Revenue from providing access fees to customers for the use of electronic trading platform and revenue from telecommunication networks and communication services. Access and communication fees Accounts Payable, Current Accounts payable Accounts receivable, net of allowance of $1.9 and $1.8 Net accretion of discounts and amortization of premiums on marketable securities Net accretion of discounts and amortization of premiums on marketable securities Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss) Additional paid-in capital Amortization of shares issued to Board of Directors Tax benefit of stock issuance costs related to CBOT Holdings merger Tax benefit of stock issuance costs related to CBOT Holdings merger Excess tax benefits from option exercises and restricted stock vesting Adjustments to reconcile net income to net cash provided by operating activities: Accounts receivable, allowance Amendment Flag Net accretion of discounts and amortization of debt financing costs Amortization of purchased intangibles Total Assets Total Assets Assets Total current assets Total current assets Current Assets: Cash acquired in merger with CBOT Holdings Cash and cash equivalents Cash and Cash Equivalents, End of Period Cash and cash equivalents, beginning of period Net change in cash and cash equivalents Net change in cash and cash equivalents Cash Flow, Noncash Financing Activities Disclosure [Abstract] Non-cash financing activities: Cash Flow, Noncash Investing Disclosure [Abstract] Non-cash investing activities: The amount due to other broker-dealers in the form of a deposit paid by the counterparty to demonstrate an intention to complete a purchase (good faith deposit) and also the amount due to a customer in the form of collateral deposited by the counterparty to cover the credit risk assumed by the entity (margin deposit). Cash Performance Bonds and Security Deposit Liability Cash performance bonds and security deposits Class of Stock [Domain] Fees earned by providing executing servicing and clearing, net of rebates. Clearing and transaction fees COMMITMENTS Class A common stock Class A Common Stock (Shares) Common Class B, Class B-1 [Member] Class B common stock, Class B-1 Common Class B, Class B-2 [Member] Class B common stock, Class B-2 Common Class B, Class B-3 [Member] Class B common stock, Class B-3 Common Class B, Class B-4 [Member] Class B common stock, Class B-4 Class B common stock Class B Common Stock (Shares) Cash dividends on common stock, per share Common Stock and Additional Paid-in Capital Common stock, par value Common stock, shares authorized Common stock, shares issued Common stock, shares outstanding Common stock Communications Total comprehensive income Total comprehensive income Comprehensive income: Comprehensive Income Note [Text Block] ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Total Expenses Total Expenses Expenses Cumulative effect of adopting accounting guidance on uncertain tax positions Current Fiscal Year End Date DEBT Deferred income taxes Deferred tax liabilities, net Depreciation and amortization DERIVATIVE INSTRUMENTS STOCK-BASED PAYMENTS Cash dividend on common stock of $4.60 per share in 2009, $9.60 per share in 2008 and $3.44 per share in 2007 Cash dividend on common stock of $4.60 per share in 2009, $9.60 per share in 2008 and $3.44 per share in 2007 Document Information [Text Block] Document Period End Date Document Type Earnings per Common Share: Earnings Per Share, Basic Basic Earnings Per Share, Diluted Diluted EARNINGS PER SHARE Entity Central Index Key Entity Common Stock, Shares Outstanding Entity Current Reporting Status Entity [Domain] Entity Filer Category Entity Public Float Entity Registrant Name Entity [Text Block] Entity Voluntary Filers Entity Well-known Seasoned Issuer Equity Component [Domain] Excess tax benefits related to employee option exercises and restricted stock vesting FAIR VALUE MEASUREMENTS Fair value of Class A common stock and stock options issued in connection with CBOT Holdings merger Fair value of Class A common stock and stock options issued in connection with CBOT Holdings merger Fair value of Class A common stock, stock options and restricted stock units issued in connection with NYMEX Holdings merger Fair value of Class A common stock, stock options and restricted stock units issued in connection with NYMEX Holdings merger Gains (losses) on derivative investments Net loss on derivative investments Loss on sale of metals trading products Loss on sale of metals trading products Good Faith and Margin Deposits with Broker-Dealers Cash performance bonds and security deposits Goodwill INTANGIBLE ASSETS AND GOODWILL The charge against earnings resulting from the write down of available for sale security due to the difference between the carrying value and lower fair value. Impairment of securities lending assets Loss recognized during the period that results from the write-down of goodwill and intangibles after comparing the implied fair value of goodwill and intangible assets with the carrying amount of that goodwill and intangible assets. Impairment of goodwill and intangible assets Impairment of long-term investments Impairment of long-term investments Sum of operating profit and nonoperating income (expense) before income taxes. Income before Income Taxes Income before Income Taxes Equity in losses of unconsolidated subsidiaries Equity in losses of unconsolidated subsidiaries Income Statement [Abstract] INCOME TAXES Income taxes paid Income tax provision Increase (Decrease) in Accounts Payable Accounts payable Accounts receivable Accounts receivable Income tax payable Guarantee of exercise right privileges Guarantee of exercise right privileges Change in assets and liabilities: Increase (Decrease) in Other Accrued Liabilities Other current liabilities Increase (Decrease) in Other Operating Assets Other assets