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Exercise of options Stock Issued During Period, Value, Stock Options Exercised Goodwill and Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Stockholders’ equity Equity, Attributable to Parent [Abstract] Weighted average grant date fair value (in dollars per share) Restricted share awards granted (in dollars per share) Performance stock units granted (in dollars 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 Corporate Finance Restructuring Corporate Finance Restructuring [Member] Corporate Finance Restructuring [Member] Income Taxes Income Tax, Policy [Policy Text Block] Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Segments [Domain] Segments [Domain] Guarantor obligation, remaining guarantor capacity available Guarantor Obligation, Remaining Guarantor Capacity Available Guarantor Obligation, Remaining Guarantor Capacity Available Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Estimated revenues recognized Revenue, Estimated Revenue Recognized , Percentage Revenue, Estimated Revenue Recognized , Percentage Description Of Business And Summary Of Significant Accounting Policies [Line Items] Description Of Business And Summary Of Significant Accounting Policies [Line Items] Description Of Business And Summary Of Significant Accounting Policies [Line Items] 2028 Finite-Lived Intangible Asset, Expected Amortization, Year Four All Individuals All Individuals [Member] Corporate Finance Corporate Finance Segment [Member] Corporate Finance Segment Borrowings under revolving line of credit Proceeds from Lines of Credit PEO PEO [Member] Variable Rate Variable Rate [Axis] Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Schedule Of Balance Sheet Details Schedule of Other Assets and Other Liabilities [Table Text Block] Purchase and maturity of short-term investment Payments for (Proceeds from) Short-Term Investments Name Trading Arrangement, Individual Name Other Other Nonoperating Income (Expense) Goodwill Goodwill, Gross Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Intangible assets, net Intangible assets, Net Carrying Amount Intangible Assets, Net (Excluding Goodwill) Receivables [Abstract] Receivables [Abstract] Omnibus Plan 2017 Omnibus Plan Two Thousand Seventeen [Member] Omnibus Plan Two Thousand Seventeen [Member] Property, Plant and Equipment, Type [Axis] Long-Lived Tangible Asset [Axis] Entity Public Float Entity Public Float Commitment fee Line of Credit Facility, Unused Capacity, Commitment Fee Percentage Reclassification of negative additional paid-in capital Adjustments to Additional Paid in Capital, Reclassification Of Negative Additional Paid In Capital Adjustments to Additional Paid in Capital, Reclassification Of Negative Additional Paid In Capital Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Other expenses not deductible for tax purposes Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount Foreign withholding tax Deferred Tax Liabilities, Foreign Withholding Tax, Excluding Undistributed Foreign Earnings Deferred Tax Liabilities, Foreign Withholding Tax, Excluding Undistributed Foreign Earnings Restricted stock units released (in shares) Performance stock units released (in shares) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Released In Period The number of equity-based payment instruments, excluding stock options, that released during the reporting period. Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Retirement Plan Sponsor Location [Domain] Retirement Plan Sponsor Location [Domain] Accounts payable, accrued expenses and other Total Accounts Payable and Accrued Liabilities, Current Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Local Phone Number Local Phone Number Intangible assets, gross carrying amount Intangible Assets, Gross (Excluding Goodwill) Stockholders Equity [Line Items] Stockholders Equity [Line 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from acquisitions: Increase (Decrease) in Operating Capital [Abstract] Cumulative Effect, Period of Adoption [Domain] Cumulative Effect, Period of Adoption [Domain] Secured Overnight Financing Rate (SOFR) Secured Overnight Financing Rate (SOFR) [Member] PEO Total Compensation Amount PEO Total Compensation Amount Intersegment transfers in/(out) Goodwill, Transfers Federal Deferred Federal Income Tax Expense (Benefit) Restricted share grants, net settled shares (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Forfeited Property, Plant and Equipment, Type [Domain] Long-Lived Tangible Asset [Domain] Statement of Income Location, Balance [Axis] Statement of Income Location, Balance [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Forensic And Litigation Consulting FLC Forensic And Litigation Consulting [Member] Forensic And Litigation Consulting [Member] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Thereafter Finite-Lived Intangible Asset, Expected Amortization, after Year Five Debt Disclosure [Abstract] Debt Disclosure [Abstract] Common Stock Common Stock [Member] Measure: Measure [Axis] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Line of Credit Line of Credit [Member] Entity Emerging Growth Company Entity Emerging Growth Company Indefinite-lived Intangible Assets [Axis] Indefinite-Lived Intangible Assets [Axis] Other current liabilities Other Sundry Liabilities, Current Segment Reporting [Abstract] Segment Reporting [Abstract] Entity Central Index Key Entity Central Index Key Other segment items Segment Reporting, Other Segment Item, Amount Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Non-PEO