CME (CME) 10-K 26 Feb 16 2015 FY Annual report Financial data

DEI Statement

DEI Statement - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2015	Feb. 10, 2016	Jun. 30, 2015
Entity Information [Line Items]
Entity Registrant Name	CME GROUP INC.
Entity Central Index Key	1,156,375
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 31.1
Class B Common Stock, Class B1 [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		625
Class B Common Stock, Class B2 [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		813
Class B Common Stock, Class B3 [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		1,287
Class B Common Stock, Class B4 [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		413
Class A Common Stock (Shares) [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		338,412,729

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents		$ 1,692.6	$ 1,366.1
Marketable securities		72.5	74.7
Accounts receivable, net of allowance		357.8	341.2
Other current assets		228.6	196.5
Cash performance bonds and guaranty fund contributions		35,553	40,566.8
Total current assets		37,904.5	42,545.3
Property, net of accumulated depreciation and amortization		491.7	508.9
Intangible assets-trading products	[1]	17,175.3	17,175.3
Intangible assets-other, net		2,537.9	2,637.4
Goodwill		7,569	7,569
Other assets		1,693.1	1,805.6
Total Assets		67,371.5	72,241.5
Liabilities and Shareholders' Equity
Accounts payable		28.7	36.9
Other current liabilities		1,242.8	927.5
Cash performance bonds and guaranty fund contributions		35,553	40,566.8
Total current liabilities		36,824.5	41,531.2
Long-term debt		2,241.4	2,107.9
Deferred Tax Liabilities, Net, Noncurrent		7,358.3	7,302.7
Other liabilities		395.5	376.2
Total Liabilities		46,819.7	51,318
Shareholders' Equity:
Preferred stock, $0.01 par value, 10,000 shares authorized, none issued or outstanding		0	0
Additional paid-in capital		17,721.6	17,596.6
Retained earnings		2,907.6	3,317.3
Accumulated other comprehensive income (loss)		(80.8)	6.2
Total Shareholders' Equity		20,551.8	20,923.5
Total Equity		20,551.8	20,923.5
Total Liabilities and Shareholders' Equity		67,371.5	72,241.5
Class A Common Stock (Shares) [Member]
Shareholders' Equity:
Common stock		3.4	3.4
Class B Common Stock (Shares) [Member]
Shareholders' Equity:
Common stock		$ 0	$ 0
[1]	(1)Trading products represent futures and options products acquired in our business combinations with CBOT Holdings, Inc., NYMEX Holdings, Inc. and KCBT. Clearing and transaction fees are generated through the trading of these products. These trading products, most of which have traded for decades, require authorization from the CFTC. Product authorizations from the CFTC have no term limits.

CONSOLIDATED BALANCE SHEETS Bal

CONSOLIDATED BALANCE SHEETS Balance Sheet Parenthicals - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Allowance for Doubtful Accounts Receivable	$ 1.9	$ 1.2
Restricted Cash and Cash Equivalents, Current	32	37
Restricted Cash and Cash Equivalents, Noncurrent	$ 70.5	$ 72.4
Series A junior participating preferred stock [Member]
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	10,000,000	10,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Series B Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share	$ 0	$ 0
Preferred Stock, Shares Authorized	0	0
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Class A Common Stock (Shares) [Member]
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	1,000,000,000	1,000,000,000
Common Stock, Shares, Outstanding	336,938,000	335,452,000
Common Stock, Shares, Issued	336,938,000	335,452,000
Class B Common Stock (Shares) [Member]
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	3,000	3,000
Common Stock, Shares, Outstanding	3,000	3,000
Common Stock, Shares, Issued	3,000	3,000

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues
Clearing and transaction fees	$ 2,783.9	$ 2,616.3	$ 2,460.4
Market data and information services	399.4	356.3	315.4
Access and communication fees	86.1	82.7	83.2
Other	57.4	57.2	77.3
Total Revenues	3,326.8	3,112.5	2,936.3
Expenses
Compensation and benefits	553.7	552.1	518.9
Communications	27.8	32	35.3
Technology support services	64.5	58.2	53.6
Professional fees and outside services	122.8	129	130.3
Amortization of purchased intangibles	99.4	100.6	103
Depreciation and amortization	129.2	132.6	135.1
Occupancy and building operations	92.5	96.8	78.3
Licensing and other fee agreements	123.8	114.2	97.9
Other	124.4	128.6	146.9
Total Expenses	1,338.1	1,344.1	1,299.3
Operating Income	1,988.7	1,768.4	1,637
Non-Operating Income (Expense)
Investment income	30.1	35.8	44.9
Gains (losses) on derivative investments	(1.8)	0	0
Interest and other borrowing costs	(117.4)	(119.4)	(151.4)
Equity in net (gains) losses of unconsolidated subsidiaries	100	84.8	70.5
Other income (expense)	(42.8)	1.8	0
Total Non-Operating	(31.9)	3	(36)
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	1,956.8	1,771.4	1,601
Income tax provision	709.8	644.5	622.9
Net Income	1,247	1,126.9	978.1
Net Income (Loss) Attributable to Noncontrolling Interest	0	(0.2)	1.3
Net Income Attributable to CME Group	$ 1,247	$ 1,127.1	$ 976.8
Earnings per Common Share Attributable to CME Group:
Basic	$ 3.71	$ 3.37	$ 2.94
Diluted	$ 3.69	$ 3.35	$ 2.92
Weighted Average Number of Common Shares:
Basic	336,224	334,409	332,678
Diluted	337,894	336,063	334,398

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net income	$ 1,247	$ 1,126.9	$ 978.1
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax	(78)	(116.6)	(221)
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, before Tax	8.5	0	(0.7)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	(2.6)	(5.2)	63.9
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	(72.1)	(121.8)	(157.8)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax	(11.2)	(30)	28.4
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, before Tax	2.7	0.3	3.2
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax	3.2	11.2	(12)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(5.3)	(18.5)	19.6
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	(4.7)	(2.3)	128.8
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax	(1.2)	(1.5)	1.6
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	1.1	1.4	(49)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(3)	(2.4)	81.4
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	(10.6)	(5.2)	(0.8)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	4	2.1	0.3
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(6.6)	(3.1)	(0.5)
Other Comprehensive Income (Loss), Net of Tax	(87)	(145.8)	(57.3)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	1,160	981.1	920.8
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	0	(0.2)	1.3
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 1,160	$ 981.3	$ 919.5

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock and Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Parent [Member]	Noncontrolling Interest [Member]	Class A Common Stock (Shares) [Member]	Class B Common Stock (Shares) [Member]
Beginning Balance (in shares) at Dec. 31, 2012							331,832,000	3,000
Total Equity Beginning Balance at Dec. 31, 2012	$ 21,424.9	$ 17,216.4	$ 3,993.4	$ 209.3	$ 21,419.1	$ 5.8
Comprehensive income:
Net income attributable to CME Group	976.8		976.8		976.8
Net Income (Loss) Attributable to Noncontrolling Interest						(0.1)
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	976.7
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(57.3)			(57.3)	(57.3)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	19.6
Total comprehensive income attributable to CME Group	919.5
Dividends, Cash	1,475.6		1,475.6		1,475.6
Adjustments to Additional Paid in Capital, Other	167.9	167.9			167.9
Exercise of stock options (in shares)							1,532,000
Exercise of stock options	73.7	73.7			73.7
Excess tax benefits from option exercises and restricted stock vesting	6.8	6.8			6.8
Stock Issued During Period, Shares, Restricted Stock Award, Gross							442,000
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	14.4	14.4			14.4
Shares issued to Board of Directors (in shares)							27,000
Stock Issued to Board of Directors, Value, Issued for Services	2.1	2.1			2.1
Shares issued under Employee Stock Purchase Plan (in shares)							19,000
Shares issued under Employee Stock Purchase Plan	1.3	1.3			1.3
Stock-based compensation	54.4	54.4			54.4
Ending Balance (in shares) at Dec. 31, 2013							333,852,000	3,000
Total Equity Ending Balance at Dec. 31, 2013	21,160.5	17,508.2	3,494.6	152	21,154.8	5.7
Comprehensive income:
Net income attributable to CME Group	1,127.1				1,127.1
Net Income (Loss) Attributable to Noncontrolling Interest						(0.2)
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	1,126.9
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(145.8)			(145.8)	(145.8)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(18.5)
Total comprehensive income attributable to CME Group	981.3
Dividends, Cash	1,304.4		1,304.4		1,304.4
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests						(5.5)
Adjustments to Additional Paid in Capital, Other	(13.3)	(7.8)			(7.8)
Exercise of stock options (in shares)							1,031,000
Exercise of stock options	53.3	53.3			53.3
Excess tax benefits from option exercises and restricted stock vesting	4	4			4
Stock Issued During Period, Shares, Restricted Stock Award, Gross							511,000
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	16.7	16.7			16.7
Shares issued to Board of Directors (in shares)							34,000
Stock Issued to Board of Directors, Value, Issued for Services	2.4	2.4			2.4
Shares issued under Employee Stock Purchase Plan (in shares)							24,000
Shares issued under Employee Stock Purchase Plan	1.8	1.8			1.8
Stock-based compensation	54.8	54.8			54.8
Ending Balance (in shares) at Dec. 31, 2014							335,452,000	3,000
Total Equity Ending Balance at Dec. 31, 2014	20,923.5	17,600	3,317.3	6.2	$ 20,923.5	$ 0
Comprehensive income:
Net income attributable to CME Group	1,247
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(87)			(87)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(5.3)
Total comprehensive income attributable to CME Group	1,160
Dividends, Cash	1,656.7		1,656.7
Adjustments to Additional Paid in Capital, Other	$ 9.3	9.3
Exercise of stock options (in shares)	984,581						984,000
Exercise of stock options	$ 64	64
Excess tax benefits from option exercises and restricted stock vesting	3.8	3.8
Stock Issued During Period, Shares, Restricted Stock Award, Gross							456,000
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	17.2	17.2
Shares issued to Board of Directors (in shares)							26,000
Stock Issued to Board of Directors, Value, Issued for Services	2.4	2.4
Shares issued under Employee Stock Purchase Plan (in shares)							20,000
Shares issued under Employee Stock Purchase Plan	1.9	1.9
Stock-based compensation	60.8	60.8
Ending Balance (in shares) at Dec. 31, 2015							336,938,000	3,000
Total Equity Ending Balance at Dec. 31, 2015	$ 20,551.8	$ 17,725	$ 2,907.6	$ (80.8)

