Accelerated Share Repurchases [Line Items] Accelerated Share Repurchases [Line Items] Accelerated Share Repurchases [Table] Accelerated Share Repurchases [Table] The Accounting Advisory Practice of a consulting group which has been sold for non-cash or part non-cash transaction. Accounting Advisory Practice [Member] Accounting Advisory Practice [Member] 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. Accounting For Convertible Senior Notes [Policy Text Block] Convertible Senior Notes Accounting Policies [Abstract] Accounting Policies [Abstract] Accounts Payable, Current Accounts payable Accounts Receivable, Net, Current Receivables from clients, net The accrual for payments to acquire businesses including earn-out payments, which represents additional purchase price earned by selling shareholders subsequent to the business combination as certain financial performance targets and conditions are met, and due to be paid within one year (or one operating cycle, if longer) of the balance sheet date. Accrued Consideration For Business Acquisitions Current Accrued consideration for business acquisitions Accrued Income Taxes, Current Income tax payable Accrued Liabilities, Current Accrued expenses Accrued Liabilities [Member] Accrued expenses [Member] Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Accumulated depreciation and amortization Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Unrealized Loss on Investment, Ending balance Unrealized Loss on Investment, Beginning balance Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax Unrealized gain (loss) on cash flow hedges, Ending balance Unrealized gain (loss) on cash flow hedges, Beginning balance Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax Foreign Currency Translation Adjustments, Ending balance Foreign Currency Translation Adjustments, Beginning balance Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated Other Comprehensive Loss, Ending balance Accumulated Other Comprehensive Loss, Beginning balance Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Components of accumulated other comprehensive loss, net of tax Accumulated Other Comprehensive Income (Loss) [Member] Accumulated Other Comprehensive Income (Loss) [Member] Principal amount of additional convertible debt instrument. Additional Long Term Investments Purchase of additional convertible notes Additional Paid in Capital, Common Stock Additional paid-in capital Additional Paid-in Capital [Member] Additional Paid-In Capital [Member] Adjustments Related to Tax Withholding for Share-based Compensation Shares redeemed for employee tax withholdings Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt Equity component of convertible senior notes, net of tax and issuance costs The amount of decrease in additional paid in capital (APIC) resulting from the purchase of convertible senior note hedges. Adjustments To Additional Paid In Capital Note Hedge Purchase of convertible senior note hedges, net of tax Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Share-based compensation Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation Income tax benefit on share-based compensation Adjustments to Additional Paid in Capital, Warrant Issued Issuance of warrants Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Advertising Costs, Policy [Policy Text Block] Sponsorship and Advertising Costs Allocated Share-based Compensation Expense Share-based compensation expense Other Segments [Member] All Other [Member] Allowance for Doubtful Accounts [Member] Allowances for doubtful accounts and unbilled services [Member] 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). Allowances For Doubtful Accounts And Unbilled Services Allowances for doubtful accounts and unbilled services Amendment Flag Amendment Flag Amortization of Debt Discount (Premium) Amortization of debt discount Amortization of Financing Costs Amortization of debt issuance costs Amortization of Financing Costs and Discounts Amortization of debt discount and issuance costs Amortization of Intangible Assets Intangible assets amortization expense The amount of brokerage fees incurred related to the execution of a sublease agreement for the space exited. Amount Of Brokerage Fees Related To Sub Lease Arrangement Brokerage fees related to sublease arrangement Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Total anti-dilutive securities Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Assets Total assets Total assets Assets [Abstract] Assets Assets, Current Total current assets Assets, Current [Abstract] Current assets: Assets, Fair Value Disclosure Assets, fair value Assets Held under Capital Leases [Member] Assets under Capital Lease [Member] Asset under Construction [Member] Assets under Construction [Member] Award Type [Axis] Award Type [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Black-Scholes option pricing model. Black Scholes Option Pricing Model [Member] Black-Scholes option-pricing model [Member] Bluestone [Member] Bluestone [Member] Blue Stone International, LLC [Member] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Effective Date of Acquisition Effective date of acquisition Business Acquisition, Equity Interest Issued or Issuable, Value Assigned Purchase consideration common stock issued Business Acquisition [Member] Business Acquisition [Member] Business Acquisition [Member] Business Combination, Consideration Transferred Purchase price of the business acquired Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability Contingent consideration remeasurement gain Business Combination, Contingent Consideration, Liability Contingent consideration related to business acquisitions Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Intangible assets related to acquisition Business Combinations Policy [Policy Text Block] Business Combinations Capital Expenditures Incurred but Not yet Paid Property and equipment expenditures