Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Business Combinations [Abstract] Summary of Fair Value of Consideration Transferred Schedule Of Fair Value Of Consideration Transferred Table [Table Text Block] Schedule Of Fair Value Of Consideration Transferred 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] 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 Future Amortization Expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Goodwill and Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] 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] Unvested restricted stock awards Restricted Stock [Member] Convertible senior notes Convertible Debt Securities [Member] Warrants related to the issuance of convertible senior notes Warrant [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 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] Studer Group Studer Group [Member] Studer Group [Member] Sky Analytics Inc Sky Analytics [Member] Sky Analytics [Member] Rittman Mead [Member] Rittman Mead [Member] Rittman Mead [Member] Acquisition Date [Line Items] Acquisition Date [Line Items] Acquisition Date [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 Date of acquisition agreement Business Acquisition, Date of Acquisition Agreement 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 Acquisition date fair value based on closing price Share Price 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 Net Revenue Sales Revenue, Services, Net Operating income Operating Income (Loss) Amortization expenses for intangible assets Amortization of Intangible Assets Expenses incurred Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Cost Expensed Cash Payments to Acquire Businesses, Gross Fair value of contingent consideration Business Acquisition Contingent Consideration At Fair Value1 Business acquisition contingent consideration at fair value1. Intangible Asset Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Goodwill Goodwill Commitments and Contingencies Disclosure [Abstract] Commitments And Contingencies [Table] Commitments And Contingencies [Table] Commitments And Contingencies [Table] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Claim against damage on reputation and defamation Claim Against Damage On Reputation [Member] Claim Against Damage On Reputation [Member] Claim against breach of contract Claim Against Breach Of Contract [Member] Claim Against Breach Of Contract [Member] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Loss contingency damages sought value Loss Contingency, Damages Sought, Value Litigation Settlement, Amount Litigation Settlement, Amount Loss contingency accrual Loss Contingency Accrual Insurance Settlements Receivable Insurance Settlements Receivable Guarantees in the form of letters of credit Letters of Credit Outstanding, Amount Assets acquired: 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 Deferred income tax asset Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets, Current Property and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Intangible assets Liabilities assumed: 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 Deferred income tax liability Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent Other non-current liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities 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 Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activity Derivative Instruments and Hedging Activities Disclosure [Text Block] Segment Reporting [Abstract] Segment Information Segment Reporting Disclosure [Text Block] Equity [Abstract] Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] 1.25% convertible senior notes due 2019 Convertible Debt [Member] Senior secured credit facility Senior Secured Credit Facility [Member] Senior Secured Credit Facility [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Net carrying amount Long-term Debt Current maturities of debt Long-term Debt, Current Maturities Long-term debt, net of current portion Long-term Debt, Excluding Current Maturities Components of Other Comprehensive Income (Loss), Net of Tax Comprehensive Income (Loss) [Table Text Block] Components of Accumulated Other Comprehensive Income (Loss), Net of Tax Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] 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 Unbilled services, net Unbilled Services Net Current Revenues recognized in excess of billings, which are expected to be collected within one year of the balance sheet date, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Income tax receivable Income Taxes Receivable, Current Deferred income taxes, net Deferred Tax Assets, Net of Valuation Allowance, Current Prepaid expenses and other current assets Prepaid Expenses And Other Current Assets Sum of the amounts paid in advance for capitalized costs that will be expensed with the passage of time or the occurrence of a triggering event, and will be charged against earnings within one year or the normal operating cycle, if longer. Also includes the aggregate carrying amount, as of the balance sheet date, of current assets not separately presented elsewhere in the balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer). Total current assets Assets, Current Property and equipment, net Property, Plant and Equipment, Net Long-term investment Long-term Investments Other non-current assets Other Assets, Noncurrent Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Total assets Assets Liabilities and stockholders’ equity Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued expenses Accrued Liabilities, Current Accrued payroll and related benefits Employee-related Liabilities, Current Current maturities of long-term debt 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). Deferred lease incentives Deferred Rent Credit, Noncurrent Deferred income taxes, net Deferred Tax Liabilities, Net, Noncurrent Total non-current liabilities Liabilities, Noncurrent Commitments and contingencies Commitments and Contingencies Stockholders’ equity Stockholders' Equity Attributable to Parent [Abstract] Common stock; $0.01 par value; 500,000,000 shares authorized; 25,142,424 and 24,976,395 shares issued at September 30, 2015 and December 31, 2014, respectively Common Stock, Value, Issued Treasury stock, at cost, 2,207,972 and 2,097,173 shares at September 30, 2015 and December 31, 2014, respectively Treasury Stock, Value Additional paid-in capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders’ equity Stockholders' Equity Attributable to Parent Total liabilities and stockholders’ equity Liabilities and Equity 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] Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Common Stock [Member] Treasury Stock Treasury Stock [Member] Additional Paid-In Capital Additional Paid-in Capital [Member] Retained Earnings Retained Earnings [Member] Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning Balance Beginning Balance, shares Shares, Issued Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent 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 Restricted stock awards, net of cancellations, shares Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Business acquisition Stock Issued During Period, Value, Acquisitions Business acquisition, shares Stock Issued During Period, Shares, Acquisitions Share-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition 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 Shares repurchased, shares Stock Repurchased and Retired During Period, Shares Ending Balance Ending Balance, shares Accounting Policies [Abstract] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Internal Use Software Internal Use Software, Policy [Policy Text Block] Presentation of Debt Issuance Costs Debt Issuance Costs Policy [Text Block] Debt Issuance Costs Policy [Text Block] Amendments to the Consolidation Analysis Amendment To Consolidation Analysis Policy [Text Block] Amendment To Consolidation Analysis Policy [Text Block] Revenue from Contracts with Customers Revenue Recognition, Policy [Policy Text Block] Debt Accounting For Convertible Senior Notes [Policy Text Block] Disclosure of accounting policy for convertible senior notes including the process of calculating the debt discount and related treatment of the equity and liability components. Derivatives and Hedging Derivatives, Policy [Policy Text Block] Fair Value Measurements and Disclosures Fair Value of Financial Instruments, Policy [Policy Text Block] Segment Reporting Segment Reporting, Policy [Policy Text Block] Earnings Per Share Earnings Per Share [Text Block] Common stock, par value (USD per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (shares) Common Stock, Shares Authorized Common stock, shares issued (shares) Common Stock, Shares, Issued Treasury stock, shares (shares) Treasury Stock, Shares Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [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 contracts Customer Contracts [Member] Customer relationships Customer Relationships [Member] Non-competition agreements Noncompete Agreements [Member] Trade names Trade Names [Member] Technology and software Technology And Software [Member] Technology And Software [Member] Publishing content Publishing Content [Member] Publishing Content [Member] License License [Member] License [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Intangible assets Finite-Lived Intangible Assets, Net [Abstract] Useful Life in Years Finite-Lived Intangible Asset, Useful Life Gross Carrying Amount Finite-Lived Intangible Assets, Gross Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Components of Segment Information Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Huron Healthcare Health Care [Member] Healthcare. Huron Education and Life Sciences Education And Life Sciences [Member] Education And Life Sciences [Member] Huron Legal Huron Legal [Member] Huron Legal [Member] Huron Business Advisory Huron Business Advisory [Member] Huron Business Advisory [Member] Goodwill [Line Items] Goodwill [Line Items] Goodwill Goodwill, Gross Accumulated impairment Goodwill, Impaired, Accumulated Impairment Loss Goodwill [Roll Forward] Goodwill [Roll Forward] Goodwill, net beginning balance Goodwill recorded in connection with business acquisitions Goodwill, Acquired During Period Foreign currency