Increase (Decrease) in Other Operating Liabilities Other liabilities Increase (Decrease) in Prepaid, Deferred Expense and Other Assets Other current assets Technology support services Intangible assets-other, net Interest and other borrowing costs Interest and other borrowing costs Interest paid (excluding securities lending program) Investment income MARKETABLE SECURITIES Compensation and benefits Legal Entity [Axis] Total Liabilities Total Liabilities Total Liabilities and Shareholders' Equity Total Liabilities and Shareholders' Equity Liabilities and Shareholders' Equity Total current liabilities Total current liabilities Current Liabilities: Licensing and other fee agreements Marketable securities, including pledged securities of $- and $283.8 Fees earned by providing subscribers with market information such as current quotes, trade prices, volumes, etc. Quotation data fees Net Cash Provided by (Used in) Financing Activities Net Cash Provided by (Used in) Financing Activities Cash Flows from Financing Activities Net Cash Provided by (Used in) Investing Activities Net Cash Provided by (Used in) Investing Activities Cash Flows from Investing Activities Net Cash Provided by Operating Activities Net Cash Provided by Operating Activities Cash Flows from Operating Activities Net change in securities lending program liability. Net change in NYMEX securities lending program liabilities Net income Net Income Total Non-Operating Total Non-Operating Non-Operating Income (Expense) Notes to Financial Statements [Abstract] Notes to Financial Statements [Abstract] Payable under securities lending agreements Occupancy and building operations Operating Income Operating Income BUILDING TENANT LEASES Other Assets, Current Other current assets Other Assets disclosure. Other Assets Disclosure [Text Block] OTHER ASSETS Other Assets, Noncurrent Other assets Change in net unrealized securities gains (losses) Change in net actuarial loss on defined benefit plans, net of tax of $0.9 in 2009, $10.4 in 2008 and $1.6 in 2007 Change in net actuarial loss on defined benefit plans, tax Change in foreign currency translation adjustment, net of tax of $1.7 in 2009, $21.3 in 2008 and $0.3 in 2007 Change in foreign currency translation adjustment, tax Change in net unrealized derivatives gains (losses) Change in net unrealized gain (loss) on derivatives, net of tax of $4.7 in 2009 and $13.5 in 2008 Change in net unrealized gain (loss) on derivatives, tax Change in net unrealized gain (loss) on securities, net of tax of $16.5 in 2009, $16.4 in 2008 and $1.2 in 2007 Change in net unrealized gain (loss) on securities, tax Other Cost and Expense, Operating Other Other Current Assets Disclosure [Text Block] Other Current Assets Disclosure [Text Block] OTHER CURRENT ASSETS Other Current Liabilities Disclosure Other Current Liabilities Disclosure [Text Block] OTHER CURRENT LIABILITIES Intangible assets-trading products Disclosures regarding other investments. LONG-TERM INVESTMENTS Other Liabilities, Current Other current liabilities Other Liabilities Disclosure [Text Block] OTHER LIABILITIES Other Liabilities, Noncurrent Other liabilities Other income (expense) Other Sales Revenue, Net Other Parent Company [Member] Cash outflows from payment of membership rights. NYMEX membership rights payment NYMEX membership rights payment Merger-related transaction costs Merger-related transaction costs Purchase of derivative related to BM&FBOVESPA SA investment Purchase of derivative related to BM&FBOVESPA SA investment Net change in NYMEX securities lending program investments Net change in NYMEX securities lending program investments Contingent consideration for Liquidity Direct Technology, LLC assets Contingent consideration for Liquidity Direct Technology, LLC assets Repurchase of common stock, including costs Repurchase of common stock, including costs Cash dividends Cash dividends Stock issuance costs in mergers with NYMEX Holdings and CBOT Holdings Stock issuance costs in mergers with NYMEX Holdings and CBOT Holdings Purchases of available-for-sale marketable securities Purchases of available-for-sale marketable securities Acquisition of NYMEX Holdings, net of cash received Acquisition of NYMEX Holdings, net of cash received Acquisition of Credit Market Analysis Limited, net of cash received Acquisition of Credit Market Analysis Limited, net of cash received Capital contributions to FXMarketSpace Limited Capital contributions to FXMarketSpace Limited Purchases of property, net Purchases of property, net EMPLOYEE BENEFIT PLANS Disclosure of performance bonds and security deposits. PERFORMANCE BONDS AND SECURITY DEPOSITS Preferred stock Preferred stock, par value Preferred stock, shares authorized Preferred stock, issued Preferred stock, outstanding Preferred Stock, Value, Issued Preferred stock Proceeds from maturities of available-for-sale marketable securities Proceeds from other borrowings, net of issuance costs Proceeds (repayments) of commercial paper, net Proceeds from sale of metals trading products Proceeds from exercise of stock options Proceeds from Employee Stock Purchase Plan Processing Service Revenue (revenue from processing transactions conducted on other exchanges). Processing services Professional fees and outside services PROPERTY Property, net Allowance for doubtful accounts Cash outflows from purchase of exercise right privileges. Purchase of exercise right privileges Purchase of exercise right privileges QUARTERLY INFORMATION (UNAUDITED) Repayment of other borrowings Repayment of other borrowings Recognition of in-process research and development acquired from Credit Market Analysis Limited Restructuring and Related Activities Disclosure [Text Block] RESTRUCTURING Restructuring Charges Restructuring Retained Earnings (Accumulated Deficit) Retained earnings Retained Earnings Total Revenues Total Revenues Revenues