included in accounts payable and accrued expenses Capitalized Computer Software, Amortization Amortized capitalized software development costs Capitalized Software Development Costs for Software Sold to Customers Unamortized capitalized software development costs Capital Leases, Future Minimum Payments Due Capital Lease Obligations, Total Capital Leases, Future Minimum Payments Due, Next Twelve Months Capital Lease Obligations, 2015 Capital Leases, Future Minimum Payments Due in Five Years Capital Lease Obligations, 2019 Capital Leases, Future Minimum Payments Due in Four Years Capital Lease Obligations, 2018 Capital Leases, Future Minimum Payments Due in Three Years Capital Lease Obligations, 2017 Capital Leases, Future Minimum Payments Due in Two Years Capital Lease Obligations, 2016 Capital Leases, Future Minimum Payments Due Thereafter Capital Lease Obligations, Thereafter 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] 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] The maximum length of time over which an instrument may mature to be classified as cash and cash equivalents. Cash And Cash Equivalent Maturity Period Cash and Cash Equivalents maturity period Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents at end of the period Cash and cash equivalents at beginning of the period Cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Net increase in cash and cash equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Cash and Cash Equivalents Cash paid during year for. Cash Paid During Year For [Abstract] Cash paid during the year for: Chicago, Illinois [Member] Chicago, Illinois [Member] Chicago, Illinois [Member] Claim Against Breach Of Contract [Member] Claim Against Breach Of Contract [Member] Claim against breach of contract [Member] Claim Against Damage On Reputation [Member] Claim Against Damage On Reputation [Member] Claim against damage on reputation and defamation [Member] Class of Warrant or Right, Exercise Price of Warrants or Rights Common stock price per share Combined Receivables And Unbilled Service Balances [Member] Combined Receivables And Unbilled Service Balances [Member] Combined Receivables and Unbilled Services Balances [Member] Commitments and Contingencies Commitments and Contingencies Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Commitments And Contingencies [Table] Commitments And Contingencies [Table] Commitments And Contingencies [Table] Commitments Contingencies and Guarantees [Text Block] Commitments, Contingencies and Guarantees Common Stock [Member] Common Stock [Member] Common Stock, Par or Stated Value Per Share Common stock, par value Common Stock, Shares Authorized Common stock, shares authorized Common Stock, Shares, Issued Common stock, shares issued 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. Common Stock Underlying Convertible Senior Note And Related Transactions Common stock purchased Common Stock, Value, Issued Common stock; $0.01 par value; 500,000,000 shares authorized; 24,976,395 and 25,246,565 shares issued at December 31, 2014 and December 31, 2013, respectively Compensation and Employee Benefit Plans [Text Block] Employee Benefit and Deferred Compensation Plans Components of Deferred Tax Assets [Abstract] Deferred tax assets: Components of Deferred Tax Liabilities [Abstract] Deferred tax liabilities: Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive income Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Comprehensive income: Comprehensive Income (Loss) Note [Text Block] Other Comprehensive Income (Loss) Computers Related Equipment And Software [Member] Computers Related Equipment And Software [Member] Computers, Related Equipment and Software [Member] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk, Credit Risk, Policy [Policy Text Block] Concentrations of Credit Risk Concentration Risk, Percentage Customer percentage of consolidated receivables and unbilled services or consolidated net sales revenue Concentration Risk Type [Domain] Concentration Risk Type [Domain] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Consolidation, Policy [Policy Text Block] Basis of Presentation and Principles of Consolidation Contingent Acquisition Liability [Member] Contingent Acquisition Liability [Member] Contingent acquisition liability [Member] The value of the contingent consideration given in a business acquisition that is not payable until a future period. Contingent Consideration Transaction Value Related To Business Acquisition Contingent consideration related to business acquisitions Convertible Debt Securities [Member] Convertible Debt Investment [Member] Convertible Debt [Table Text Block] Schedule of Notes Convertible Senior Notes [Line Items] Convertible Senior Notes [Line Items] Convertible Senior Notes [Line Items] Cost of Reimbursable Expense Reimbursable expenses Cost of Revenue Total direct costs and reimbursable expenses Cost of Sales, Policy [Policy Text Block] Direct Costs and Reimbursable Expenses Cost of Services Direct costs Cost of Services, Depreciation and Amortization Amortization of intangible assets and software development costs The base amount of dividends which may be declared by the entity without restriction under the loan agreement. The total dividend restriction amount is equal to the base amount plus a percentage of cumulative consolidated net income and a percentage of the net cash proceeds from equity issuances. Credit Agreement Dividends Restriction Amount Credit Agreement, dividends restriction amount Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Current Federal Tax Expense (Benefit) Federal Current Fiscal Year End Date Current Fiscal Year End Date Current Foreign Tax Expense (Benefit) Foreign Current Income Tax Expense (Benefit) Total current Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Current: Current State and Local Tax Expense (Benefit) State Customer Concentration Risk [Member] Customer