translation Goodwill, Translation Adjustments Goodwill, net ending balance Income Tax Disclosure [Abstract] Effective tax rates Effective Income Tax Rate Reconciliation, Percent Realizable income tax benefit from check-the-box election Realizable Tax Benefit from Intercompany Receivable Write Off The realizable tax benefit expected from the one-time "check-the-box" election to treat a whole owned foreign subsidiary as a disregarded entity. Unrecognized tax benefit from check-the-box election Unrecognized Tax Benefit from Intercompany Receivable Write Off The unrealized tax benefit from our one-time "check-the-box" election to treat a wholly owned foreign subsidiary as a disregarded entity. Net tax benefit recognized from check-the-box election Net Income Tax Benefit Recognized from Intercompany Receivable Write Off The recognized net tax benefit from the one-time "check-the-box" election to treat a wholly owned foreign subsidiary as a disregarded entity. Expense related to valuation allowance and deferred tax liability Establishment Of Valuation Allowance And Increased Deferred Tax Liability Expense related to the establishment of a valuation allowance and increased deferred tax liabilities as a result of the check-the-box election. Restructuring and Related Activities [Abstract] Restructuring Charges Restructuring and Related Activities 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] Revenues Business Acquisition, Pro Forma Revenue Net income Business Acquisition, Pro Forma Net Income (Loss) Business Acquisition, Pro Forma Earnings Per Share, Basic Business Acquisition, Pro Forma Earnings Per Share, Basic Business Acquisition, Pro Forma Earnings Per Share, Diluted Business Acquisition, Pro Forma Earnings Per Share, Diluted Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss) Attributable to Parent Adjustments to reconcile net income 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 Share-based compensation Share-based Compensation Amortization of debt discount and issuance costs Amortization of Financing Costs and Discounts Allowances for doubtful accounts and unbilled services Allowances For Doubtful Accounts And Unbilled Services Amount of the current period expense and reduction of revenue charged against operations, the offset which is generally to the allowance for doubtful accounts for the purpose of reducing receivables 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 Changes in operating assets and liabilities, net of acquisitions: 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 Payments to Acquire Property, Plant, and Equipment Investment in life insurance policies Payments for (Proceeds from) Life Insurance Policies Purchases of businesses Payments to Acquire Businesses, Net of Cash Acquired Purchases of convertible debt investment Payments to Acquire Available-for-sale Securities, Debt Capitalization of internally developed software costs Payments to Develop Software Proceeds from note receivable Proceeds from Sale and Collection of Notes Receivable 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 exercise of stock options Proceeds from Stock Options Exercised Shares redeemed for employee tax withholdings Payments Related to Tax Withholding for Share-based Compensation Tax benefit from share-based compensation Excess Tax Benefit from Share-based Compensation, Financing Activities Share repurchases Proceeds from (Repurchase of) Equity Proceeds from borrowings under credit facility Proceeds from Long-term Lines of Credit Repayments on credit facility Repayments of Long-term Debt Proceeds from Convertible Debt Proceeds from Convertible Debt Aggregate proceeds from the sale of warrants Proceeds from Issuance of Warrants Payments For Note Hedges Payments For Note Hedges The cash outflow associated with the amount paid for convertible senior note hedges. Payments for debt issue costs Payments of Debt Issuance Costs Payments for capital lease obligations Repayments of Long-term Capital Lease Obligations Deferred Payments To Acquire Property, Plant, And Equipment Deferred Payments To Acquire Property, Plant, And Equipment Deferred Payments To Acquire Property, Plant, And Equipment Deferred Acquisition Payments Deferred Acquisition Payments Deferred Acquisition Payments Net cash provided by 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 (decrease) increase 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 Financing Activities [Abstract] Non Cash Financing Activities [Abstract] Property and equipment expenditures included in accounts payable and accrued expenses Capital Expenditures Incurred but Not yet Paid Contingent consideration related to business acquisitions Contingent Consideration Transaction Value Related To Business Acquisition The value of the contingent consideration given in a business acquisition that is not payable until a future period. Common stock issued related to business acquisition Stock Issued Basis of Presentation Basis of Accounting [Text Block] Fair Value Disclosures [Abstract] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring Fair Value, Measurements, Recurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Significant Unobservable Inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Debt Security [Axis] Debt Security [Axis] Major Types of Debt Securities [Domain] Major Types of Debt Securities [Domain] Promissory note Promissory Note [Member] Promissory note. 