Document and Entity Information [Abstract] Document And Entity Information [Abstract] Statement [Table] Statement [Line Items] Document Type Amendment Flag Document Period End Date Document Fiscal Year Focus Document Fiscal Period Focus Trading Symbol Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Entity Filer Category Entity Common Stock, Shares Outstanding Entity Well-known Seasoned Issuer Entity Public Float Entity Current Reporting Status Entity Voluntary Filers Consolidated Balance Sheets [Abstract] Assets Current assets: Cash and cash equivalents Cash and cash equivalents at end of period Cash and cash equivalents at beginning of period Cash and Cash Equivalents, at Carrying Value, Total Restricted cash Restricted Cash and Investments, Noncurrent R Financial investments, at fair value Marketable Securities, Current, Total Receivables, net Receivables, Net, Current, Total Deferred tax assets Deferred Tax Assets, Net, Current, Ending Balance Deferred Tax Assets, Net, Current, Beginning Balance Deferred Tax Assets, Net, Current, Total Open Clearing Contracts Current Asset [Abstract] Open Clearing Contracts Current Asset [Abstract] Open clearing contracts: Through our clearing operations in the derivative markets with NASDAQ OMX Commodities and NASDAQ OMX Stockholm, we are the legal counterparty for each derivative position traded and thereby guarantee the fulfillment of each contract. We also act as the counterparty for certain trades on OTC derivative contracts. The derivatives are not used by NASDAQ OMX Commodities or NASDAQ OMX Stockholm for the purpose of trading on their own behalf. As the legal counterparty of each transaction, NASDAQ OMX Commodities and NASDAQ OMX Stockholm bear the counterparty risk between the purchaser and seller in the contract. The fair value of these derivative contracts with NASDAQ OMX Commodities and NASDAQ OMX Stockholm is reported gross in the Consolidated Balance Sheets as a receivable pertaining to the purchasing party and a payable pertaining to the selling party. Such receivables and payables attributable to outstanding derivative positions have been netted to the extent that such a legal offset right exists and, at the same time, that it is our intention to settle these items. Derivative Positions at Fair Value Assets Current Derivative positions, at fair value Derivative Assets, Total Through our clearing operations in the resale markets with NASDSQ OMX Stockholm, we are the legal counterparty for each resale contract traded and thereby guarantee the fulfillment of each contract. We only clear these transactions once a bilateral contract between members has been entered into whereby the two members have agreed on all terms in the transaction. The resale agreements are not used for financing purposes by NASDAQ OMX. We record resale agreements at the gross amount of the contract value plus interest in the Consolidated Balance Sheets as a receivable pertaining to the purchasing party. Such receivables attributable to outstanding resale agreements have been netted to the extent that such a legal offset right exists and, at the same time, that it is our intention to settle these items. Collateral for resale agreements are not held by NASDAQ OMX Stockholm. All resale clearing activities are transacted under our clearing member agreements that give us the right, in the event of default, to liquidate collateral pledged between the clearing members and to offset receivables and payables with the same counterparty. Resale Agreements At Contract Value Resale agreements, at contract value Other current assets Total current assets Total current assets Non-current restricted cash Restricted Cash and Investments, Noncurrent Non-current restricted cash PropertyPlantAndEquipmentNet Property, Plant and Equipment, Net, Ending Balance Property, Plant and Equipment, Net, Beginning Balance Property and equipment, net Total property and equipment, net Purchases of property and equipment Non-current deferred tax assets Deferred Tax Assets, Net, Noncurrent, Total Goodwill Balance at December 31, 2011 Balance at December 31, 2010 Balance at December 31, 2009 Goodwill, Total Intangible assets, net Total intangible assets Intangible Assets, Net (Excluding Goodwill), Total Total intangible assets, Net Assets Other assets Other Assets, Noncurrent, Total Other non-current assets Total assets Total assets Liabilities Current liabilities: Accounts Payable and Accrued Liabilities, Current Accounts Payable and Accrued Liabilities, Current, Total Accounts payable and accrued expenses We pay Section 31 fees to the SEC for supervision and regulation of securities markets. The amount due to the SEC is remitted semiannually and recorded as Section 31 fees payable to the SEC. Section 31 fees payable Section 31 fees payable to SEC Employee-related Liabilities, Current Employee-related Liabilities, Current, Total Accrued personnel costs Deferred Revenue, Current Deferred Revenue, Current, Total Deferred revenue Other Liabilities, Current Other Liabilities, Current, Total Other current liabilities Deferred Tax Liabilities Current Business Acquisition Current Deferred Tax Liability