, Minimum Actual consolidated leverage ratio Debt Instrument, Covenant, Actual Consolidated Leverage Ratio Debt Instrument, Covenant, Actual Consolidated Leverage Ratio Actual interest coverage ratio Debt Instrument, Covenant, Actual Interest Coverage Ratio Debt Instrument, Covenant, Actual Interest Coverage Ratio Debt Instrument, Maturity Date Debt Instrument, Maturity Date Repayment of Principal at Maturity Date Repayment of Principal at Maturity Date Repayment of Principal at Maturity Date Duration of LIBOR Duration Of Libor The duration of LIBOR which is used to calculate the interest received from the counterparty. Percentage of weighted average interest rate of borrowings Debt, Weighted Average Interest Rate Outstanding letters of credit Letters of Credit Outstanding, Amount Unused borrowing capacity under Credit Agreement Line of Credit Facility, Remaining Borrowing Capacity Property and equipment, net Debt Instrument, Interest Rate, Stated Percentage Debt Instrument, Interest Rate, Stated Percentage Debt Conversion, Original Debt, Due Date of Debt Debt Conversion, Original Debt, Due Date of Debt Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Nonvested stock, number of shares, beginning balance Granted, number of shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Vested, number of shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Nonvested stock, number of shares, ending balance Weighted Average Grant Date Fair Value (in dollars) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Nonvested stock, weighted average grant date fair value, beginning balance (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Weighted average grant date fair value (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Vested, weighted average grant date fair value (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited, weighted average grant date fair value (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Nonvested stock, weighted average grant date fair value, ending balance (in USD per share) Number of Operating Segments Number of Operating Segments Statement of Financial Position [Abstract] Assets Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Receivables from clients, net Accounts Receivable, Net, Current Costs in Excess of Billings, Current Costs in Excess of Billings, Current Income tax receivable Income Taxes Receivable, Current Prepaid Expense and Other Assets, Current Prepaid Expense and Other Assets, Current Total current assets Assets, Current Deferred Tax Assets, Net, Noncurrent Deferred Tax Assets, Net, Noncurrent Long-term investment Long-term Investments Other non-current assets Other Assets, Noncurrent Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Goodwill Goodwill Total assets Liabilities and stockholders’ equity Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued expenses and other current liabilities Accrued Liabilities, Current Accrued payroll and related benefits Employee-related Liabilities, Current Business Combination, Contingent Consideration, Liability, Current Business Combination, Contingent Consideration, Liability, Current Long-term Debt, Current Maturities Long-term Debt, Current Maturities Deferred revenues Deferred Revenue, Current Total current liabilities Liabilities, Current Non-current liabilities: Liabilities, Noncurrent [Abstract] Deferred compensation and other liabilities Deferred Compensation And Other Liabilities Aggregate carrying value, as of the balance sheet date, of the liabilities for all deferred compensation arrangements and all other non current obligations not separately disclosed in the balance sheet payable beyond one year (or the operating cycle, if longer). Business Combination, Contingent Consideration, Liability, Noncurrent Business Combination, Contingent Consideration, Liability, Noncurrent Long-term debt, net of current portion Long-term Debt, Excluding Current Maturities Deferred lease incentives Deferred Rent Credit, Noncurrent Total non-current liabilities Liabilities, Noncurrent Commitments and contingencies Commitments and Contingencies Stockholders’ equity Stockholders' Equity Attributable to Parent [Abstract] Common Stock, Value, Issued Common Stock, Value, Issued Treasury Stock, Value Treasury Stock, Value Additional paid-in capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders’ equity Total liabilities and stockholders’ equity Liabilities and Equity Equity [Abstract] Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments, Contingencies and Guarantees Commitments Contingencies and Guarantees [Text Block] Common stock, par value (in USD per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Treasury stock, shares Treasury Stock, Shares Financing Arrangements Debt Disclosure [Text Block] Commitments And Contingencies [Table] Commitments And Contingencies [Table] Commitments And Contingencies [Table] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Chicago, Illinois [Member] Chicago, Illinois [Member] Chicago, Illinois [Member] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Gain (Loss) Related to Litigation Settlement Gain (Loss) Related to Litigation Settlement Lease Expiration Date Lease Expiration Date Period of renewal option that allow continue to occupy the majority of office space Lessee, Operating Lease, Renewal Term Rental