CONSOLIDATED STATEMENTS OF SHA7

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY Equity Statement Parentheticals - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Stockholders' Equity Parentheticals [Abstract]
Common Stock, Dividends, Per Share, Declared	$ 4.90	$ 3.88	$ 4.40

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash Flows from Operating Activities
Net income	$ 1,247	$ 1,126.9	$ 978.1
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation	60.8	54.8	54.4
Amortization of purchased intangibles	99.4	100.6	103
Depreciation and amortization	129.2	132.6	135.1
Gain (Loss) on Sale of Securities, Net	8.5	0	0
Gains (Losses) on Extinguishment of Debt	61.8	0	0
Gain (Loss) on Sale of Property Plant Equipment	0	0	27.1
Income (Loss) from Equity Method Investments, Net of Dividends or Distributions	(5.1)	(8.6)	(2)
Deferred income taxes	63.3	78.9	(6)
Change in assets and liabilities:
Accounts receivable	(17.3)	(38.5)	(35.5)
Other current assets	(12.7)	3.7	(2.6)
Other assets	(4)	(11.5)	0.6
Accounts payable	(8.2)	0.7	(5.5)
Income tax payable	(82.1)	(105.6)	(9.3)
Other current liabilities	(21.1)	(46.1)	42.5
Other liabilities	(9.8)	(2.8)	(5.5)
Other	5.6	6.3	6.1
Net Cash Provided by Operating Activities	1,515.3	1,291.4	1,280.5
Cash Flows from Investing Activities
Proceeds from maturities of available-for-sale marketable securities	38.3	37.5	36.5
Purchases of available-for-sale marketable securities	(35.3)	(38.3)	(36.6)
Purchases of property, net	(114.2)	(140.7)	(125.6)
Proceeds from sale of building property	0	7.9	192.4
Investments in business ventures	(16.7)	(65.5)	(4)
Proceeds from Sale of Available-for-sale Securities, Equity	138.8	0	0
Settlement of derivative related to debt issuance	7	0	127.8
Net Cash Provided by (Used in) Investing Activities	17.9	(199.1)	190.5
Cash Flows from Financing Activities
Proceeds from other borrowings, net of issuance costs	743.7	0	748.7
Repayment of other borrowings	(673)	(750)	(750)
Cash dividends	(1,343.4)	(1,496.8)	(599.1)
Proceeds from exercise of stock options	64	53.3	73.7
Distribution paid to non-controlling interest	0	(4.7)	(80)
Excess tax benefits related to employee option exercises and restricted stock vesting	7.1	4	6.8
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	(7)	(3.6)	(7.3)
Other	1.9	1.9	1.2
Net Cash Provided by (Used in) Financing Activities	(1,206.7)	(2,195.9)	(606)
Net change in cash and cash equivalents	326.5	(1,103.6)	865
Cash and cash equivalents, beginning of period	1,366.1	2,469.7	1,604.7
Cash and Cash Equivalents, End of Period	1,692.6	1,366.1	2,469.7
Supplemental Disclosure of Cash Flow Information
Income taxes paid	716.6	641.5	612.2
Interest paid (excluding securities lending program)	89.1	111.4	133.4
Non-cash financing activities:
dividends declared	$ 977.1	$ 670.9	$ 868