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 investment Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest rate swaps Interest Rate Swap [Member] Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Contingent consideration for business acquisitions Contingent Consideration Liability [Member] Contingent Consideration Liability [Member] 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] Liabilities: Liabilities, Fair Value Disclosure [Abstract] Fair Value, Asset/Liability Assets, Fair Value Disclosure [Abstract] Assets, fair value Assets, Fair Value Disclosure Liabilities, fair value Financial and Nonfinancial Liabilities, Fair Value Disclosure 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] Line of Credit Facility [Table] Line of Credit Facility [Table] Convertible Debt Convertible Senior Notes [Line Items] Convertible Senior Notes [Line Items] Convertible Senior Notes [Line Items] Proceeds Debt Instrument, Face Amount Less: debt discount, net of amortization Debt Instrument, Unamortized Discount Equity component Debt Instrument, Convertible, Carrying Amount of Equity Component Acquisitions Business Combination Disclosure [Text Block] Financing Arrangements Debt Disclosure [Text Block] Number of operating segments Number of Operating Segments Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table] Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table] Acquired Finite-Lived Intangible Assets [Line Items] Acquired Finite-Lived Intangible Assets [Line Items] Derivative [Table] Derivative [Table] Derivative [Line Items] Derivative [Line Items] 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 Duration of LIBOR Duration Of Libor The duration of LIBOR which is used to calculate the interest received from the counterparty. Percentage of fixed rate Interest Rate Swap Fixed Interest Rate The fixed interest rate we pay to the counterparty of the interest rate swap. Anticipated net losses, net of tax, currently recorded in accumulated other comprehensive loss reclassified into earnings Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred Gain (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 Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Segment Reconciling Items Segment Reconciling Items [Member] All Other Other Segments [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Components of Segment Information Segment Reporting Information, Profit (Loss) [Abstract] Revenues Operating income (loss) 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. Reimbursable expenses Reimbursement Revenue Total revenues and reimbursable expenses Revenues Other operating expenses and gains Other Selling, General and Administrative Expense Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Other expense, net Nonoperating Income (Expense) Income before income tax expense Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Carrying Amounts And Estimated Fair Values Of Financial Instruments [Table] Carrying Amounts And Estimated Fair Values Of Financial Instruments [Table] Carrying Amounts And Estimated Fair Values Of Financial Instruments [Table] Carrying Amounts And Estimated Fair Values Of Financial Instruments [Line Items] Carrying Amounts And Estimated Fair Values Of Financial Instruments [Line Items] Carrying Amounts And Estimated Fair Values Of Financial Instruments [Line Items] Debt instrument interest rate Debt Instrument, Interest Rate, Stated Percentage Carrying Amount Estimated Fair Value Long-term Debt, Fair Value Accounting Changes and Error Corrections [Abstract] New Accounting Pronouncements New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Weighted average common shares outstanding – basic Weighted Average Number of Shares Outstanding, Basic Weighted average common stock equivalents Weighted Average Number Diluted Shares Outstanding Adjustment Weighted average common shares outstanding – diluted Weighted Average Number of Shares Outstanding, Diluted Earnings per share: Earnings Per Share, Basic and Diluted [Abstract] Basic (USD per share) Earnings Per Share, Basic Diluted (USD per share) Earnings Per Share, Diluted Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Corporate Office Corporate Office [Member] Corporate Office [Member] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] London Office [Member] London Office [Member] London Office [Member] Chicago, New York, and London Offices Chicago, New York, and London Offices [Member] Chicago, New York, and London Offices [Member] Restructuring Charges [Line Items] Restructuring Cost and Reserve [Line Items] Restructuring Charges [Abstract] Restructuring Charges [Abstract] Pretax restructuring expense Restructuring Charges Severance expense Severance Costs Lease payments, net of estimated sublease income charges Other Restructuring Costs Restructuring reserve related to accelerated depreciation Restructuring and Related Cost, Accelerated Depreciation Restructuring charge liability Restructuring Reserve Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Groups, Including Discontinued Operations, Name [Domain] Disposal Groups, Including Discontinued Operations, Name [Domain] Accounting Advisory Practice Accounting Advisory Practice [Member] The Accounting Advisory Practice of a consulting group which has been sold for non-cash or part non-cash transaction. Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Shorelight Holdings LLC Shorelight Holdings Llc [Member] Shorelight Holdings Llc [Member] Fair Value of Financial Instruments [Abstract] Financial Instruments, Owned, at Fair Value [Abstract] Promissory note received for sale of Accounting Advisory Non Cash Consideration For Sale Of Discontinued Operation The face value of the promissory note received for the sale of discontinued operations. Promissory note term Note Receivable, Term Note Receivable, Term Promissory note payable maturity date Held-to-maturity Securities, Debt Maturities, Date Discount rate used to measure fair value Fair Value Inputs, Discount Rate Investments in notes Purchase of additional convertible notes Additional Long Term Investments Principal amount of additional convertible debt instrument. Debt instrument maturity date Debt Instrument, Maturity Date Unrealized gain (loss) on investments - debt and equity securities Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Contingent consideration related to business acquisitions Business Combination, Contingent Consideration, Liability Number of businesses acquired Number of Businesses Acquired Contingent consideration remeasurement gain 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. Excludes claims within an insurance entity's normal claims settlement process. Aggregate principal amount Carrying value of equity component Closing price of common stock 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] Other non-current assets Other Noncurrent Assets [Member] Accrued expenses Accrued Liabilities [Member] Deferred compensation and other liabilities Deferred Compensation And Other Liabilities [Member] Deferred Compensation And Other 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 Financial Assets and Liabilities Measured at Fair Value on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Summary of Carrying Amount and Estimated Fair Value of Convertible Senior Notes Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Note Hedge Note Hedge [Member] Note Hedge [Member] Revolving Credit Facility Revolving Credit Facility [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] Base Rate Base Rate [Member] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Scenario One, Leverage Ratio Scenario One, Leverage Ratio [Member] Scenario One, Leverage Ratio [Member] Scenario Two, Leverage Ratio Scenario Two, Leverage Ratio [Member] Scenario Two, Leverage Ratio [Member] Debt instrument maturity date Debt Conversion, Original Debt, Due Date of Debt 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 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 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 Number of consecutive business days following consecutive trading days Debt instrument, Convertible, Threshold of Consecutive Business Days Following Consecutive Trading Days Debt instrument, Convertible, Threshold of Consecutive Business Days Following Consecutive Trading Days 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 Debt issuance costs Debt Issuance Cost 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 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 Common stock price per share Class of Warrant or Right, Exercise Price of Warrants or Rights Deferred tax liability Deferred tax asset Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Revolving Credit facility 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. Credit agreement expiration date Line of Credit Facility, Expiration Date Option to increase revolving credit facility Optional Increase In Revolver Optional increase in revolver. Maximum principle amount Line of Credit Facility, Maximum Borrowing Capacity Interest rate on borrowings Debt Instrument, Basis Spread on Variable Rate 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 other equity interests 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 other equity interests 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 consolidated 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 Percentage of weighted average interest rate of borrowings Debt, Weighted Average Interest Rate Outstanding letters of credit Unused borrowing capacity under Credit Agreement Line of Credit Facility, Remaining Borrowing Capacity Intangible assets amortization expense Estimated annual intangible assets amortization expense 2015 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months Estimated annual intangible assets amortization expense 2016 Finite-Lived Intangible Assets, Amortization Expense, Year Two Estimated annual intangible assets amortization expense 2017 Finite-Lived Intangible Assets, Amortization Expense, Year Three Estimated annual intangible assets amortization expense 2018 Finite-Lived Intangible Assets, Amortization