Deferred tax liabilities Open Clearing Contracts Current Liabilities [Abstract] Open Clearing Contracts Current Liabilities [Abstract] Open clearing contracts: Through our clearing operations in the derivative markets with NASDAQ OMX Commodities and NASDAQ OMX Stockholm, we are the legal counterparty for each derivative position traded and thereby guarantee the fulfillment of each contract. We also act as the counterparty for certain trades on OTC derivative contracts. The derivatives are not used by NASDAQ OMX Commodities or NASDAQ OMX Stockholm for the purpose of trading on their own behalf. As the legal counterparty of each transaction, NASDAQ OMX Commodities and NASDAQ OMX Stockholm bear the counterparty risk between the purchaser and seller in the contract. The fair value of these derivative contracts with NASDAQ OMX Commodities and NASDAQ OMX Stockholm is reported gross in the Consolidated Balance Sheets as a receivable pertaining to the purchasing party and a payable pertaining to the selling party. Such receivables and payables attributable to outstanding derivative positions have been netted to the extent that such a legal offset right exists and, at the same time, that it is our intention to settle these items. Derivative Positions at Fair Value Liabilities Current Derivative positions, at fair value Derivative positions, at fair value Through our clearing operations in the resale markets with NASDSQ OMX Stockholm, we are the legal counterparty for each repurchase contract traded and thereby guarantee the fulfillment of each contract. We only clear these transactions once a bilateral contract between members has been entered into whereby the two members have agreed on all terms in the transaction. The repurchase agreements are not used for financing purposes by NASDAQ OMX. We record repurchase agreements at the gross amount of the contract value plus interest in the Consolidated Balance Sheets as a payable pertaining to the selling party. Such liabilities attributable to outstanding repurchase agreements have been netted to the extent that such a legal offset right exists and, at the same time, that it is our intention to settle these items. Collateral for repurchase agreements are not held by NASDAQ OMX Stockholm. All repurchase clearing activities are transacted under our clearing member agreements that give us the right, in the event of default, to liquidate collateral pledged between the clearing members and to offset receivables and payables with the same counterparty. Repurchase Agreements At Contract Value Repurchase agreements, at contract value Current portion of debt obligations Less current portion Less current portion Less current portion Long-term Debt, Current Maturities, Total Total current liabilities Total current liabilities Long-term Debt, Excluding Current Maturities Total long-term debt obligations ending balance Total long-term debt obligations beginning balance Debt obligations Debt obligations Non-current deferred tax liabilities Non-current deferred revenue Deferred Revenue, Noncurrent, Total Other Liabilities, Noncurrent Other non-current liabilities Other Liabilities, Noncurrent, Total Other liabilities Total liabilities Total liabilities Commitments and contingencies Equity Commitments and contingencies Equity NASDAQ OMX stockholders' equity: Common stock, $0.01 par value, 300,000,000 shares authorized, shares issued: 213,370,086 at December 31, 2010 and 211,713,186 at December 31, 2009; shares outstanding: 175,782,683 at December 31, 2010 and 211,385,464 at December 31, 2009 Common Stock, Value, Issued, Ending Balance Common Stock, Value, Issued, Beginning Balance Common stock, $0.01 par value, 300,000,000 shares authorized, shares issued: 212,993,586 at September 30, 2010 and 211,713,186 at December 31, 2009; shares outstanding: 197,826,542 at September 30, 2010 and 211,385,464 at December 31, 2009 Common Stock, Value, Issued, Total Common stock, $0.01 par value, 300,000,000 shares authorized, shares issued: 213,398,111 at December 31, 2011 and 213,370,086 at December 31, 2010; shares outstanding: 173,552,939 at December 31, 2011 and 175,782,683 at December 31, 2010 Preferred stock, 30,000,000 shares authorized, series A convertible preferred stock: shares issued: 1,600,000 at December 31, 2010 and December 31, 2009; shares outstanding: none at December 31, 2010 and 1,600,000 at December 31, 2009 (classified above at December 31, 2009 as temporary equity) Preferred stock, 30,000,000 shares authorized, series A convertible preferred stock: shares issued: 1,600,000 at September 30, 2010 and December 31, 2009; shares outstanding: none at September 30, 2010 and 1,600,000 at December 31, 2009 (classified above at December 31, 2009 as temporary equity) Balance as of September 30, 2010 Balance as of December 31, 2009 Preferred stock, 30,000,000 shares authorized, series A convertible preferred stock: shares issued: 1,600,000 at December 31, 2011 and December 31, 2010; shares outstanding: none at December 31, 2011 and December 31, 2010 Preferred Stock, Value, Issued, Total Series A convertible preferred stock Additional paid-in capital Additional Paid in