Organization and Business

Organization and Business	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Business	ORGANIZATION AND BUSINESS Chicago Mercantile Exchange Inc. (CME), the Board of Trade of the City of Chicago, Inc. (CBOT), New York Mercantile Exchange, Inc. (NYMEX) and Commodity Exchange, Inc. (COMEX), wholly-owned subsidiaries of CME Group Inc. (CME Group), are designated contract markets for the trading of futures and options on futures contracts. CME, CBOT, NYMEX, COMEX, CME Clearing Europe Limited (CMECE) and CME Europe Limited (CME Europe) and their subsidiaries are referred to collectively as “the exchange” in the notes to the consolidated financial statements. CME Group and its subsidiaries are referred to collectively as “the company” in the notes to the consolidated financial statements. CME Group offers a wide range of products for trading and/or clearing, including those based on interest rates, credit default, equities, foreign exchange, agricultural commodities, energy and metals. Trades are executed through CME Group's electronic trading platforms, open outcry and privately negotiated transactions. Through its clearing houses, CME Group offers clearing, settlement and guarantees for all products cleared through the exchange. CBOT acquired The Board of Trade of Kansas City, Missouri, Inc. (KCBT) and its subsidiaries, the Kansas City Board of Trade Clearing Corporation (KCBTCC) and the Board of Trade Investment Company (BOTIC), on November 30, 2012. KCBT maintained a 51% controlling interest in BOTIC, resulting in a nonredeemable non-controlling interest included in the company's consolidated statements of equity. In April 2013, KCBTCC was integrated into our U.S. clearing operations. As of December 2013, KCBT was no longer regulated as a designated contract market and its operations were transferred to CBOT. The company purchased the non-controlling interest in BOTIC in June 2014.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation. The accompanying consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States and include the accounts of the company and its majority-owned subsidiaries. All intercompany transactions and balances have been eliminated. Use of Estimates. The preparation of consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts and the disclosure of contingent amounts in the consolidated financial statements and accompanying notes. Estimates are based on historical experience, where applicable, and assumptions management believes are reasonable under the circumstances. Due to the inherent uncertainty involved with estimates, actual results may differ. Cash and Cash Equivalents. Cash and cash equivalents consist of cash and highly liquid investments with a maturity of three months or less at the time of purchase. Financial Investments. The company maintains short-term and long-term investments, classified as available-for-sale or trading securities. Available-for-sale investments are carried at their fair value, with unrealized gains and losses, net of deferred income taxes, reported as a component of accumulated other comprehensive income. Trading securities held in connection with non-qualified deferred compensation plans are recorded at fair value, with net realized and unrealized gains and losses and dividend income reported as investment income. Also, the company maintains long-term investments accounted for under the cost method and equity method, depending upon the degree of influence over the investee as held by the company. The company reviews its investments to determine whether a decline in fair value below the cost basis is other-than-temporary. If events and circumstances indicate that a decline in the value of the assets has occurred and is deemed to be other-than-temporary, the carrying value of the investments is reduced to its fair value and a corresponding impairment is charged to earnings. Fair Value of Financial Instruments. The company uses a three-level classification hierarchy of fair value measurements that establishes the quality of inputs used to measure fair value. The fair value of a financial instrument is the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value of financial instruments is determined using various techniques that involve some level of estimation and judgment, the degree of which is dependent on the price transparency and the complexity of the instruments. Derivative Investments. The company uses derivative instruments, designated as cash flow hedges, to limit exposure to changes in interest rates. Derivatives are recorded at fair value in the consolidated balance sheets. The effective portion of the changes in the fair value of cash flow hedges is deferred in accumulated other comprehensive income. Any realized gains and losses from effective hedges are classified as interest expense in the consolidated statements of income, and any ineffective or excluded portion of a hedge is recognized in earnings immediately. Accounts Receivable. Accounts receivable are comprised of trade receivables and unbilled revenue including clearing and transaction fees and market data and information services revenue. All accounts receivable are stated at cost. Exposure to losses on receivables for clearing and transaction fees and other amounts owed by clearing firms is dependent on each clearing firm's financial condition and the memberships that collateralize fees owed to the exchange. The exchange retains the right to liquidate exchange memberships to satisfy a clearing firm's receivable. The allowance for doubtful accounts is calculated based on historical losses and management's assessment of probable future collections. Performance Bonds and Guaranty Fund Contributions. Performance bonds and guaranty fund contributions held for clearing firms may be in the form of cash, securities or other non-cash deposits. Performance bonds and guaranty fund contributions received in the form of cash held by CME and CMECE may be invested in U.S. government securities and certain foreign government securities acquired through and held by a bank or broker-dealer subsidiary of a bank, reverse repurchase agreements secured with highly rated government securities, money market funds or through CME's Interest Earning Facility (IEF) program. Any interest earned on CME investments accrues to CME and is included in investment income in the consolidated statements of income. CME and CMECE may distribute any interest earned on CME and CMECE investments to the clearing firms at their discretion. Because CME and CMECE have control of the cash collateral and the benefits and risks of ownership accrue to CME and CMECE, cash performance bonds and guaranty fund contributions are reflected in the consolidated balance sheets. Performance bonds and guaranty fund contributions assets on the consolidated balance sheets also include U.S. Treasury securities with maturity dates of 90 days or less. U.S. Treasury securities are purchased by CME, at its discretion, using cash collateral. Securities and other non-cash deposits may include U.S. Treasury securities, U.S. government agency securities, Eurobonds, corporate bonds, other foreign government securities and gold bullion. Securities and other non-cash deposits are held in safekeeping by a custodian bank. Interest and gains or losses on securities deposited to satisfy performance bond and guaranty fund requirements accrue to the clearing firm. Because the benefits and risks of ownership accrue to the clearing firm, non-cash performance bonds and guaranty fund contributions are not reflected in the consolidated balance sheets. Cash contributed by CMECE to its guaranty funds is classified as restricted cash and is included in other current assets and other assets in the consolidated balance sheets. Property, Equipment and Leasehold Improvements. Property, equipment and leasehold improvements are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization are calculated using the straight-line method, generally over two to thirty-nine years. Property and equipment are depreciated over their estimated useful lives. Leasehold improvements are amortized over the shorter of the remaining term of the respective lease to which they relate or the remaining useful life of the leasehold improvement. Land is reported at cost. Internal and external costs incurred in developing or obtaining computer software for internal use are capitalized and amortized on a straight-line basis over the estimated useful life of the software, generally two to four years. Operating Leases. All leases in which the company is the tenant are accounted for as operating leases. Landlord allowances are recorded as a reduction to rent expense on a straight-line basis over the term of the lease. Goodwill and Other Intangible Assets. Goodwill represents the excess of the purchase price over the fair value of the net assets acquired in a business combination. The company reviews goodwill and indefinite-lived intangible assets for impairment at least annually and whenever events or circumstances indicate that their carrying values may not be recoverable. The company may test goodwill quantitatively for impairment by comparing the carrying value of a reporting unit to its estimated fair value. Estimating the fair value of a reporting unit involves significant judgments inherent in the analysis including estimating the amount and timing of future cash flows and the selection of appropriate discount rates and long-term growth rate assumptions. Changes in these estimates and assumptions could materially affect the determination of fair value of the reporting unit. If the carrying amount exceeds fair value, impairment is recorded. In certain circumstances, goodwill may be reviewed qualitatively for indications of impairment without utilizing valuation techniques to estimate fair value. The company evaluates the recoverability of indefinite-lived intangible assets by comparing the estimated fair value of the intangible asset to its carrying value. If the indefinite-lived intangible asset carrying value exceeds its fair value, an impairment loss is recognized in an amount equal to that excess. Estimating the fair value of indefinite-lived intangible assets involves the use of valuation techniques that rely on significant estimates and assumptions including forecasted revenue growth rates, forecasted allocations of expense and risk-adjusted discount rates. Changes in these estimates and assumptions could materially affect the determination of fair value for indefinite-lived intangible assets. In certain circumstances, indefinite-lived intangible assets may be reviewed qualitatively for indications of impairment without utilizing valuation techniques to estimate fair value. Intangible assets subject to amortization are also assessed for impairment when indicated by a change in economic or operational circumstances. The impairment assessment of these assets requires management to first compare the book value of the amortizing asset to undiscounted cash flows. If the book value exceeds the undiscounted cash flows, management is then required to estimate the fair value of the assets and record an impairment loss for the excess of the carrying value over the fair value. Business Combinations. The company accounts for business combinations using the acquisition method. The method requires the acquirer to recognize the assets acquired, liabilities assumed, and any non-controlling interest in the acquiree at the acquisition date, measured at their fair values as of that date. The company may use independent valuation services to assist in determining the estimated fair values. Employee Benefit Plans. The company recognizes the funded status of defined benefit postretirement plans in its consolidated balance sheets. Changes in that funded status are recognized in the year of change in other comprehensive income (loss). Plan assets and obligations are measured at year end. The company recognizes future changes in actuarial gains and losses and prior service costs in the year in which the changes occur through other comprehensive income (loss). Foreign Currency Translation . Foreign currency denominated assets and liabilities are re-measured into the functional currency using period-end exchange rates. Gains and losses from foreign currency transactions are included in other expense in the accompanying consolidated statements of income. When the functional currency differs from the reporting currency, revenues and expenses of foreign subsidiaries are translated from their functional currencies into U.S. dollars using weighted-average exchange rates while their assets and liabilities are translated into U.S. dollars using period-end exchange rates. Gains and losses resulting from foreign currency translations are included in accumulated other comprehensive income (loss) within shareholders' equity. Revenue Recognition. Revenue recognition policies for specific sources of revenue are discussed below. Clearing and Transaction Fees. Clearing and transaction fees include per-contract charges for trade execution, clearing, trading on the company's electronic trading platform and other fees. Fees are charged at various rates based on the product traded, the method of trade, the exchange trading privileges of the customer making the trade and the type of contract. Clearing and transaction fees are recognized as revenue when a buy and sell order are matched and the trade is cleared. Therefore, unfilled or canceled buy and sell orders have no impact on revenue. On occasion, the customer's exchange trading privileges may not be properly entered by the clearing firm and incorrect fees are charged for the transactions. When this information is corrected within the time period allowed by the exchange, a fee adjustment is provided to the clearing firm. A reserve is established for estimated fee adjustments to reflect corrections to customer exchange trading privileges. The reserve is based on the historical pattern of adjustments processed as well as specific adjustment requests. The company believes the allowances are adequate to cover estimated adjustments. Market Data and Information Services. Market data and information services represent revenue earned for the dissemination of market information. Revenues are accrued each month based on the number of devices reported by vendors. The exchange conducts periodic examinations of the number of devices reported and assesses additional fees as necessary. On occasion, customers will pay for services in a lump sum payment; however, revenue is recognized as services are provided. Access and Communication Fees. Access fees are the connectivity charges to customers of the company's electronic trading platform that are also used by market data vendors and customers. The fees include co-location fees, access fees for the electronic trading platform, line charges and hardware rental charges and can vary depending on the type of connection provided. An additional installation fee may be charged depending on the type of service requested and a disconnection fee may also be charged if certain conditions are met. Revenue is generally recognized monthly as the service is provided. Communication fees consist of equipment rental and usage charges to customers and firms that utilize various telecommunications hubs located internationally as well as networks and services in the Chicago and New York City facilities. Revenue is billed and recognized on a monthly basis. Other Revenues. Other revenues include processing services revenue, which is revenue generated from various strategic relationships, as well as management fees earned under the IEF programs. For processing services revenue and IEF revenue, revenue is recognized as services are provided. Concentration of Revenue. One firm represented 13% of the company's clearing and transaction fees revenue in 2015 and one firm represented 12% of the company's clearing and transaction fees revenue in 2014 . One firm represented 11% and one firm represented 10% of the company's clearing and transaction fees revenue in 2013 . Should a clearing firm withdraw from the exchange, management believes that the customer portion of that firm's trading activity would likely transfer to another clearing firm. Therefore, management does not believe that the company is exposed to significant risk from the ongoing loss of revenue received from a particular clearing firm. The two largest resellers of market data represented approximately 43% of market data and information services revenue in 2015 , 44% in 2014 , and 52% in 2013 . Should one of these vendors no longer subscribe to the company's market data, management believes that the majority of that firm's customers would likely subscribe to the market data through another reseller. Therefore, management does not believe that the company is exposed to significant risk from a loss of revenue received from any particular market data reseller. Share-Based Payments. The company accounts for share-based payments at fair value, which is based on the grant date price of the equity awards issued. The company recognizes expense relating to stock-based compensation on an accelerated basis. As a result, the expense associated with each vesting date within a stock grant is recognized over the period of time that each portion of that grant vests. The company estimates expected forfeitures of stock grants. Marketing Costs. Marketing costs are incurred for the production and communication of advertising as well as other marketing activities. These costs are expensed when incurred, except for costs related to the production of broadcast advertising, which are expensed when the first broadcast occurs. Income Taxes. Deferred income taxes arise from temporary differences between the tax basis and book basis of assets and liabilities. A valuation allowance is recognized if it is anticipated that some or all of a deferred tax asset may not be realized. The company accounts for uncertainty in income taxes recognized in its consolidated financial statements by using a more-likely-than-not recognition threshold based on the technical merits of the tax position taken or expected to be taken. The company classifies interest and penalties related to uncertain tax positions in income tax expense. Segment Reporting. The company reports the results of its operations as one operating segment primarily comprised of CME, CBOT, NYMEX and COMEX. The remaining operations do not meet the thresholds for reporting separate segment information.