Concentration Risk [Member] Customer Contracts [Member] Customer Contracts [Member] Customer Relationships [Member] Customer Relationships [Member] Debt Conversion, Original Debt, Due Date of Debt Debt instrument maturity date Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Disclosure [Text Block] Financing Arrangements Debt Instrument, Convertible, Carrying Amount of Equity Component Carrying value of equity component Equity component Debt Instrument, Convertible, Conversion Price Conversion price of convertible notes Debt Instrument, Convertible, Conversion Ratio Number of common shares converted upon debt conversion for each $1000 principal amount The earliest date on which the debt instrument can be converted into equity if none of the other conversion conditions have been met. Debt Instrument Convertible Date Earliest conversion date Debt Instrument, Convertible, Remaining Discount Amortization Period Remaining life of notes Debt Instrument, Convertible, Threshold Consecutive Trading Days Number of least trading days required within 30 consecutive trading days Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger Percentage of applicable conversion price Debt Instrument, Face Amount Aggregate principal amount Proceeds Debt Instrument, Interest Rate, Effective Percentage Effective interest rate of debt Debt Instrument, Interest Rate, Stated Percentage Debt instrument interest rate Debt Instrument [Line Items] Debt Instrument [Line Items] Debt Instrument, Maturity Date Debt instrument maturity date Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument, Unamortized Discount Less: debt discount, net of amortization Debt Issuance Cost Debt issuance costs 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. Debt Issuance Costs Assigned To Liability Liability issuance costs Debt, Policy [Policy Text Block] Debt Issuance Costs Debt Security [Axis] Debt Security [Axis] Debt, Weighted Average Interest Rate Percentage of weighted average interest rate of borrowings The payment of deferred acquisition amounts, which represents additional purchase price earned by selling shareholders subsequent to the business combination as certain financial performance targets and conditions are met. Deferred Acquisition Payments Deferred acquisition payments Deferred Acquisition Payments [Member] Deferred Acquisition Payments [Member] Deferred acquisition payment [Member] The payment of deferred acquisition amounts, which represents additional purchase price earned by selling shareholders subsequent to the business combination as certain financial performance targets and conditions are met, plus accrued interest. Deferred Acquisition Payments Plus Accrued Interest Deferred acquisition payment 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 Compensation And Other Liabilities Deferred compensation and other liabilities Deferred Compensation And Other Liabilities [Member] Deferred Compensation And Other Liabilities [Member] Deferred compensation and other liabilities [Member] Deferred Compensation Liability, Current and Noncurrent Deferred compensation liability Deferred Federal Income Tax Expense (Benefit) Federal Deferred Foreign Income Tax Expense (Benefit) Foreign Deferred Income Taxes and Tax Credits Deferred income taxes Deferred Income Tax Expense (Benefit) Total deferred Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Deferred: Cash outflows to vendors under deferred payment arrangements that arose from purchases of property, plant and equipment or other productive assets. Deferred Payments to Acquire Property, Plant, and Equipment Deferred payments for purchase of property and equipment Deferred Rent Credit, Noncurrent Deferred lease incentives Deferred Revenue, Current Deferred revenues Deferred State and Local Income Tax Expense (Benefit) State Amount before allocation of valuation allowances of deferred tax assets attributable to deductible temporary differences from deferred lease incentives. Deferred Tax Assets Current Deferred Lease Incentive Deferred lease incentives Deferred Tax Assets, Gross Total deferred tax assets Deferred Tax Assets, Hedging Transactions Convertible note hedge transactions Deferred Tax Assets, Net Net deferred tax liability for continuing operations Deferred Tax Assets, Net of Valuation Allowance Net deferred tax assets Deferred Tax Assets, Net of Valuation Allowance, Current Deferred income taxes, net Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Deferred tax asset Deferred Tax Assets, Operating Loss Carryforwards Net operating loss carry-forwards Deferred Tax Assets, Other Tax Carryforwards Other Amount before allocation of valuation allowances of deferred tax assets attributable to deductible temporary differences from revenue recognition. Deferred Tax Assets Revenue Recognition Revenue recognition Deferred Tax Assets, Tax Credit Carryforwards Tax credits Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Share-based compensation Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities Accrued payroll and other liabilities Deferred Tax Assets, Valuation Allowance Valuation allowance Valuation allowance Deferred Tax Liabilities, Net Total deferred tax liabilities Deferred tax liabilities convertible note discount. Deferred Tax Liabilities Convertible Note Discount Convertible note discount Deferred Tax Liabilities, Goodwill and Intangible Assets Intangibles and Goodwill Deferred Tax Liabilities, Net, Noncurrent Deferred income taxes, net Deferred tax liability Deferred Tax Liabilities, Other Other Deferred Tax Liabilities, Prepaid Expenses Prepaid expenses Deferred Tax Liabilities, Property, Plant and Equipment Property and equipment Defined Contribution Plan, Cost Recognized Employer matching contributions Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay Employer contributions up to percent of employee's salaries Depreciation Depreciation expense for property and equipment