Capital, Ending Balance Additional Paid in Capital, Beginning Balance Additional Paid in Capital, Total Common stock in treasury, at cost: 37,587,403 shares at December 31, 2010 and 327,722 shares at December 31, 2009 Common stock in treasury, at cost: 39,845,172 shares at December 31, 2011 and 37,587,403 shares at December 31, 2010 Common stock in treasury, at cost: 15,167,044 shares at September 30, 2010 and 327,722 shares at December 31, 2009 Treasury Stock, Value, Ending Balance Treasury Stock, Value, Beginning Balance Common stock in treasury, at cost: 37,076,791 shares at March 31, 2011 and 37,587,403 shares at December 31, 2010 Aggregate purchase price Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance Accumulated Other Comprehensive Income (Loss), Net of Tax, Total Accumulated Other Comprehensive Loss, Net balance Retained earnings Retained Earnings (Accumulated Deficit), Ending Balance Retained Earnings (Accumulated Deficit), Beginning Balance Retained Earnings (Accumulated Deficit), Total Total NASDAQ OMX stockholders' equity Stockholders' Equity Attributable to Parent, Ending Balance Stockholders' Equity Attributable to Parent, Beginning Balance Total NASDAQ OMX stockholders' equity Noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest, Ending Balance Stockholders' Equity Attributable to Noncontrolling Interest, Beginning Balance Stockholders' Equity Attributable to Noncontrolling Interest, Total Total equity Balance Balance Total equity Total liabilities, series A convertible preferred stock and equity Total liabilities and equity Total liabilities and equity Common stock, par value Common stock value per share Common stock, shares authorized Common stock, shares issued Common Stock, Shares, Issued, Total Common stock Common stock, shares outstanding Common Stock, Shares, Outstanding, Ending Balance Common Stock, Shares, Outstanding, Beginning Balance Preferred stock, shares authorized Preferred stock, series A convertible preferred stock: shares issued Preferred Stock, Shares Issued, Total Preferred stock, series A convertible preferred stock: shares outstanding Preferred Stock, Shares Outstanding, Ending Balance Preferred Stock, Shares Outstanding, Beginning Balance Common stock in treasury, shares Share repurchase program (in shares) Treasury Stock, Shares, Ending Balance Treasury Stock, Shares, Beginning Balance Share repurchase program (in shares) Consolidated Statements Of Income [Abstract] Revenues: Total revenues Total revenues Total revenues Cost of revenues: Transaction Rebates Transaction Rebates Transaction rebates Brokerage, clearance and exchange fees Brokerage, clearance and exchange fees Floor Brokerage, Exchange and Clearance Fees, Total Total cost of revenues Cost of revenues Total cost of revenues Cost of Revenue, Total Cost of revenues Revenues less transaction rebates, brokerage, clearance and exchange fees Revenues less transaction rebates, brokerage, clearance and exchange fees Revenues less transaction rebates, brokerage, clearance and exchange fees Operating expenses: Compensation and benefits Labor and Related Expense, Total Marketing and advertising Marketing and Advertising Expense, Total Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction, Total Professional and contract services Computer operations and data communications Communications and Information Technology, Total Occupancy Regulatory expense includes cost incurred during the period associated with regulation of trading activity and the surveillance and investigation functions of NASDAQ OMX. Regulatory Operating Expense Regulatory Merger expenses Merger and strategic initiatives General, administrative and other General and Administrative Expense, Total Total operating expenses Total operating expenses Operating income Operating income Interest income Interest Expense Interest expense Net interest expense Interest Expense, Total Net income expense Dividend and investment income Investment Income, Net, Total Equity Method Investment, Other than Temporary Impairment Asset impairment charge Non-cash impairment charge included in asset impairment charge Other-than-temporary impairment loss on investment security Loss on divestiture of businesses Loss on divestiture of businesses Loss on divestiture of businesses Gain (Loss) on Sale of Securities, Net, Total Loss on the sale Income from unconsolidated investees, net Net (income) loss from unconsolidated investees Equity method investment, income (loss) Income (loss) from unconsolidated investees, net Income (Loss) from Equity Method Investments, Total Income (loss) from equity method investments Loss on sale of investment security Loss on sale of investment security Loss on sale of investment security Gain (Loss) on Sale of Securities, Net, Total Loss on sale of investment security Gain on sales of businesses Gain On Sales Of Businesses Gain on sales of businesses Gain on sales of businesses Gain on sales of businesses Debt conversion expense Debt conversion expense Debt conversion expense Amortization of debt issuance costs Income Loss From Continuing Operations Before Income Taxes Income (loss) before income taxes Income before income