Marketable Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2015
Marketable Securities [Abstract]
Marketable Securities	MARKETABLE SECURITIES Available-for-Sale Securities. Certain marketable securities have been classified as available-for-sale. The amortized cost and fair value of these securities at December 31 were as follows: 2015 2014 (in millions) Amortized Cost Fair Value Amortized Cost Fair Value U.S. Treasury securities $ 16.1 $ 16.2 $ 19.1 $ 19.1 Asset-backed security 0.7 0.3 0.7 0.4 Equity securities 0.1 0.1 0.1 0.1 Total $ 16.9 $ 16.6 $ 19.9 $ 19.6 Net unrealized gains (losses) on marketable securities classified as available-for-sale are reported as a component of other comprehensive income (loss) and included in the accompanying consolidated statements of comprehensive income and consolidated statements of equity. The fair value and gross unrealized losses of the asset-backed security were $0.3 million and $0.4 million , respectively, at December 31, 2015 . The asset-backed security was in an unrealized loss position for more than 12 months at December 31, 2015 and was deemed not to be other-than-temporarily impaired. The company does not intend to sell and is not required to sell this asset-backed security prior to maturity. The amortized cost and fair value of the U.S. Treasury securities and asset-backed security at December 31, 2015 , by contractual maturity, were as follows: (in millions) Amortized Cost Fair Value Maturity of one year or less $ 16.1 $ 16.2 Maturity between one and five years — — Maturity between five and ten years — — Maturity greater than ten years 0.7 0.3 Total $ 16.8 $ 16.5 Trading Securities. The company maintains additional investments in a diverse portfolio of mutual funds related to its non-qualified deferred compensation plans (note 11). The fair value of these securities was $55.9 million and $55.1 million at December 31, 2015 and 2014 , respectively.

Performance Bonds and Guaranty

Performance Bonds and Guaranty Fund Contributions	12 Months Ended
	Dec. 31, 2015
Performance Bonds and Guaranty Fund Contributions [Abstract]
Performance Bonds and Guaranty Fund Contributions	PERFORMANCE BONDS AND GUARANTY FUND CONTRIBUTIONS The company operates two clearing houses: CME Clearing (a division of CME) and CMECE. The clearing houses clear and guarantee the settlement of contracts traded in their respective markets. In their guarantor roles, the clearing houses have precisely equal and offsetting claims to and from clearing firms on opposite sides of each contract, standing as an intermediary on every contract cleared. Clearing firm positions in the United States are held according to Commodity and Futures Trading Commission (CFTC) regulatory account segregation standards. To the extent that funds are not otherwise available to satisfy an obligation under the applicable contract, the clearing houses bear counterparty credit risk in the event that future market movements create conditions that could lead to clearing firms failing to meet their obligations to the clearing houses. The clearing houses reduce the exposure through risk management programs that include initial and ongoing financial standards for designation as a clearing firm, performance bond requirements, daily mark-to-market, mandatory guaranty fund contributions and intra-day monitoring. Each CME clearing firm is required to deposit and maintain balances in the form of cash, U.S. government securities, certain foreign government securities, bank letters of credit or other approved investments to satisfy performance bond and guaranty fund requirements. Clearing firms that clear through CMECE are required to deposit and maintain collateral in the form of cash, certain U.S. and foreign government securities or other approved investments to satisfy performance bond and guaranty fund requirements. All non-cash deposits are marked-to-market and haircut on a daily basis. Securities deposited by the clearing firms are not reflected in the consolidated financial statements and the clearing houses do not earn any interest on these deposits. These balances may fluctuate significantly over time due to investment choices available to clearing firms and changes in the amount of contributions required. In addition, the rules and regulations of CBOT require that collateral be provided for delivery of physical commodities, maintenance of capital requirements and deposits on pending arbitration matters. To satisfy these requirements, clearing firms that have accounts that trade certain CBOT products have deposited cash, U.S. Treasury securities or letters of credit. The clearing houses mark-to-market open positions at least once a day (twice a day for futures and options contracts), and require payment from clearing firms whose positions have lost value and make payments to clearing firms whose positions have gained value. The clearing houses have the capability to mark-to-market more frequently as market conditions warrant. Under the extremely unlikely scenario of simultaneous default by every clearing firm who has open positions with unrealized losses, the maximum exposure related to positions other than credit default and interest rate swap contracts would be one half day of changes in fair value of all open positions, before considering the clearing houses' ability to access defaulting clearing firms' collateral deposits. For CME's cleared credit default swap and interest rate swap contracts, the maximum exposure related to CME's guarantee would be one full day of changes in fair value of all open positions, before considering CME's ability to access defaulting clearing firms' collateral. During 2015 , the clearing houses transferred an average of approximately $3.9 billion a day through their clearing systems for settlement from clearing firms whose positions had lost value to clearing firms whose positions had gained value. The clearing houses reduce the guarantee exposure through initial and maintenance performance bond requirements and mandatory guaranty fund contributions. The company believes that the guarantee liability is immaterial and therefore has not recorded any liability at December 31, 2015 . At December 31, 2015 , performance bond and guaranty fund contribution assets on the consolidated balance sheets include cash and U.S. Treasury securities with maturity dates of 90 days or less. U.S. Treasury securities are purchased by CME, at its discretion, using cash collateral. The benefits, including interest earned, and risks of ownership accrue to CME. Interest earned is included in investment income on the consolidated statements of income. At December 31, 2015 , the amortized cost and fair value of the U.S. Treasury securities were both $11.0 billion . At December 31, 2014 , the amortized cost and fair value of the U.S. Treasury securities were both $16.7 billion . The U.S. Treasury securities held at December 31, 2015 will mature during the first quarter of 2016. CME Clearing Clearing firms, at their option, may instruct CME to deposit the cash held by CME into one of the IEF programs. The total principal in the IEF programs was $11.3 billion at December 31, 2015 and $16.4 billion at December 31, 2014 . The consolidated statements of income reflect management fees earned under the IEF programs of $11.3 million , $14.9 million and $13.9 million during 2015 , 2014 and 2013 , respectively. These fees are included in other revenues. CME and The Options Clearing Corporation (OCC) have a perpetual cross-margin arrangement, whereby a clearing firm may maintain a cross-margin account in which a CME clearing firm's positions in certain equity index futures and options are combined with certain positions cleared by OCC for purposes of calculating performance bond requirements. The performance bond deposits are held jointly by CME and OCC. Cross-margin cash, securities and letters of credit jointly held with OCC under the cross-margin agreement are reflected at 50% of the total, or CME's proportionate share per that agreement. If a participating firm defaults, the gain or loss on the liquidation of the firm's open position and the proceeds from the liquidation of the cross-margin account would be allocated 50% each to CME and OCC. The company believes that the guarantee liability is immaterial and therefore has not recorded any liability at December 31, 2015 . In addition, CME has perpetual cross-margin agreements with Fixed Income Clearing Corporation (FICC) whereby the clearing firms' offsetting positions with CME and FICC are subject to reduced performance bond requirements. Clearing firms maintain separate performance bond deposits with each clearing house, but depending on the net offsetting positions between CME and FICC, each clearing house may reduce that firm's performance bond requirements. In the event of a firm default, the total liquidation net gain or loss on the firm's offsetting open positions and the proceeds from the liquidation of the performance bond collateral held by each clearing house's supporting offsetting positions would be divided evenly between CME and FICC. Additionally, if, after liquidation of all the positions and collateral of the defaulting firm at each respective clearing organization, and taking into account any cross-margining loss sharing payments, any of the participating clearing organizations has a remaining liquidating surplus, and any other participating clearing organization has a remaining liquidating deficit, any additional surplus from the liquidation would be shared with the other clearing house to the extent that it has a remaining liquidating deficit. Any remaining surplus funds would be passed to the bankruptcy trustee. The company believes that the guarantee liability is immaterial and therefore has not recorded any liability at December 31, 2015 . Each CME clearing firm for futures and options is required to deposit and maintain specified guaranty fund contributions in the form of cash or approved securities. In the event that performance bonds, guaranty fund contributions and other assets required to support clearing membership of a defaulting CME clearing firm are inadequate to fulfill that clearing firm's outstanding financial obligation, the base guaranty fund for contracts other than credit default and interest rate swaps is available to cover potential losses after first utilizing $100.0 million of corporate contributions designated by CME to be used in the event of a default of a clearing firm for the base guaranty fund. CME maintains separate guaranty funds to support the clearing firms that clear interest rate swap products and credit default swap products. The funds for interest rate and credit default swaps are independent of the base guaranty fund and are isolated to clearing firms for products in the respective asset class. Each clearing firm for cleared interest rate swaps and cleared credit default swaps is required to deposit and maintain specified guaranty fund contributions in the form of cash or approved securities. In the event that performance bonds, guaranty fund contributions and other assets required to support clearing membership of a defaulting clearing firm for cleared interest rate swap contracts are inadequate to fulfill that clearing firm's outstanding financial obligation, the interest rate swaps contracts guaranty fund is available to cover potential losses after first utilizing $150.0 million of corporate contributions designated by CME to be used in the event of a default of a cleared interest rate swap clearing firm. In the event that performance bonds, guaranty fund contributions and other assets required to support clearing membership of a defaulting clearing firm for cleared credit default swap contracts are inadequate to fulfill that clearing firm's outstanding financial obligation, the credit default swaps contracts guaranty fund is available to cover potential losses after first utilizing corporate contributions designated by CME to be used in the event of default of a cleared credit default swap clearing firm, which is equal to the greater of $50.0 million and 5% of the credit default swap guaranty fund, up to a maximum of $100.0 million . CME maintains a 364 -day multi-currency line of credit with a consortium of domestic and international banks to be used in certain situations by CME Clearing. CME may use the proceeds to provide temporary liquidity in the unlikely event of a clearing firm default, in the event of a liquidity constraint or default by a depositary (custodian of the collateral), or in the event of a temporary disruption with the domestic payments system that would delay payment of settlement variation between CME and its clearing firms. Clearing firm guaranty fund contributions received in the form of cash or U.S. Treasury securities as well as the performance bond assets of a defaulting firm can be used to collateralize the facility. The line of credit provides for borrowings of up to $7.0 billion . At December 31, 2015 , guaranty fund contributions available for CME clearing firms were $6.4 billion . CME has the option to request an increase in the line from $7.0 billion to $10.0 billion , subject to the approval of participating banks. In addition to the 364 -day fully secured, committed multi-currency line of credit, the company also has the option to use the $2.3 billion multi-currency revolving senior credit facility to provide liquidity for the clearing house in the unlikely event of default. CMECE CMECE maintains a guaranty fund for CMECE commodity and foreign exchange clearing firms. In the unlikely event of default by a CMECE clearing firm, CMECE would first apply assets of the defaulting clearing firm to satisfy its payment obligations. These assets include the defaulting firm's performance bonds and guaranty fund contributions. Thereafter, if the default remains unsatisfied after first applying assets of the defaulting clearing firm to satisfy its payment obligation, CMECE would use guaranty fund contributions of $52.0 million of CMECE funds. At December 31, 2015, clearing firms contribution to the commodity and foreign exchange guaranty fund was $10.6 million . Once clearing firms fully contribute to the guaranty fund, CMECE will still use at least $20.0 million of CMECE funds in addition to the commodity or foreign exchange clearing firms' guaranty fund contributions in the event of a default. CMECE also maintains a guaranty fund for CMECE interest rate swap clearing firms. In the unlikely event of default by a CMECE clearing firm, CMECE would first apply assets of the defaulting clearing firm to satisfy its payment obligations. These assets include the defaulting firm's performance bonds and guaranty fund contributions. If the default remains unsatisfied, CMECE would apply guaranty fund contributions of $48.2 million for interest rate swap clearing firms that will be contributed by CMECE. Interest rate swap clearing firm contributions to the interest rate swap guaranty fund totaled $94.9 million at December 31, 2015 . CME is required under the Commodity Exchange Act in the United States to segregate cash and securities deposited by clearing firms on behalf of its customers. In addition, CME requires segregation of all funds deposited by its clearing firms from operating funds. CMECE holds cash and securities deposited by clearing firms in segregated accounts, and maintains distinct accounts for its own operating funds. Cash and non-cash deposits held as performance bonds and guaranty fund contributions at fair value at December 31 for CME and CMECE were as follows: 2015 2014 (in millions) Cash Non-Cash Deposits and IEF Funds Cash Non-Cash Deposits and IEF Funds Performance bonds 1 $ 33,592.8 $ 91,954.4 $ 38,729.0 $ 93,972.7 Guaranty fund contributions 1,919.2 5,290.0 1,719.9 5,699.0 Cross-margin arrangements 37.8 163.7 102.2 91.2 Performance collateral for delivery 3.2 — 15.7 2.1 Total $ 35,553.0 $ 97,408.1 $ 40,566.8 $ 99,765.0 (1) Cash performance bonds include cash collateral reinvested in U.S. Treasury securities. Performance bonds and guaranty fund contributions include collateral for clearing firms for both clearing houses. Cross-margin arrangements include collateral for the cross-margin accounts with OCC and FICC. The performance bond collateral for delivery includes deposits to meet CBOT delivery requirements. Cash performance bonds may include intraday settlement, if any, that is owed to the clearing firms and paid the following business day. The balance of intraday settlements was $210.2 million and $224.2 million at December 31, 2015 and 2014 , respectively. Intraday settlements may be invested on an overnight basis and are offset by an equal liability owed to clearing firms. In addition to cash, securities and other non-cash deposits, irrevocable letters of credit may be used as performance bond deposits for clearing firms. At December 31, these letters of credit, which are not included in the accompanying consolidated balance sheets, were as follows: (in millions) 2015 2014 Performance bonds $ 2,617.6 $ 2,441.9 Guaranty fund contributions 25.0 25.0 Cross-margin arrangements — 5.5 Performance collateral for delivery 1,208.0 950.4 Total Letters of Credit $ 3,850.6 $ 3,422.8 All cash, securities and letters of credit posted as performance bonds are only available to meet the financial obligations of that clearing firm to the clearing houses.