NEO Average Compensation Actually Paid Amount 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Company Measurement Basis [Axis] Measurement Basis [Axis] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Title Trading Arrangement, Individual Title Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Economic Consulting Economic Consulting Economic Consulting Economic Consulting [Member] Economic Consulting [Member] Statement [Table] Statement [Table] Defined Contribution Plan [Table] Defined Contribution Plan [Table] Schedule of Components of Income Before Income Tax Provision from Continuing Operations Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Geographic Concentration Risk Geographic Concentration Risk [Member] Consolidation Items [Domain] Consolidation Items [Domain] City Area Code City Area Code Current liabilities Liabilities, Current [Abstract] Auditor Location Auditor Location Credit Facility [Member] Credit Facility [Member] Credit facility. Acquisition-related contingent consideration Business Combination, Contingent Consideration, Liability Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activities Notes granted Loans and Leases Receivable, Related Parties, Additions Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Cumulative translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Deferred compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits Total current assets Assets, Current Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Earnings Per Common Share [Line Items] Earnings Per Common Share [Line Items] Earnings Per Common Share [Line Items] Senior Notes Senior Notes [Member] All other foreign countries All other foreign countries All Other Countries [Member] All other countries. Purchase and retirement of common stock Payments for Repurchase of Common Stock Stock options outstanding and exercisable at end of period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Notes receivable from employees Deferred Tax Assets Notes Receivable From Employees Deferred tax assets notes receivable from employees. Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Federal Funds Federal Funds [Member] Federal Funds Weighted Average Grant Date Fair Value Weighted Average Grant Date Fair Value Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Income Taxes Income Tax Disclosure [Text Block] Purchase and retirement of common stock Total cost Stock Repurchased and Retired During Period, Value Liability for uncertain tax positions Liability for Uncertainty in Income Taxes, Noncurrent 2028 Lessee, Operating Lease, Liability, to be Paid, Year Four Earnings Per Share [Abstract] Earnings Per Share [Abstract] Equity [Abstract] Equity [Abstract] Retained earnings Retained Earnings (Accumulated Deficit) Schedule of Unvested Restricted Share Awards Activity Schedule of Nonvested Share Activity [Table Text Block] Purchase and retirement of common stock (in shares) Shares of common stock repurchased and retired (in shares) Stock Repurchased and Retired During Period, Shares Domestic Plan Domestic Plan [Member] Convertible Note Due 2023 Convertible Note Due 2023 [Member] Convertible Note Due 2023 [Member] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Equity Awards Adjustments Equity Awards Adjustments [Member] Weighted average discount rate, Operating leases Operating Lease, Weighted Average Discount Rate, Percent Total lease liabilities Total Operating Lease, Liability Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Underlying Securities Award Underlying Securities Amount Performance Stock Units Performance Stock Units Performance Shares [Member] Accounting Changes and Error Corrections [Abstract] Accounting Changes and Error Corrections [Abstract] Credit Facility [Axis] Credit Facility [Axis] Direct costs Direct Operating Costs Amendment Flag Amendment Flag Reported Value Measurement Reported Value Measurement [Member] Entity Registrant Name Entity Registrant Name Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Total segment gross profit Total segment gross profit Gross Profit Stock Options, 2022 Exercises Stock Options, 2022 Exercises [Member] Stock Options, 2022 Exercises Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Foreign currency translation adjustments, net of tax expense of $—, $— and $— Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent State Deferred State and Local Income Tax Expense (Benefit) Fair Value as of Grant Date Award Grant Date Fair Value Detriment from foreign tax rates Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount Subsequent Events [Abstract] Interest income and other Total Interest income and other Interest And Other Income Expense Net Interest and Other Income (Expense), Net Debt Debt Disclosure [Text Block] Audit Information [Abstract] Audit Information Operating lease liabilities DeferredTaxLiabilitiesOperatingLease DeferredTaxLiabilitiesOperatingLease Geographical [Domain] Geographical [Domain] Schedule of Other Intangible Assets Unamortized Intangibles Schedule of Indefinite-Lived Intangible Assets [Table Text Block] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Stock Options And Share-Based Awards Stock Options And Share-Based Awards [Member] Stock Options And Restricted Shares [Member] Issuance of common stock in connection with: Shares Granted or Issued, Share-Based Payment Arrangement [Abstract] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Advertising costs Advertising Expense Schedule of Share-Based Compensation Expense Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Restructuring