Expense, Year Four Estimated annual intangible assets amortization expense 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Five Estimated annual intangible assets amortization expense 2020 Finite-Lived Intangible Assets, Amortization Expense, after Year Five Commitments, Contingencies and Guarantees Commitments Contingencies and Guarantees [Text Block] Summary of Carrying Amounts of Debt Schedule of Long-term Debt Instruments [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. Contractual interest coupon Interest Expense, Debt, Excluding Amortization Amortization of debt issuance costs Amortization of Financing Costs Amortization of debt discount Amortization of Debt Discount (Premium) Total interest expense Interest Expense, Debt Description of Business Nature of Operations [Text Block] Foreign currency translation adjustment, before taxes Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax Unrealized gain on investment, before taxes Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax Change in fair value, before taxes Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax Reclassification adjustments into earnings, before taxes Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax Net unrealized gain (loss), before taxes Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax, Portion Attributable to Parent Other comprehensive income (loss), before taxes Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent Foreign currency translation adjustment, tax (expense) benefit 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. Unrealized gain on investment, tax (expense) benefit Other Comprehensive Income (Loss), Available-for-sale Securities, Tax Change in fair value, tax (expense) benefit Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax Reclassification adjustments into earnings, tax (expense) benefit Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Net unrealized gain (loss), tax (expense) benefit Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax, Portion Attributable to Parent Other comprehensive income (loss), tax (expense) benefit Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Foreign currency translation adjustment, net of taxes Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Unrealized gain on investment, net of taxes Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Change in fair value, net of taxes Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Reclassification adjustments into earnings, net of taxes Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Net unrealized gain (loss), net of taxes Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Income Taxes Income Tax Disclosure [Text Block] Business Acquisition [Line Items] Business Acquisition [Line Items] Common stock Net working capital adjustment Business Combination Consideration Transferred Net Working Capital Adjustment Business combination consideration transferred net working capital adjustment. Total consideration transferred 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) losses: Operating Expenses [Abstract] Selling, general and administrative expenses Selling, General and Administrative Expense Restructuring charges Litigation and other (gains) losses Total operating expenses and other operating (gains) losses Operating Expenses Operating income 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 income (expense), net Other Nonoperating Income (Expense) Total other expense, net Income tax expense Income Tax Expense (Benefit) Net income Earnings per share: Weighted average shares used in calculating earnings per share: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (per share) Diluted (per share) Comprehensive income: Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Foreign currency translation loss, net of tax Unrealized gain on investment, net of tax Unrealized gain (loss) on cash flow hedging instruments, net of tax Other comprehensive income (loss) Comprehensive income Foreign Currency Translation Adjustments, Beginning balance Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax Foreign Currency Translation Adjustments, Current period change Foreign Currency Translation Adjustments, Ending balance Net Unrealized Gain (Loss) on Investment, Beginning balance Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Unrealized gain on investment, net of tax Net Unrealized Gain (Loss) on Investment, Ending balance Net Unrealized Losses on Derivatives, Beginning balance Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax Unrealized loss on cash flow hedging instruments, net of tax Net Unrealized Losses on Derivatives, Ending balance Accumulated Other Comprehensive Income (Loss), Beginning balance Accumulated Other Comprehensive (Income) Loss, Current period change Accumulated Other Comprehensive Income (Loss), Ending balance 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 Accelerated Share Repurchases [Table] Accelerated Share Repurchases [Table] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] October 2014 Share Repurchase Program October 2014 Share Repurchase Program [Member] October 2014 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, shares Share repurchases