Property

Property	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment, Net [Abstract]
Property	PROPERTY A summary of the property accounts at December 31 is presented below: (in millions) 2015 2014 Estimated Useful Life Land and land improvements $ 17.7 $ 17.7 10 - 20 years (1) Building and building improvements 280.8 273.5 3 - 39 years Leasehold improvements 248.5 219.1 3 - 24 years Furniture, fixtures and equipment 333.3 360.1 2 - 7 years Software and software development costs 400.0 379.5 2 - 4 years Total property 1,280.3 1,249.9 Less accumulated depreciation and amortization (788.6 ) (741.0 ) Property, net $ 491.7 $ 508.9 (1) Estimated useful life applies only to land improvements.

Intangible Assets and Goodwill

Intangible Assets and Goodwill	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets and Goodwill	INTANGIBLE ASSETS AND GOODWILL Intangible assets consisted of the following at December 31: 2015 2014 (in millions) Assigned Value Accumulated Amortization Net Book Value Assigned Value Accumulated Amortization Net Book Value Amortizable Intangible Assets: Clearing firm, market data and other customer relationships $ 2,838.8 $ (754.5 ) $ 2,084.3 $ 2,838.8 $ (658.8 ) $ 2,180.0 Technology-related intellectual property 29.4 (27.2 ) 2.2 29.4 (23.5 ) 5.9 Other 2.4 (1.0 ) 1.4 2.4 (0.9 ) 1.5 Total amortizable intangible assets $ 2,870.6 $ (782.7 ) 2,087.9 $ 2,870.6 $ (683.2 ) 2,187.4 Indefinite-Lived Intangible Assets: Trade names 450.0 450.0 Total intangible assets—other, net $ 2,537.9 $ 2,637.4 Trading products (1) $ 17,175.3 $ 17,175.3 _______________ (1) Trading products represent futures and options products acquired in our business combinations with CBOT Holdings, Inc., NYMEX Holdings, Inc. and KCBT. Clearing and transaction fees are generated through the trading of these products. These trading products, most of which have traded for decades, require authorization from the CFTC. Product authorizations from the CFTC have no term limits. The originally assigned useful lives for the amortizable intangible assets as of December 31, 2015 are as follows: Clearing firm, market data and other customer relationships 5 - 30 years Technology-related intellectual property 4 - 5 years Other 3 - 24.5 years Total amortization expense for intangible assets was $99.4 million , $100.6 million and $103.0 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. As of December 31, 2015 , the future estimated amortization expense related to amortizable intangible assets is expected to be as follows: (in millions) 2016 $ 96.1 2017 95.5 2018 94.7 2019 94.7 2020 94.7 Thereafter 1,612.2 Goodwill activity consisted of the following for the years ended December 31, 2015 and 2014 : (in millions) Balance at December 31, 2014 Business Combinations Divestitures Other Activity Balance at December 31, 2015 CBOT Holdings $ 5,035.7 $ — $ 30.7 $ — $ 5,066.4 NYMEX Holdings 2,462.2 — — — 2,462.2 Other 71.1 — (30.7 ) — 40.4 Total Goodwill $ 7,569.0 $ — $ — $ — $ 7,569.0 (in millions) Balance at December 31, 2013 Business Combinations Divestitures Other Activity Balance at December 31, 2014 CBOT Holdings $ 5,035.7 $ — $ — $ — $ 5,035.7 NYMEX Holdings 2,462.2 — — — 2,462.2 Other 71.1 — — — 71.1 Total Goodwill $ 7,569.0 $ — $ — $ — $ 7,569.0