expense, including operating costs and taxes Operating Leases, Rent Expense, Net Guarantees in the form of letters of credit Renewal Option, Expiration Date Renewal Option, Expiration Date Renewal Option, Expiration Date Derivative Instruments and Hedging Activity Derivative Instruments and Hedging Activities Disclosure [Text Block] Valuation and Qualifying Accounts Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] Fair value measurement policy Fair Value Measurement, Policy [Policy Text Block] Wisconsin Office [Member] Wisconsin Office [Member] Wisconsin Office [Member] San Francisco Office [Member] San Francisco Office [Member] San Francisco Office [Member] Corporate, Non-Segment [Member] Corporate, Non-Segment [Member] Employee Severance [Member] Employee Severance [Member] Restructuring Plan [Axis] Restructuring Plan [Axis] Restructuring Plan [Domain] Restructuring Plan [Domain] Restructuring additions Restructuring Charges Loss on disposal Gain (Loss) on Disposition of Business Restructuring charge liability Interest rate swap agreement, effective date Derivative, Inception Date Interest rate swap agreement, end date Derivative, Maturity Date Interest rate swap agreement for a notional amount Derivative, Notional Amount Percentage of fixed rate Interest Rate Swap Fixed Interest Rate The fixed interest rate we pay to the counterparty of the interest rate swap. Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred Loss reclassification from accumulated OCI to income, estimate of time to transfer Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimate of Time to Transfer At U.S. statutory tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent State income taxes, net of federal benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Percent Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Percent Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent Effective Income Tax Rate Reconciliation,Other Reconciling Items, Percent Effective Income Tax Rate Reconciliation,Other Reconciling Items, Percent Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Percent Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Percent Effective Income Tax Rate Reconciliation, Disallowed Executive Compensation, Percent Effective Income Tax Rate Reconciliation, Disallowed Executive Compensation, Percent Effective Income Tax Rate Reconciliation, Disallowed Executive Compensation, Percent Effective Income Tax Rate Reconciliation, Contingent Consideration Liabilities, Change In Fair Value, Percent Effective Income Tax Rate Reconciliation, Contingent Consideration Liabilities, Change In Fair Value, Percent Effective Income Tax Rate Reconciliation, Contingent Consideration Liabilities, Change In Fair Value, Percent Effective Income Tax Rate Reconciliation, Global Intangible Low-Taxed Income, Percent Effective Income Tax Rate Reconciliation, Global Intangible Low-Taxed Income, Percent Effective Income Tax Rate Reconciliation, Global Intangible Low-Taxed Income, Percent Meals and entertainment Effective Income Tax Rate Reconciliation, Nondeductible Expense, Meals and Entertainment, Percent Effective Income Tax Rate Reconciliation, Realized Investment (Gains) Losses, Percent Effective Income Tax Rate Reconciliation, Realized Investment (Gains) Losses, Percent Effective Income Tax Rate Reconciliation, Realized Investment (Gains) Losses, Percent Valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent Foreign source income Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent Tax credits / Section 199 Deduction Effective Income Tax Rate Reconciliation, Tax Credit, Percent Net tax (benefit) expense related to “check-the-box” election (1) Effective Income Tax Rate Reconciliation Net Tax Benefit Related to Check the Box Election Effective Income Tax Rate Reconciliation Net Tax Benefit Related to Check the Box Election Other Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Effective income tax expense rate for continuing operations Acquisitions Business Combination Disclosure [Text Block] Accounting Standards Update 2016-02 [Member] Accounting Standards Update 2016-02 [Member] Adjustments for Error Corrections [Axis] Adjustments for Error Corrections [Axis] Adjustments for Error Correction [Domain] Adjustments for Error Correction [Domain] Costs in Excess of Billings, Current [Member] Costs in Excess of Billings, Current [Member] Costs in Excess of Billings, Current [Member] Deferred Tax Asset [Domain] Deferred Tax Asset [Domain] Deferred Tax Asset, Net, Noncurrent [Member] Deferred Tax Asset, Net, Noncurrent [Member] Deferred Tax Asset, Net, Noncurrent [Member] Cash and Cash Equivalents [Line Items] Cash and Cash Equivalents [Line Items] Cumulative Effect on Retained Earnings, Tax Cumulative Effect on Retained Earnings, Tax Cumulative Effect on Retained Earnings, before Tax Cumulative Effect on Retained Earnings, before Tax Operating Lease, Liability Operating Lease, Liability Operating Lease, Right-of-Use Asset Operating Lease, Right-of-Use Asset Capitalized Contract Cost, Net Capitalized Contract Cost, Net Goodwill, Impairment Loss Goodwill, Impairment Loss Depreciated over and estimated useful life Property, Plant and Equipment, Estimated Useful Lives Cash and Cash Equivalent maturity period Cash And Cash Equivalent Maturity Period The maximum