Cost [Table] Restructuring Cost [Table] Technology Technology Technology Technology [Member] Technology [Member] Restatement Determination Date: Restatement Determination Date [Axis] Title of 12(b) Security Title of 12(b) Security Concentration Risk Type [Axis] Concentration Risk Type [Axis] Common stock, $0.01 par value; shares authorized — 75,000; shares issued and outstanding —35,913 (2024) and 35,521 (2023) Common Stock, Value, Issued Restructuring Charges, Statement of Income or Comprehensive Income [Extensible Enumeration] Restructuring Charges, Statement of Income or Comprehensive Income [Extensible Enumeration] Document Financial Statement Error Correction [Flag] Document Financial Statement Error Correction [Flag] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Share-Based Payment Arrangement [Abstract] Forgivable loans, forgiveness period, maximum Forgivable Loans Forgiveness Period Maximum Forgivable loans, forgiveness period, maximum Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Auditor Name Auditor Name Other, net Deferred Tax Assets, Other Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Schedule of Reconciliation of Net Income to Adjusted Segment Earnings before Interest, Taxes, Depreciation and Amortization Schedule Of Reconciliation Of Adjusted Segment E B I T D A Table [Table Text Block] Reconciliation of adjusted segment EBITDA to income before income tax provision. Restricted share awards forfeited (in dollars per share) Restricted stock units forfeited (in dollars per share) Performance stock units forfeited (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Current Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Preferred stock, $0.01 par value; shares authorized — 5,000; none    outstanding Preferred Stock, Value, Issued State income taxes, net of federal benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Estimated useful of furniture, equipment and internal use software Property, Plant and Equipment, Useful Life Options Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Total deferred tax liabilities Deferred Tax Liabilities, Gross Depreciation of property and equipment Depreciation, Depletion and Amortization, Nonproduction Fair Value Measurement [Domain] Fair Value Measurement [Domain] Earnings per common share — basic (in dollars per share) Earnings Per Share, Basic Cash paid for amounts included in the measurement of operating lease liabilities Operating Lease, Payments Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Schedule of Stock Repurchases Schedule Of Stock Repurchase [Table Text Block] Schedule Of Stock Repurchase Restricted Stock units and Performance Stock Units Restricted Stock And Performance Stock Units [Member] Restricted stock and performance stock units. Loans and Leases Receivable, Related Parties [Roll Forward] Loans and Leases Receivable, Related Parties [Roll Forward] Numerator — basic and diluted Earnings Per Share Basic And Diluted Numerator [Abstract] Earnings Per Share Basic And Diluted Numerator [Abstract] Concentrations of Risk Concentration Of Risk Policy [Policy Text Block] Concentration of risk policy. Non-cash additions to property and equipment Capital Expenditures Incurred but Not yet Paid Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Amortization of intangibles Amortization Goodwill [Table] Goodwill [Table] Net income Net Income (Loss) Available to Common Stockholders, Basic Property and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Stock, Class of Stock [Table] Stock, Class of Stock [Table] Total current liabilities Liabilities, Current Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Option, cost not yet recognized Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount Total assets Assets Notes outstanding (in notes) Number Of Notes Receivables Outstanding Number of Notes Receivables Outstanding 2025 Finite-Lived Intangible Asset, Expected Amortization, Year One Guarantor Obligation [Table] Guarantor Obligation [Table] Advertising Costs Advertising Cost [Policy Text Block] Restricted share awards granted (in shares) Restricted stock units granted (in shares) Performance stock units granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Income tax receivable Income Taxes Receivable, Current Purchases of property and equipment and other Payments to Acquire Property, Plant, and Equipment Other liabilities Other Liabilities, Noncurrent Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Cumulative Effect, Period of Adoption [Axis] Cumulative Effect, Period of Adoption [Axis] Commitments and contingencies (Note 16) Commitments and Contingencies Share-Based Compensation Share-Based Payment Arrangement [Policy Text Block] Acquisition-Related Contingent Consideration Business Combinations Policy [Policy Text Block] Schedule of Income Tax Provision from Continuing Operations Resulted in Effective Tax Rates Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Termination Date Trading Arrangement Termination Date Total revenues Revenues 2026 Lessee, Operating Lease, Liability, to be Paid, Year Two Share-Based Compensation Share-Based Payment Arrangement [Text Block] Entity Address, City or Town Entity Address, City or Town Effect of dilutive stock options (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements, Stock Options Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements, Stock Options Deferred tax assets Deferred Tax Assets, Gross [Abstract] Leases Lessee, Leases [Policy Text Block] Debt Instrument [Axis] Debt Instrument [Axis] Schedule of Stock Option Activity Share-Based Payment Arrangement, Option, Activity [Table Text Block] Intrinsic value of options exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Total share-based compensation expense Share-Based Payment Arrangement, Expense Net income Net income Net income Net Income (Loss) Attributable to Parent Trading Arrangement: Trading Arrangement [Axis] Settlement of conversion premium of convertible senior notes due 2023 Stock Issued During Period, Value, Conversion of Convertible Securities Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Restricted share awards forfeited (in shares) Performance stock units forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Schedule of Other Intangible Assets Amortized Intangibles Schedule of Finite-Lived Intangible Assets [Table Text Block] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Forgivable loans, forgiveness period, minimum Forgivable Loans Forgiveness Period Minimum Forgivable loans, forgiveness period, minimum Entity File Number Entity File Number Computer equipment and software Computer Equipment and Software [Member] Computer Equipment and Software [Member] Revenues Revenue from Contract with Customer [Text Block] Document Fiscal Year Focus Document Fiscal Year Focus Employee benefits obligations Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits Income Statement [Abstract] Income Statement [Abstract] Entity Address, Address Line One Entity Address, Address Line One Federal Current Federal Tax Expense (Benefit) Denominator Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Effect of exchange rate changes on cash and cash equivalents Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Continuing Operations 2016 Stock Repurchase Program Two Thousand Sixteen Stock Repurchase Program [Member] Two thousand sixteen stock repurchase program. Name Forgone Recovery, Individual Name Foreign Income (Loss) from Continuing Operations before Income Taxes, Foreign Stock options outstanding and exercisable, aggregate intrinsic value Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value Weighted average remaining lease term (years), Operating leases Operating Lease, Weighted Average Remaining Lease Term Award Date [Domain] Award Date [Domain] 2029 Finite-Lived Intangible Asset, Expected Amortization, Year Five Document Period End Date Document Period End Date Notes receivable, net Notes receivable from employees, net of current portion Financing Receivable, after Allowance for Credit Loss, Noncurrent Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Base Rate Base Rate [Member] Total future lease payments Lessee, Operating Lease, Liability, to be Paid Restricted share awards outstanding beginning of period (in shares) Restricted share awards outstanding ending of period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Insider Trading Arrangements [Line Items] Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment [Member] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Revenue recognition Deferred Tax Liabilities Revenue Recognition The tax effect as of the balance sheet date of the amount of estimated future taxable income arising from differences of the recognition of income for book and tax purposes related to receivables that are either subject to bankruptcy court approval or achieving a milestone. Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] U.S. foreign tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Foreign, Amount 2027 Lessee, Operating Lease, Liability, to be Paid, Year Three PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Direct cost of revenues Cost of Revenue Adjustment to Compensation: Adjustment to Compensation [Axis] Prepaid expenses and other current assets Total Prepaid Expense and Other Assets, Current Document Transition Report Document Transition Report Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Current Reporting Status Entity Current Reporting Status Retained Earnings Retained Earnings [Member] Accounts Receivable and Allowance for Expected Credit Losses Provision For Doubtful Accounts Disclosure [Text Block] Provision For Doubtful Accounts Disclosure Text Block Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Weighted average number of common shares outstanding — basic (in shares) Weighted Average Number of Shares Outstanding, Basic Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Restricted Stock Units Restricted Stock Units (RSUs) [Member] Amortization of debt issuance costs and other Amortization of Debt Issuance Costs and Discounts Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Executive Category: Executive Category [Axis] Name Awards Close in Time to MNPI Disclosures, Individual Name Construction in progress Construction in Progress [Member] Conversion of convertible senior notes due 2023 Adjustments to Additional Paid in Capital, Conversion of Convertible Senior Notes Adjustments to Additional Paid in Capital, Conversion of Convertible Senior Notes Consolidated Revenues Revenue Benchmark [Member] Schedule of Components of Income Tax Provision from Continuing Operations Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Entity Filer Category Entity Filer Category Unfulfilled performance obligations Revenue, Remaining Performance Obligation, Amount Statement of Income Location, Balance [Domain] Statement of Income Location, Balance [Domain] Effect of dilutive convertible notes (in shares) Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities Company Selected Measure Name Company Selected Measure Name