Long-term Investments

Long-term Investments	12 Months Ended
	Dec. 31, 2015
Long-term Investments [Abstract]
Long-term Investments	LONG-TERM INVESTMENTS The company maintains various long-term investments as described below. The investments are recorded in other assets in the consolidated balance sheets. BM&FBOVESPA S.A. The company owns an approximate 4% interest in BM&FBOVESPA S. A. (BM&FBOVESPA). BM&FBOVESPA is a stock and derivatives exchange in Brazil. The company accounts for its investment in BM&FBOVESPA as an available-for-sale security. During 2015, the company sold approximately 41.0 million shares of BM&FBOVESPA and recognized a net loss of $8.5 million within investment income on the consolidated statements of income based on the average cost method. The fair value of the investment was $199.1 million and $410.8 million at December 31, 2015 and 2014 , respectively. The cost basis of the investment was $258.4 million and $405.7 million at December 31, 2015 and 2014 , respectively. Substantially all of the difference between the cost basis and fair value of the investment as of December 31, 2015 represents previous changes in foreign currency exchange rates that are suspended in accumulated other comprehensive income and released into current operations as the investment is sold. The company and BM&FBOVESPA have entered into several agreements including co-location, licensing, order routing and technology development arrangements. Bolsa Mexicana de Valores, S.A.B de C.V. The company owns an approximate 2% interest in Bolsa Mexicana de Valores, S.A.B. de C.V. (Bolsa Mexicana), a financial exchange operator in Mexico. The company accounts for its investment in Bolsa Mexicana stock as an available-for-sale security. The fair value of the investment in Bolsa Mexicana at December 31, 2015 and 2014 was $15.5 million and $21.2 million , respectively. The cost basis of the investment was $17.3 million at December 31, 2015 and 2014 . The company and Bolsa Mexicana maintain a strategic partnership that includes an order routing agreement for derivative products. Bursa Malaysia Derivatives Berhad. The company owns a 25% interest in Bursa Malaysia Derivatives Berhad (Bursa Malaysia), and accounts for its investment in Bursa Malaysia using the equity method of accounting. The company's investment in Bursa Malaysia was $28.0 million at December 31, 2015 . The company and Bursa Malaysia have entered into several agreements including agreements to provide licensing, order routing and trade matching services. DME Holdings Limited. The company owns an approximate 50% interest in DME Holdings Limited (DME Holdings), and accounts for its investment in DME Holdings using the equity method of accounting. The company's investment in DME Holdings was $17.5 million at December 31, 2015 . The company and DME Holdings maintain an agreement for Dubai Mercantile Exchange (DME) futures contracts to be exclusively traded on the CME Globex platform. S&P/DJI Indices LLC. The company owns a 27% interest in S&P/Dow Jones Indices LLC (S&P/DJI) and accounts for its investment in S&P/DJI using the equity method of accounting. The company's investment in S&P/DJI was $938.7 million at December 31, 2015. The company has long-term exclusive licensing agreements with S&P/DJI to list products based on the Standard & Poor's Indices and Dow Jones Indices.

Debt

Debt	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Debt	DEBT In April 2015, the company repaid the $612.5 million fixed rate notes due 2018 and paid a call premium of $60.5 million . As a result of the transaction, the company recognized debt prepayment costs of $61.8 million in the second quarter of 2015, which includes the call premium. Long-term debt consisted of the following at December 31: (in millions) 2015 2014 $612.5 million fixed rate notes due March 2018, stated rate of 4.40% (1) $ — $ 611.0 $750.0 million fixed rate notes due September 2022, stated rate of 3.00% (2) 748.4 748.2 $750.0 million fixed rate notes due March 2025, stated rate of 3.00% (3) 744.2 — $750.0 million fixed rate notes due September 2043, stated rate of 5.30% (4) 748.8 748.7 Total long-term debt $ 2,241.4 $ 2,107.9 _______________ (1) In February 2010, the company entered into a forward-starting interest rate swap agreement that modified the interest obligation associated with these notes so that the interest payable on the notes effectively became fixed at a rate of 4.46% . (2) In August 2012, the company entered into a forward-starting interest rate swap agreement that modified the interest obligation associated with these notes so that the interest payable on the notes effectively became fixed at a rate of 3.32% . (3) In December 2014, the company entered into a forward-starting interest rate swap agreement that modified the interest obligation associated with these notes so that the interest payable on the notes effectively became fixed at a rate of 3.11% . (4) In August 2012, CME Group entered into a forward-starting interest rate swap agreement that modified the interest obligation associated with these notes so that the interest payable on the notes effectively became fixed at a rate of 4.73% . Long-term debt maturities, at par value, were as follows as of December 31, 2015 : (in millions) Par Value 2016 $ — 2017 — 2018 — 2019 — 2020 — Thereafter 2,250.0