length of time over which an instrument may mature to be classified as cash and cash equivalents. Error Corrections and Prior Period Adjustments, Description Error Corrections and Prior Period Adjustments, Description Unamortized capitalized software development costs Capitalized Software Development Costs for Software Sold to Customers Number of billing arrangements for revenue recognition Number Of Billing Arrangements For Revenue Recognition The number of billing arrangements the Company uses on client engagements. The nature of each arrangement will help determine the appropriate revenue recognition for that engagement. Amortized capitalized software development costs Capitalized Computer Software, Amortization Impairment of long-lived assets Impairment of Long-Lived Assets Held-for-use Impairment of intangible assets and goodwill Goodwill and Intangible Asset Impairment Number of Reporting Units Number of Reporting Units Sponsorship and advertising costs Foreign currency translation gain (loss), net of tax Capitalized Contract Cost, Amortization Capitalized Contract Cost, Amortization Cumulative effect on retained earnings, net of tax Cumulative Effect on Retained Earnings, Net of Tax Schedule of Property and Equipment Property, Plant and Equipment [Table Text Block] Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table] Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Customer relationships [Member] Customer Relationships [Member] Trade names [Member] Trade Names [Member] Customer contracts [Member] Customer Contracts [Member] Non-competition Agreements [Member] Noncompete Agreements [Member] Off-Market Favorable Lease [Member] Off-Market Favorable Lease [Member] Technology-Based Intangible Assets [Member] Technology And Software [Member] Technology And Software [Member] Publishing content [Member] Publishing Content [Member] Publishing Content [Member] Acquired Finite-Lived Intangible Assets [Line Items] Acquired Finite-Lived Intangible Assets [Line Items] Intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Useful life in years Finite-Lived Intangible Asset, Useful Life Components of Segment Information Segment Reporting Information, Profit (Loss) [Abstract] Segment operating income as a percentage of segment revenues Operating Income Loss As Percent Of Revenues Segment operating income (loss) as percent of segment revenues. Other operating expenses and gains Other Selling, General and Administrative Expense Gain (Loss) Related To Litigation Settlement And Other Operating Gains Gain (Loss) Related To Litigation Settlement And Other Operating Gains Amount of (gain) loss recognized in settlement of litigation and insurance claims and other operating activities. Also includes the amount of increase (decrease) in the fair value of a contingent consideration liability, including, but not limited to, differences arising upon settlement. Depreciation and amortization expense Depreciation, Depletion and Amortization, Nonproduction Other expense, net Nonoperating Income (Expense) Income (loss) from continuing operations before taxes Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Intangible assets Finite-Lived Intangible Assets, Net [Abstract] Gross carrying amount Finite-Lived Intangible Assets, Gross Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Earnings Per Share [Abstract] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Employee Stock Option [Member] Employee Stock Option [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Total anti-dilutive securities Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Quarterly Financial Information [Table Text Block] Quarterly Financial Information [Table Text Block] Employee Benefit and Deferred Compensation Plans Compensation and Employee Benefit Plans [Text Block] Accounting Changes and Error Corrections [Abstract] Net Income (Loss) Attributable to Parent Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Application Of Proportionate Performance [Member] Application Of Proportionate Performance [Member] Application Of Proportionate Performance [Member] Error Corrections and Prior Period Adjustments Restatement [Line Items] Error Corrections and Prior Period Adjustments Restatement [Line Items] Finite-Lived Intangible Assets, Amortization Expense, Year Two Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months Finite-Lived Intangible Assets, Amortization Expense, Year Three Finite-Lived Intangible Assets, Amortization Expense, Year Two Finite-Lived Intangible Assets, Amortization Expense, Year Five Finite-Lived Intangible Assets, Amortization Expense, Year Three Finite-Lived Intangible Assets, Amortization Expense, after Year Five Finite-Lived Intangible Assets, Amortization Expense, Year Four Finite-Lived Intangible Assets, Amortization Expense, after Year Five Finite-Lived Intangible Assets, Amortization Expense, Year Five Earnings Per Share Earnings Per Share [Text Block] Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract] Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract] Accounts receivable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Prepaid expenses and other current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets Property and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract] Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract] Accounts