taxes Income before income taxes Income Tax Expense Benefit Income tax (expense) benefit Income tax benefits Income tax provision Total income tax provision Income tax expense Profit Loss Net income Net income Net income Net income Net income (loss) Net (income) loss attributable to noncontrolling interests Net loss attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest, Total Net income attributable to NASDAQ OMX Net income attributable to NASDAQ OMX Basic and diluted earnings per share: Basic earnings per share Earnings Per Share, Basic, Total Diluted earnings per share Earnings Per Share, Diluted, Total Consolidated Statements Of Comprehensive Income [Abstract] Other comprehensive income (loss): Net unrealized holding losses on available-for-sale investment securities: Net unrealized holding losses on available-for-sale investment securities: Unrealized holding gains (losses) arising during the period Unrealized holding losses arising during the period Unrealized holding gains (losses) arising during the period Unrealized holding losses arising during the period Unrealized holding loss in accumulated other comprehensive loss Other Comprehensive Income, Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax Income tax benefit Net unrealized holding gains (losses) on available-for-sale securities, tax Income tax benefit, net of valuation allowance Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Net of Tax Reclassification adjustment for losses realized in net income on available-for-sale investment securities Other Comprehensive Income, Available-for-sale Securities Adjustment, Net of Tax Total Total Foreign currency translation gains (losses): Net foreign currency translation gains Other Comprehensive Income, Foreign Currency Transaction and Translation Adjustment, before Tax, Total Net foreign currency translation gains (losses) Income tax (expense) benefit Foreign currency translation, tax Foreign currency translation, net of tax Other Comprehensive Income, Foreign Currency Translation Adjustment, Tax, Total Foreign currency translation, tax Other Comprehensive Income, Foreign Currency Transaction and Translation Adjustment, Net of Tax Foreign currency translation, net of tax Total Unrealized gains (losses) on cash flow hedges: Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax Unrealized gains on cash flow hedges arising during the period Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax Change in unrealized losses on derivative financial instruments that qualify as cash flow hedges, tax Income tax expense Reclassification adjustment for loss realized in net income on cash flow hedges Reclassification adjustment for loss realized in net income on cash flow hedges Income tax benefit recognized in net income during the period Reclassification adjustment for loss realized in net income on cash flow hedges, tax Total Change in unrealized losses on derivative financial instruments that qualify as cash flow hedges, net of tax Total Employee benefit plans: Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax Employee benefit plan adjustments, net of tax Employee benefit plan adjustment losses Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, Total Total Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax Income tax benefit Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax, Total Employee benefit plan adjustments, tax Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax Employee benefit plan adjustments, net of tax Total Employee benefit plan adjustments, net of tax Total other comprehensive income, net of taxes Total other comprehensive income (loss), net of tax Comprehensive income Comprehensive income Comprehensive income (loss) Comprehensive (income) loss attributable to noncontrolling interests Comprehensive loss attributable to noncontrolling interests Comprehensive Income, Net of Tax, Attributable to Noncontrolling Interest, Total Comprehensive income (loss) attributable to NASDAQ OMX Comprehensive income attributable to NASDAQ OMX Comprehensive income attributable to NASDAQ OMX Consolidated Statements Of Changes In Equity [Abstract] Statement, Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Parent [Member] Parent [Member] Common Stock [Member] Common Stock [Member] Additional Paid In Capital [Member] Additional Paid-In Capital [Member] Treasury Stock [Member] Common Stock In Treasury At Cost [Member] Accumulated Other Comprehensive Income [Member] Accumulated Other Comprehensive Loss [Member] Retained Earnings [Member] Retained Earnings [Member] Noncontrolling Interest [Member] Noncontrolling Interests [Member] Shares, Issued Balance (in shares) Balance (in shares) Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax Reclassification adjustment for loss realized in net income on cash flow hedges, net of tax Reclassification adjustment for loss realized in net income on cash flow hedges, net of tax Reclassification adjustment for loss realized in net income on cash flow hedges, net of tax Stock Issued During Period, Value, Conversion of Convertible Securities Conversion into common stock Conversion into common stock Stock Issued During