Derivative Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2015
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Derivative Instruments	DERIVATIVE INVESTMENTS The company mitigates certain financial exposures to interest rate risk through the use of derivative financial instruments as part of its risk management program. All derivatives have been designated as cash flow hedges. In December 2014, the company entered into a forward-starting interest rate swap contract, with a notional value of $500.0 million , to hedge the risk of changes in underlying benchmark interest rates associated with the issuance of fixed rate debt in 2015. The hedge was considered highly effective. The effective portion is included in other comprehensive income and is being amortized over the term of the debt. The fair value and location of outstanding derivative instruments in the consolidated balance sheet were as follows at December 31: (in millions) Balance Sheet Location 2015 2014 Interest rate contract Other current liabilities $ — $ 2.3 The pre-tax effect of derivative instruments on the consolidated statements of income as well as accumulated other comprehensive income (OCI) within the consolidated statements of comprehensive income and consolidated statements of shareholders' equity for the years ended December 31, 2015 and 2014 were as follows: Gains (Losses) Recognized in OCI (Effective Portion) (Gains) Losses Reclassified from Accumulated OCI (Effective Portion) Gains (Losses) Recognized in Income (Ineffective Portion) (in millions) 2015 2014 Location 2015 2014 Location 2015 2014 Interest rate contracts $ (4.7 ) $ (2.3 ) Interest and other borrowing costs $ (1.2 ) $ (1.5 ) Gains (losses) on derivative investments $ (1.8 ) $ — At December 31, 2015 , the company expects to reclassify $1.2 million of net gains on derivative instruments from accumulated other comprehensive income to net income as a net reduction to interest expense during the next twelve months.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The company is subject to regulation under a wide variety of U.S., federal, state and foreign tax laws and regulations. Income before income taxes and the income tax provision consisted of the following for the years ended December 31: (in millions) 2015 2014 2013 Income before income taxes: Domestic $ 1,927.3 $ 1,783.7 $ 1,599.2 Foreign 29.5 (12.3 ) 1.8 Total $ 1,956.8 $ 1,771.4 $ 1,601.0 Income tax provision: Current: Federal $ 554.5 $ 526.4 $ 491.9 State 81.0 36.5 128.8 Foreign 11.0 2.7 8.2 Total 646.5 565.6 628.9 Deferred: Federal 75.6 47.1 (157.6 ) State (12.0 ) 32.4 153.4 Foreign (0.3 ) (0.6 ) (1.8 ) Total 63.3 78.9 (6.0 ) Total Income Tax Provision $ 709.8 $ 644.5 $ 622.9 Reconciliation of the statutory U.S. federal income tax rate to the effective tax rate is as follows: 2015 2014 2013 Statutory U.S. federal tax rate 35.0 % 35.0 % 35.0 % State taxes, net of federal benefit 3.0 1.6 4.8 Domestic production activities deduction (1.3 ) (1.4 ) (7.7 ) Increase (decrease) in domestic valuation allowance 0.1 0.1 0.6 Impact of revised state and local apportionment estimates (0.7 ) 1.1 6.6 Other, net 0.2 — (0.4 ) Effective Tax Rate 36.3 % 36.4 % 38.9 % In 2015, the effective rate was higher than the statutory tax rate primarily due to the impact of state and local income taxes. The effective rate was primarily reduced by the Section 199 Domestic Productions Activities Deduction (Section 199 deduction) and the impact of state and local apportionment factors in deferred tax expense. The Section 199 deduction is related to certain activities performed by the company's electronic platform. In 2014, the effective tax rate was higher than the statutory tax rate largely due to state income taxes and the impact of revised state and local apportionment factors on the company's deferred tax expense. However, the state income tax expense was reduced for benefits achieved in various settlements of state and local income tax audits. The effective tax rate was primarily reduced by the Section 199 deduction. In 2013, the effective tax rate was higher than the statutory tax rate due to changes in estimate of state and local income tax apportionment factors. The changes in estimate of state and local income tax apportionment factors significantly impacted the company’s deferred tax expense and expense related to uncertain tax positions. The increase in effective tax rate was partially offset by benefits accrued for the Section 199 deduction. The benefits accrued include the 2013 estimated benefit as well as benefits accrued for prior periods in which tax returns have been filed claiming the deduction or are expected to be filed claiming the deduction. At December 31, deferred income tax assets (liabilities) consisted of the following: (in millions) 2015 2014 Net Current Deferred Income Tax Assets: Unrealized loss on securities $ 1.1 $ 3.0 Stock-based compensation 19.1 19.2 Accrued expenses and other 7.7 2.2 Net Current Deferred Income Tax Assets $ 27.9 $ 24.4 Net Non-Current Deferred Income Tax Assets: Domestic unrealized loss on investment in BM&FBOVESPA $ 85.6 $ 101.7 Foreign losses 15.6 19.7 Domestic losses 14.1 7.3 Stock-based compensation 24.1 30.7 Deferred compensation and other benefit plans 31.8 38.1 Property 27.3 44.3 Unrealized losses on securities 14.9 16.5 Subtotal 213.4 258.3 Valuation allowance (122.3 ) (99.2 ) Total non-current deferred income tax assets 91.1 159.1 Non-Current Deferred Income Tax Liabilities: Purchased intangible assets (7,434.1 ) (7,448.2 ) Other (15.3 ) (13.6 ) Total non-current deferred income tax liabilities (7,449.4 ) (7,461.8 ) Net Non-Current Deferred Income Tax Liabilities $ (7,358.3 ) $ (7,302.7 ) A valuation allowance is recorded when it is more-likely-than-not that some portion or all of the deferred income tax assets may not be realized. The ultimate realization of the deferred income tax assets depends on the ability to generate sufficient taxable income of the appropriate character in the future and in the appropriate taxing jurisdictions. At December 31, 2015 and 2014, the company had domestic and foreign income tax loss carry forwards of $124.5 million and $118.9 million , respectively. These amounts primarily related to losses from the acquisition of Swapstream Limited and its affiliates, the acquisition of Pivot, Inc., losses incurred in the operation of various foreign entities and capital losses from the sales of securities. At December 31, 2015 and 2014, the company also had net built-in, unrealized capital losses of $270.9 million and $317.7 million , respectively. At December 31, 2015 and 2014, the company determined that it was not more-likely-than-not that deferred income tax assets related to the acquisition of Swapstream Limited and its affiliates, other deferred income tax assets created from the start-up of various foreign operations, certain capital losses and certain built-in losses will be fully realized. As a result, valuation allowances of $122.3 million and $99.2 million were recorded at December 31, 2015 and 2014, respectively. The following is a summary of the company’s unrecognized tax benefits: (in millions) 2015 2014 2013 Gross unrecognized tax benefits $ 206.9 $ 187.6 $ 231.6 Unrecognized tax benefits, net of tax impacts in other jurisdictions 179.6 160.8 183.3 Unrecognized interest and penalties related to uncertain tax positions 19.5 11.0 42.5 Interest and penalties recognized in the consolidated statements of income 8.6 (12.5 ) 22.4 The company does not believe it is reasonably possible that within the next twelve months, unrecognized tax benefits will change by a significant amount. A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows: (in millions) 2015 2014 2013 Balance at January 1 $ 187.6 $ 231.6 $ 37.7 Additions based on tax positions related to the current year 20.4 30.5 26.1 Additions for tax positions of prior years 2.7 24.9 168.4 Reductions for tax positions of prior years (3.8 ) (51.8 ) (0.4 ) Reductions resulting from the lapse of statutes of limitations — — (0.2 ) Settlements with taxing authorities — (47.6 ) — Balance at December 31 $ 206.9 $ 187.6 $ 231.6 The company is subject to U.S. federal income tax as well as income taxes in Illinois and multiple other state, local and foreign jurisdictions. As of December 31, 2015 , substantially all federal and state income tax matters had been concluded through 2007 and 2006, respectively.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2015
General Discussion of Pension and Other Postretirement Benefits [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS Pension Plans. CME maintains a non-contributory defined benefit cash balance pension plan for eligible employees. CME's plan provides for a pay-based credit added to the cash balance account based on age and earnings and includes salary and cash bonuses in the definition of earnings. Employees who have completed a continuous 12-month period of employment and have reached the age of 21 are eligible to participate. Participant cash balance accounts receive an interest credit equal to the greater of the one-year constant maturity yield for U.S. Treasury notes or 4.0% . Participants become vested in their accounts after three years of service. The measurement date used for the plan is December 31. The following is a summary of the change in projected benefit obligation: (in millions) 2015 2014 Balance at January 1 $ 223.7 $ 175.7 Service cost 18.4 17.1 Interest cost 9.8 9.6 Actuarial (gain) loss (11.6 ) 30.1 Benefits paid (23.0 ) (8.8 ) Balance at December 31 $ 217.3 $ 223.7 The aggregate accumulated benefit obligation was $190.8 million and $195.6 million at December 31, 2015 and 2014 , respectively. The following is a summary of the change in fair value of plan assets: (in millions) 2015 2014 2013 Balance at January 1 $ 225.1 $ 193.6 $ 183.9 Actual return on plan assets (7.2 ) 14.3 18.1 Employer contributions 22.6 26.0 — Benefits paid (23.0 ) (8.8 ) (8.4 ) Balance at December 31 $ 217.5 $ 225.1 $ 193.6 The plan assets are classified into a fair value hierarchy in their entirety based on the lowest level of input that is significant to each asset or liability’s fair value measurement. Valuation techniques for level 2 assets use significant observable inputs such as quoted prices for similar assets, quoted market prices in inactive markets and other inputs that are observable or can be supported by observable market data. The fair value of each major category of plan assets as of December 31 is indicated below. (in millions) 2015 2014 Level 2: Money market funds $ 26.5 $ 27.2 Mutual funds: Fixed income 61.6 67.2 Foreign equity 60.0 57.6 U.S. equity 59.9 63.4 Commodity 9.5 9.7 Total $ 217.5 $ 225.1 At December 31, 2015 and 2014 , the fair value of pension plan assets exceeded the projected benefit obligation by $0.2 million and $1.4 million , respectively. This excess was recorded as a non-current pension asset in other assets in the consolidated balance sheet. CME's funding goal is to have its pension plan 100% funded at each year-end on a projected benefit obligation basis, while also satisfying any minimum required contribution and obtaining the maximum tax deduction. Year-end 2015 assumptions have been used to project the assets and liabilities from December 31, 2015 to December 31, 2016 . The result of this projection is that estimated liabilities would exceed the fair value of the plan assets at December 31, 2016 by approximately $11.7 million . Accordingly, it is estimated that a $11.7 million contribution in 2016 will allow the company to meet its funding goal. The components of net pension expense and the assumptions used to determine the end-of-year projected benefit obligation and net pension expense in aggregate are indicated below: (in millions) 2015 2014 2013 Components of Net Pension Expense: Service cost $ 18.4 $ 17.1 $ 18.0 Interest cost 9.8 9.6 7.9 Expected return on plan assets (16.3 ) (14.0 ) (13.3 ) Recognized net actuarial loss 2.7 0.6 3.1 Net Pension Expense $ 14.6 $ 13.3 $ 15.7 Assumptions Used to Determine End-of-Year Benefit Obligation: Discount rate 4.60 % 4.20 % 5.10 % Rate of compensation increase 5.00 5.00 5.00 Cash balance interest crediting rate 4.00 4.00 4.00 Assumptions Used to Determine Net Pension Expense: Discount rate 4.20 % 5.10 % 4.10 % Rate of compensation increase 5.00 5.00 5.00 Expected return on plan assets 7.50 7.50 7.50 Interest crediting rate 4.00 4.00 4.00 The discount rate for the plan was determined based on the market value of a theoretical settlement bond portfolio. This portfolio consisted of U.S. dollar denominated Aa-rated corporate bonds across the full maturity spectrum. A single equivalent discount rate was determined to align the present value of the required cash flow with that settlement value. The resulting discount rate was reflective of both the current interest rate environment and the plan's distinct liability characteristics. The basis for determining the expected rate of return on plan assets for the plan is comprised of three components: historical returns, industry peers and forecasted return. The plan's total return is expected to equal the composite performance of the security markets over the long term. The security markets are represented by the returns on various domestic and international stock, bond and commodity indexes. These returns are weighted according to the allocation of plan assets to each market and measured individually. The overall objective of the plan is to achieve required long-term rates of return in order to meet future benefit payments. The component of the investment policy for the plan that has the most significant impact on returns is the asset mix. The asset mix has a minimum and maximum range depending on asset class. The plan assets are diversified to minimize the risk of large losses by any one or more individual assets. Such diversification is accomplished, in part, through the selection of asset mix and investment management. The asset allocation for the plan, by asset category, at December 31 was as follows: 2015 2014 Fixed income 28.3 % 29.8 % Foreign equity 27.6 25.6 U.S. equity 27.5 28.2 Money market funds 12.2 12.1 Commodity 4.4 4.3 The range of target allocation percentages for 2016 is as follows: Minimum Maximum Fixed income 33.0 % 45.0 % U.S. equity 23.5 35.0 Foreign equity 23.5 35.0 Commodity 2.0 8.0 At times, the company may determine that it is necessary to place some assets in cash equivalent investments in order to pay expected plan liabilities. Given this, the actual asset allocation for the plan may not fall within the target allocation ranges from time to time. According to the plan's investment policy, the plan is not allowed to invest in securities that compromise independence, short sales of securities directly owned by the plan, securities purchased on margin or other uses of borrowed funds, derivatives not used for hedging purposes, restricted stock or illiquid securities or any other transaction prohibited by employment laws. If the plan directly invests in short-term and long-term debt obligations, the investments are limited to obligations rated at the highest rating category by Standard & Poor's (S&P) or Moody's. The pre-tax balance and activity of the prior service costs and actuarial losses for the pension plan, which are included in other comprehensive income (loss), for 2015 are as follows: (in millions) Prior Service Costs Actuarial Loss Balance at January 1 $ 0.1 $ 51.6 Unrecognized net loss — 11.9 Recognized as a component of net pension expense — (2.7 ) Balance at December 31 $ 0.1 $ 60.8 The company expects to amortize $3.5 million of actuarial loss and prior service costs from accumulated other comprehensive income (loss) into net periodic benefit costs in 2016 . At December 31, 2015 , anticipated benefit payments from the plan in future years are as follows: (in millions) 2016 $ 14.1 2017 14.7 2018 15.6 2019 17.1 2020 18.0 2021-2025 113.8 Savings Plans. CME maintains a defined contribution savings plan pursuant to Section 401(k) of the Internal Revenue Code, whereby all U.S. employees are participants and have the option to contribute to this plan. CME matches employee contributions up to 3% of the employee's base salary and may make additional discretionary contributions. In addition to the plan for U.S. employees, the company maintains defined contribution savings plans for employees in international locations. Aggregate expense for all of the defined contribution savings plans amounted to $11.7 million , $11.2 million and $9.9 million in 2015 , 2014 and 2013 , respectively. CME Non-Qualified Plans. CME maintains non-qualified plans, under which participants may make assumed investment choices with respect to amounts contributed on their behalf. Although not required to do so, CME invests such contributions in assets that mirror the assumed investment choices. The balances in these plans are subject to the claims of general creditors of the exchange and totaled $55.9 million and $55.1 million at December 31, 2015 and 2014 respectively. Although the value of the plans is recorded as an asset in marketable securities in the consolidated balance sheets, there is an equal and offsetting liability. The investment results of these plans have no impact on net income as the investment results are recorded in equal amounts to both investment income and compensation and benefits expense. Supplemental Savings Plan. CME maintains a supplemental plan to provide benefits for employees who have been impacted by statutory limits under the provisions of the qualified pension and savings plan. Employees in this plan are subject to the vesting requirements of the underlying qualified plans. Deferred Compensation Plan. A deferred compensation plan is maintained by CME, under which eligible employees and members of the board of directors may contribute a percentage of their compensation and defer income taxes thereon until the time of distribution. COMEX Members' Retirement Plan and Benefits. COMEX maintains a non-qualified retirement and benefit plan under the COMEX Members' Recognition and Retention Plan (MRRP). This plan provides benefits to certain members of the COMEX division based on long-term membership, and participation is limited to individuals who were COMEX division members prior to NYMEX's acquisition of COMEX in 1994. No new participants were permitted into the plan after the date of this acquisition. All benefits to be paid under the MRRP are based on reasonable actuarial assumptions which are based upon the amounts that are available and are expected to be available to pay benefits. Total contributions to the plan were $2.0 million in 2015 and $0.8 million for each of the years 2014 and 2013. At December 31, 2015 and 2014 , the obligation for the MRRP totaled $19.9 million and $21.2 million , respectively. Assets with a fair value of $22.0 million and $20.0 million have been allocated to this plan at December 31, 2015 and 2014 , respectively, and are included in marketable securities and cash and cash equivalents in the consolidated balance sheets. The balances in this plan are subject to the claims of general creditors of COMEX.