payable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable Accrued expenses and other current liabilities Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Accrued Liabilities And Other Liabilities Current Business combination recognized identifiable assets acquired and liabilities assumed accrued liabilities and other liabilities current. Accrued payroll and related benefits Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Current Liabilities Accrued Payroll and Benefits Business combination recognized identifiable assets acquired and liabilities assumed current liabilities accrued payroll and benefits. Deferred revenues Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue Total identifiable net assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Total purchase price Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Current: Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal State Foreign Total current Deferred: Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Total deferred Income tax expense for continuing operations Income Tax Expense (Benefit) Schedule of Goodwill [Table] Schedule of Goodwill [Table] Enterprise Solutions and Analytics [Member] Enterprise Solutions and Analytics [Member] Enterprise Solutions and Analytics [Member] Reporting Unit [Axis] Reporting Unit [Axis] Reporting Unit [Axis] Reporting Unit [Domain] Reporting Unit [Domain] [Domain] for Reporting Unit [Axis] Strategy and Innovation [Member] Strategy and Innovation [Member] Strategy and Innovation [Member] Life Sciences [Member] Life Sciences [Member] Life Sciences [Member] Goodwill [Line Items] Goodwill [Line Items] Goodwill, Written off Related to Sale of Business Unit Goodwill, Written off Related to Sale of Business Unit Goodwill, Impairment Loss Goodwill, Transfers Goodwill, Transfers Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount Accelerated Share Repurchases [Table] Accelerated Share Repurchases [Table] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] Share Repurchase Program [Member] Share Repurchase Program [Member] Share Repurchase Program [Member] Accelerated Share Repurchases [Line Items] Accelerated Share Repurchases [Line Items] Share repurchase authorized amount Stock Repurchase Program, Authorized Amount Shares repurchased Stock Repurchased and Retired During Period, Value Stock Repurchase Program, Remaining Authorized Repurchase Amount Stock Repurchase Program, Remaining Authorized Repurchase Amount Operating Leases, Future Minimum Payments Due, Next Twelve Months Operating Leases, Future Minimum Payments Due, Next Twelve Months Operating Leases, Future Minimum Payments, Due in Two Years Operating Leases, Future Minimum Payments, Due in Two Years Operating Leases, Future Minimum Payments, Due in Three Years Operating Leases, Future Minimum Payments, Due in Three Years Operating Leases, Future Minimum Payments, Due in Four Years Operating Leases, Future Minimum Payments, Due in Four Years Operating Leases, Future Minimum Payments, Due in Five Years Operating Leases, Future Minimum Payments, Due in Five Years Operating Leases, Future Minimum Payments, Due Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Operating lease obligations, total Operating Leases, Future Minimum Payments Due Operating Leases, Future Minimum Payments Receivable, Current Operating Leases, Future Minimum Payments Receivable, Current Operating Leases, Future Minimum Payments Receivable, in Two Years Operating Leases, Future Minimum Payments Receivable, in Two Years Operating Leases, Future Minimum Payments Receivable, in Three Years Operating Leases, Future Minimum Payments Receivable, in Three Years Operating Leases, Future Minimum Payments Receivable, in Four Years Operating Leases, Future Minimum Payments Receivable, in Four Years Operating Leases, Future Minimum Payments Receivable, in Five Years Operating Leases, Future Minimum Payments Receivable, in Five Years Operating Leases, Future Minimum Payments Receivable, Thereafter Operating Leases, Future Minimum Payments Receivable, Thereafter Sublease income, total Operating Leases, Future Minimum Payments Receivable Disaggregation of Revenue [Abstract] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Domain] Timing of Transfer of Good or Service [Domain] Transferred over Time [Member] Transferred over Time [Member] Transferred at Point in Time [Member] Transferred at Point in Time [Member] Employee Type [Axis] Employee Type [Axis] Employee Type [Axis] Employee Type [Domain] Employee Type [Domain] [Domain] for Employee Type [Axis] Full-time Billable Consultants [Member] Full-time Billable Consultants [Member] Full-time Billable Consultants [Member] Full-time Equivalents [Member] Full-time Equivalents [Member] Full-time Equivalents [Member] Contract with Customer, Basis of Pricing [Axis] Contract with Customer, Basis of Pricing [Axis] Contract with Customer, Basis of Pricing [Domain] Contract with Customer, Basis of Pricing [Domain] Fixed-price Contract [Member] Fixed-price Contract [Member] Time-and-materials Contract [Member] Time-and-materials Contract [Member] Performance-based [Member] Performance-based [Member] Performance-based [Member] Software Service, Support and Maintenance Arrangement [Member] Software Service, Support and Maintenance Arrangement [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Future Minimum Rental Commitments Under Non-Cancelable Leases and Sublease Income Lease Minimum Future Obligation And Minimum Future Receivable Under Sublease Table [Text Block] Tabular disclosure of future minimum payments required in the aggregate and for each of the five succeeding fiscal years for capital leases and operating leases having initial or remaining noncancelable lease terms in excess of one year and the the total minimum rentals to be received in the future under noncancelable subleases, and as of the balance sheet date. Segment Information Segment Reporting Disclosure [Text Block] Description of Business Nature of Operations [Text Block] Goodwill and Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Business Combination, Separately Recognized Transactions [Table] Business Combination, Separately Recognized Transactions [Table] Business Combination, Separately Recognized Transactions [Line Items] Business Combination, Separately Recognized Transactions [Line Items] Business acquisition, pro forma revenue Business Acquisition, Pro Forma Revenue Business acquisition, pro forma net income (loss) Business Acquisition, Pro Forma Net Income (Loss) Business acquisition, pro forma earnings per share, basic (in USD per share) Business Acquisition, Pro Forma Earnings Per Share, Basic Business acquisition, pro forma earnings per share, diluted (in USD per share) Business Acquisition, Pro Forma Earnings Per Share, Diluted Schedule of Restricted Stock Activity Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Schedule of Performance-Based Stock Activity Schedule of Nonvested Performance-based Units Activity [Table Text Block] Schedule of Stock Option Activity Share-based Compensation, Stock Options, Activity [Table Text Block] Commissions Expense, Policy [Policy Text Block] Commissions Expense, Policy [Policy Text Block] Schedule of Cumulative Effect Adjustments ScheduleofCumulativeEffectAdjustments [Table Text Block] ScheduleofCumulativeEffectAdjustments [Table Text Block] Income Tax Expense for Continuing Operations Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Components of Income from Continuing Operations Before Income Tax Expense Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Reconciliation of Statutory Income Tax Rate to Our Effective Tax Rate for Continuing Operations Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Net Deferred Tax Liabilities for Continuing Operations Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits Schedule of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns Roll Forward [Table Text Block] Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income (loss) to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization Amortization of debt discount and issuance costs Amortization of Debt Issuance Costs and Discounts Provision for Doubtful Accounts Provision for Doubtful Accounts Allowances for doubtful accounts and unbilled services Allowances For Doubtful Accounts And Unbilled Services Changes to allowance for doubtful accounts and unbilled services to an amount that approximates their net realizable value (the amount expected to be collected). Deferred income taxes Deferred Income Taxes and Tax Credits Loss (gain) on sale of businesses Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability Changes in operating assets and liabilities, net of acquisitions and divestitures: Increase (Decrease) in Operating Capital [Abstract] (Increase) decrease in receivables from clients Increase (Decrease) in Accounts Receivable (Increase) decrease in unbilled services Increase (Decrease) in Unbilled Receivables (Increase) decrease in current income tax receivable / payable, net Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable (Increase) decrease in other assets Increase (Decrease) in Other Operating Assets Increase (decrease) in accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Increase (decrease) in accrued payroll and related benefits Increase (Decrease) in Employee Related Liabilities Increase (decrease) in deferred revenues Increase (Decrease) in Deferred Revenue Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Purchases of property and equipment, net Investment in life insurance policies Payments for (Proceeds from) Life Insurance Policies Proceeds from Life Insurance Policy Proceeds from Life Insurance Policy Purchases of businesses, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Capitalization of internally developed software Payments to Develop Software Proceeds from note receivable Proceeds from Sale and Collection of Notes Receivable Proceeds from Divestiture of Businesses, Net of Cash Divested Proceeds from Divestiture of Businesses, Net of Cash Divested Proceeds from Divestiture of Businesses Payments for (Proceeds from) Businesses and Interest in Affiliates Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from exercises of stock options Proceeds from Stock Options Exercised Shares redeemed for employee tax withholdings Payments Related to Tax Withholding for Share-based Compensation Share repurchases Proceeds from (Repurchase of) Equity Proceeds from borrowings under credit facility Proceeds from Long-term Lines of Credit Repayments of debt Repayments of Long-term Debt Payments for debt issuance costs Deferred