Period, Shares, Conversion of Convertible Securities Conversion of Convertible Securities (in shares) Issuance of shares of common stock Early Repayment of Senior Debt Early extinguishment of a portion of the 2013 Convertible Notes Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Amortization and vesting of restricted stock and PSUs Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures, Total Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Restricted stock awards issued Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures, Total Amortization and vesting of restricted stock and PSUs (in shares) Stock Issued During Period, Value, Stock Options Exercised Stock options exercised, net Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Stock Options, Exercised Stock Options, Exercises Stock options exercised, net (in shares) Other purchases of common stock net value Other Purchases Of Common Stock Net Value Other issuances of common stock, net Other purchases of common stock net in shares Other Purchases Of Common Stock Net In Shares Other issuances of common stock, net (in shares) Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Purchases of subsidiary shares from noncontrolling interests Purchases of subsidiary shares from noncontrolling interests Noncontrolling Interest, Increase from Equity Issuance or Sale of Parent Equity Interest Sale of subsidiary shares to noncontrolling interests and other adjustments Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss), Net of Tax Unrealized holding losses on available-for-sale securities, net Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss), Net of Tax, Total Adjustments to Additional Paid in Capital, Convertible Debt with Conversion Feature Tender offer related to the 2013 Convertible Notes Treasury Stock, Value, Acquired, Par Value Method Share repurchase program Share repurchase program Conversion Of Convertible Notes Conversion Of Convertible Notes Conversion of convertible notes Consolidated Statements Of Cash Flows [Abstract] Cash flows from operating activities: Adjustments to reconcile net income to cash provided by operating activities: Share based compensation Share-based compensation Share-based Compensation, Total Excess Tax Benefit from Share-based Compensation, Operating Activities Excess tax benefits related to share-based compensation Provision for bad debts Write off of deferred debt issuance cost Repayments of secured debt Charges related to debt extinguishment and refinancing Gains (Losses) on Extinguishment of Debt Gain on the early extinguishment of debt obligations Gain on the early extinguishment of debt obligations Gains (Losses) on Extinguishment of Debt, Total Pre-tax gain on early extinguishment of debt Deferred taxes, net Total deferred income taxes Deferred income taxes Asset retirements Asset impairment charge Asset retirements and impairment charges Asset Impairment Charges, Total Equity method investment impairment charges Amortization of financing costs and discounts Amortization of debt issuance costs Amortization of Financing Costs and Discounts, Total Amortization expense for debt issuance costs Amortization of Debt Discount (Premium) Accretion of debt discounts Other non-cash items included in net income Other non-cash items included in net income Other Noncash Income (Expense), Total Net change in operating assets and liabilities, net of effects of acquisitions and divestitures: Increase (Decrease) in Receivables Receivables, net Increase (Decrease) in Receivables, Total Increase (Decrease) in Other Operating Assets Other assets Increase (Decrease) in Other Operating Assets, Total Increase (Decrease) in Accounts Payable and Accrued Liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities, Total Accounts payable and accrued expenses Increase (Decrease) in Other Accounts Payable Section 31 fees payable to SEC Increase (Decrease) in Employee Related Liabilities Increase (Decrease) in Employee Related Liabilities, Total Accrued personnel costs Increase (Decrease) in Deferred Revenue Deferred revenue Increase (Decrease) in Other Operating Liabilities Other non-current liabilities Increase (Decrease) in Other Operating Liabilities, Total Other liabilities Cash provided by operating activities Net cash provided by operating activities Net cash provided by (used in) operating activities Cash flows from investing activities: Purchases of trading securities Purchases of trading securities Payments to Acquire Equity Method Investments Purchase of equity method investment Purchase of equity method investment Proceeds from sales and redemptions of trading securities Proceeds from Sale and Maturity of Marketable Securities, Total Proceeds from Sale of Available-for-sale Securities Proceeds from sales and redemptions of available-for-sale investment securities Proceeds from Sale of Available-for-sale Securities, Total Proceeds from sales of equity method investments Proceeds from sales of equity method investments Acquisitions of businesses, net of cash and cash equivalents acquired and purchase accounting adjustments Acquisitions of businesses, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired, Total