acquisition payments Payment of Contingent Consideration Liabilities Payment of Contingent Consideration Liabilities Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations Effect of exchange rate changes on cash Effect of Exchange Rate on Cash and Cash Equivalents Net increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents at beginning of the period Cash and cash equivalents at end of the period Supplemental disclosure of cash flow information: Supplemental Cash Flow Information [Abstract] Non-cash investing and financing activities: Non Cash InvestingFinancing Activities [Abstract] Non Cash Investing and Financing Activities [Abstract] Property & equipment expenditures and capitalized software included in accounts payable and accrued expenses Capital Expenditures Incurred but Not yet Paid Notes Assumed Notes Assumed Common stock issued related to business acquisitions Stock Issued Cash paid during the year for: Cash Paid During Year For [Abstract] Cash paid during year for. Interest Interest Paid Income taxes Income Taxes Paid Fair Value Disclosures - Convertible Debt Investment Reconciliation [Abstract] Fair Value Disclosures - Convertible Debt Investment Reconciliation [Abstract] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Shorelight Holdings Llc [Member] Shorelight Holdings Llc [Member] Shorelight Holdings Llc [Member] Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Reconciliation of Basic and Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Summary of Anti-dilutive Securities Excluded from Computation of Weighted Average Common Stock Equivalents Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block] Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block] Derivatives, Policy [Policy Text Block] Derivatives, Policy [Policy Text Block] Basis of Presentation and Principles of Consolidation Consolidation, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Revenue Recognition Revenue Recognition, Policy [Policy Text Block] Allowances for Doubtful Accounts and Unbilled Services Receivables, Policy [Policy Text Block] Direct Costs and Reimbursable Expenses Cost of Sales, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Concentrations of Credit Risk Concentration Risk, Credit Risk, Policy [Policy Text Block] Investments Marketable Securities, Available-for-sale Securities, Policy [Policy Text Block] Property and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Software Development Costs Research, Development, and Computer Software, Policy [Policy Text Block] Impairment of Long-Lived Assets Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Goodwill Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Business Combinations Business Combinations Policy [Policy Text Block] Deferred Lease Incentives Lessee, Leases [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Share-Based Compensation Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Sponsorship and Advertising Costs Advertising Costs, Policy [Policy Text Block] Debt Issuance Costs Debt, Policy [Policy Text Block] Foreign Currency Foreign Currency Transactions and Translations Policy [Policy Text Block] Segment Reporting Segment Reporting, Policy [Policy Text Block] New Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Preferred stock, shares authorized Preferred Stock, Shares Authorized Preferred stock, shares approved or issued Preferred Stock, Shares Issued Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Two Thousand And Twelve Plan [Member] Two Thousand And Twelve Plan [Member] Two Thousand And Twelve Plan [Member] Stock Ownership Participation Program [Member] Stock Ownership Participation Program [Member] Stock Ownership Participation Program [Member] Two Thousand and Four Plan [Member] Two Thousand and Four Plan [Member] Two Thousand and Four Plan [Member] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Executive Officer [Member] Executive Officer [Member] Option Indexed to Issuer's Equity, Type [Axis] Option Indexed to Issuer's Equity, Type [Axis] Option Indexed to Issuer's Equity, Type [Domain] Option Indexed to Issuer's Equity, Type [Domain] Increase in number of shares authorized for issuance Share Based Compensation Arrangement By Share Based Payment Award Plan Modification Increase In Authorized Shares Share Based Compensation Arrangement By Share Based Payment Award Plan Modification Increase In Authorized Shares Shares available for issuance Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Restricted stock granted as a percentage of purchased shares Share-Based Compensation Arrangement By Share-Based Payment Award, Restricted Stock Granted, As A Percentage Of Purchased Shares Share-Based Compensation Arrangement By Share-Based Payment Award, Restricted Stock Granted, As A Percentage Of Purchased Shares Retirement eligible provision, description Retirement Eligible Provision Description A narrative description of the retirement eligible provision adopted under the share based payment plan. Retirement eligible provision, minimum age Retirement Eligible Provision Minimum Age Retirement Eligible Provision Minimum Age Retirement eligible provision, minimum years of service Retirement Eligible Provision Minimum Term Of Service Retirement eligible provision minimum term of service. Share-based compensation expense Allocated Share-based Compensation Expense Income tax benefits Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Unrecognized compensation cost Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Unrecognized compensation cost, Period Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Stock option awards granted Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Award vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Stock options contractual term Share Based Compensation Arrangement By Share Based Payment Award Expiration Period One The contractual term of stock options, after which the stock options will expire. Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Foreign currency translation adjustments, beginning balance Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax Foreign currency translation adjustments, ending balance Foreign currency translation adjustment, net of tax Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Unrealized loss on investment, beginning balance Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Unrealized loss on investments Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Other Comprehensive Income (Loss), Available for Sale Investment, Unrealized gain (loss) Other Comprehensive Income (Loss), Available for Sale Investment, Unrealized gain (loss) Other Comprehensive Income (Loss), Available for Sale Investment, Unrealized gain (loss) Unrealized loss on investment, ending balance Unrealized gain (loss) on cash flow hedges, beginning balance Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax Change in fair value Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Reclassification adjustment into earnings Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Unrealized gain (loss) on cash flow hedges, ending balance Change in fair value Reclassification adjustment into earnings Goodwill Goodwill, Gross Accumulated impairment losses Goodwill, Impaired, Accumulated Impairment Loss Goodwill, net beginning balance Goodwill recorded in connection with business combinations Goodwill, Acquired During Period Foreign currency translation Goodwill, Foreign Currency Translation Gain (Loss) Goodwill, net ending balance Total Weighted Average Grant Date Fair Value (in dollars) Number of Options (in thousands) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding, shares, beginning balance Forfeited or expired, shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period Outstanding, shares, ending balance Exercisable, shares, ending balance Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Weighted Average Exercise Price (in dollars) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Beginning balance, weighted average exercise price (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Ending balance, weighted average exercise price (in USD per share) Exercisable, weighted average exercise price (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Weighted-average remaining contractual term (years), option outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Weighted-average remaining contractual term (years), options exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Aggregate intrinsic value, option outstanding, beginning balance Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Aggregate intrinsic value, option outstanding, ending balance Aggregate intrinsic value, options exercisable, ending balance Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Property and Equipment, Net Property, Plant and Equipment Disclosure [Text Block] Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Statement of Comprehensive Income [Abstract] Revenues and reimbursable expenses: Revenues [Abstract] Total revenues and reimbursable expenses Direct costs and reimbursable expenses (exclusive of depreciation and amortization shown in operating expenses): Direct Costs And Reimbursable Expenses Exclusive Of Depreciation And Amortization Shown In Operating Expenses [Abstract] Direct Costs And Reimbursable Expenses Exclusive Of Depreciation And Amortization Shown In Operating Expenses [Abstract] Direct costs Cost of Services Amortization of intangible assets and software development costs Cost of Services, Depreciation and Amortization Reimbursable expenses Cost of Reimbursable Expense Total direct costs and reimbursable expenses Cost of Revenue Operating expenses and other operating gains: Operating Expenses [Abstract] Selling, general and administrative expenses Selling, General and Administrative Expense Restructuring charges (1) Other losses (gains), net Depreciation and amortization Total operating expenses and other losses (gains), net Operating Expenses Operating income (loss) Other income (expense), net Nonoperating Income (Expense) [Abstract] Interest Expense Net Of Interest Income Interest Expense Net Of Interest Income The cost of borrowed funds accounted for as interest that was charged against earnings during the period, net of immaterial amounts of interest income recognized during the period associated with banking, investing or other activities. Other Nonoperating Income (Expense) Other Nonoperating Income (Expense) Nonoperating Income (Expense) Income tax expense (benefit) Net income (loss) from continuing operations Net income (loss) Net income, per basic share (in USD per share) Net income, per diluted share (in USD per share) Comprehensive income (loss): Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Foreign currency translation adjustments, net of tax Unrealized gain (loss) on investment, net of tax Unrealized gain (loss) on cash flow hedging instruments, net of tax Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Other comprehensive income Earnings Per Share Reconciliation [Abstract] Weighted average common shares outstanding-basic Weighted average common stock equivalents Weighted Average Number Diluted Shares Outstanding Adjustment Weighted average common shares outstanding- diluted Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Domain] Initial Application Period Cumulative Effect Transition [Domain] Calculated under Revenue Guidance in Effect before Topic 606 [Member] Calculated under Revenue Guidance in Effect before Topic 606 [Member] Difference between Revenue Guidance in Effect before and after Topic 606 [Member] Difference between Revenue Guidance in Effect before and after Topic 606 [Member] Other Comprehensive Income (Loss), Net of Tax [Abstract] Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Tax Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Tax Amount of tax expense (benefit) related to, after reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature. Other Comprehensive Income (Loss), Available-for-sale Securities, Tax Other Comprehensive Income (Loss), Available-for-sale Securities, Tax Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Capital Structure Stockholders' Equity Note Disclosure [Text Block] Payments to Acquire Businesses, Gross Payments to Acquire Businesses, Gross Consideration transferred net working capital adjustment Business Combination Consideration Transferred Net Working Capital Adjustment Business combination consideration transferred net working capital adjustment. Disaggregation of Revenue [Table Text Block] Disaggregation of Revenue [Table Text Block] Components of Segment Information Schedule of Segment Reporting Information, by Segment [Table Text Block] Segment Assets Reconciliation of Assets from Segment to Consolidated [Table Text Block] Valuation and Qualifying Accounts Disclosure [Table] Valuation and Qualifying Accounts Disclosure [Table] Allowances for doubtful accounts and unbilled services [Member] Allowance for Doubtful Accounts [Member] Valuation allowance for deferred tax assets [Member] Valuation Allowance of Deferred Tax Assets [Member] Valuation and Qualifying Accounts Disclosure [Line Items] Valuation and Qualifying Accounts Disclosure [Line Items] Beginning balance Valuation Allowances and Reserves, Balance Additions Valuation Allowances and Reserves, Additions for Charges to Cost and Expense Deductions Valuation Allowances and Reserves, Deductions Ending balance Restructuring Charges Restructuring and Related Activities Disclosure [Text Block] Summary of Fair Value of Consideration Transferred Schedule Of Fair Value Of Consideration Received [Table Text Block] Schedule Of Fair Value Of Consideration Received [Table Text Block] Preliminary Allocation of the Purchase Price to the Fair Value of Assets Acquired and Liabilities Assumed Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Schedule of Components of Identifiable Intangible Assets Acquired and their Estimated Useful Lives Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] Summary of Supplemental Pro Forma Consolidated Results of Operations Business Acquisition, Pro Forma Information [Table Text Block] Change in Contract with Customer, Asset [Abstract] Contract with Customer, Performance Obligation Satisfied in Previous Period Contract with Customer, Performance Obligation Satisfied in Previous Period Change in Contract with Customer, Asset and Liability [Abstract] Change in Contract with Customer, Asset and Liability [Abstract] Contract Asset, Period Increase (Decrease) Contract Asset, Period Increase (Decrease) Amount of increase (decrease) in the right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than the passage of time. Deferred Revenue, Period Increase (Decrease) Deferred Revenue, Period Increase (Decrease) Contract with Customer, Asset, Net Contract with Customer, Asset, Net Deferred Revenue, Revenue Recognized Deferred Revenue, Revenue Recognized Components of Accumulated Other Comprehensive Loss, Net of Tax Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Revenue from Contract with Customer [Text Block] Revenue from Contract with Customer [Text Block] Total loss from discontinued operations before taxes Income tax benefit (2) Depreciation expense for property and equipment Depreciation Accounting Advisory Practice [Member] Accounting Advisory Practice [Member] The Accounting Advisory Practice of a consulting group which has been sold for non-cash or part non-cash transaction. Non Cash Consideration For Sale Of Discontinued Operation Non Cash Consideration For Sale Of Discontinued Operation The face value of the promissory note received for the sale of discontinued operations. Note Receivable, Term Note Receivable, Term Note Receivable, Term Reduction in Principal of Amended Promissory Note Reduction in Principal of Amended Promissory Note Reduction in Principal of Amended Promissory Note Long-term Investments Debt Instrument, Convertible, Carrying Amount of Equity Component