Commitments

Commitments	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments	COMMITMENTS Operating Leases. CME Group has entered into various non-cancellable operating lease agreements, with the most significant being as follows: • In November 2013, the company sold a building in New York and leased back a portion of the property. The operating lease, which has an initial lease term ending on December 31, 2028, contains two consecutive renewal options for five years. • In April 2012, the company sold two buildings in Chicago at 141 W. Jackson and leased back a portion of the property. The operating lease, which has an initial lease term ending on April 30, 2027, contains four consecutive renewal options for five years. • In January 2011, the company entered into an operating lease for office space in London. The initial lease term, which became effective on January 20, 2011, terminates on March 24, 2026, with an option to terminate without penalty in January 2021. • In July 2008, the company renegotiated the operating lease for its headquarters at 20 South Wacker Drive in Chicago. The lease, which has an initial term ending on November 30, 2022, contains two consecutive renewal options for seven and ten years and a contraction option which allows the company to reduce its occupied space after November 30, 2018. In addition, the company may exercise a lease expansion option in December 2017. • In August 2006, the company entered into an operating lease for additional office space in Chicago. The initial lease term, which became effective on August 10, 2006, terminates on November 30, 2023. The lease contains two 5 -year renewal options beginning in 2023. At December 31, 2015 , future minimum payments under non-cancellable operating leases were payable as follows (in millions): Year 2016 $ 50.2 2017 44.3 2018 45.1 2019 44.8 2020 42.1 Thereafter 182.8 Total $ 409.3 Total rental expense, including equipment rental, was $54.8 million in 2015 , $51.0 million in 2014 and $28.6 million in 2013 . Other Commitments. Commitments include material contractual purchase obligations that are non-cancellable. Purchase obligations relate to advertising, licensing, hardware, software and maintenance as well as telecommunication services. At December 31, 2015 , future minimum payments due under purchase obligations were payable as follows (in millions): Year 2016 $ 10.7 2017 10.2 2018 9.7 2019 1.4 2020 0.7 Thereafter 1.4 Total $ 34.1

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Contingencies	CONTINGENCIES Legal and Regulatory Matters. In 2008, Fifth Market, Inc. (Fifth Market) filed a complaint against CME Group and CME in the Delaware District Court seeking a permanent injunction against CME's Globex system and unquantified enhanced damages for what the plaintiff alleges is willful infringement of two patents, in addition to costs, expenses and attorneys' fees. Since the complaint was filed, CME filed multiple reexaminations and reviews of the two patents at the U.S. Patent and Trademark Office (USPTO). In these proceedings, the USPTO cancelled the vast majority of the patent claims. All of the reexaminations are final and not appealable. Of the reviews, one review is still pending at the USPTO and two are on appeal to the Court of Appeals for the Federal Circuit. Based on its investigation to date and advice from legal counsel, the company believes this suit is without merit and continues to defend itself vigorously against these charges. This matter involves an alleged infringement of intellectual property which, due to its nature, involves a potential liability that is uncertain, difficult to quantify and involves a wide range of potential outcomes. We expect the reviews by the USPTO and any appeals thereof, to result in a determination of the validity of the patents at issue which we expect will have an impact on the merits of the matter. Given the uncertainty of factors which may potentially impact the resolution of the matter, at this time the company is unable to estimate the reasonably possible loss or range of reasonably possible loss in the unlikely event it were found to be liable at trial in the matter. In 2013, the CFTC filed suit against NYMEX and two former employees alleging disclosure of confidential customer information in violation of the Commodity Exchange Act. NYMEX’s motion to dismiss was denied in 2014. Based on its investigation to date and advice from legal counsel, the company believes that it has strong factual and legal defenses to the claim. In the normal course of business, the company discusses matters with its regulators raised during regulatory examinations or otherwise subject to their inquiry and oversight. These matters could result in censures, fines, penalties or other sanctions. Management believes the outcome of any resulting actions will not have a material impact on its consolidated financial position or results of operations. However, the company is unable to predict the outcome or the timing of the ultimate resolution of these matters, or the potential fines, penalties or injunctive or other equitable relief, if any, that may result from these matters. In addition, the company is a defendant in, and has potential for, various other legal proceedings arising from its regular business activities. While the ultimate results of such proceedings against the company cannot be predicted with certainty, the company believes that the resolution of any of these matters on an individual basis will not have a material impact on its consolidated financial position or results of operations. At December 31, 2015 and 2014 , the company had accrued $3.5 million and $4.3 million , respectively, for legal and regulatory matters that were probable and estimable. Intellectual Property Indemnifications. Certain agreements with customers and other third parties related to accessing the CME platforms, utilizing market data services and licensing CME SPAN software may contain indemnifications from intellectual property claims that may be made against them as a result of their use of the applicable products and/or services. The potential future claims relating to these indemnifications cannot be estimated and therefore no liability has been recorded.

Guarantees

Guarantees	12 Months Ended
	Dec. 31, 2015
Guarantees [Abstract]
Guarantees	GUARANTEES Mutual Offset Agreement. CME and Singapore Exchange Limited (SGX) have a mutual offset agreement with a current term through October 2016. This agreement enables market participants to open a futures position on one exchange and liquidate it on the other. The term of the agreement will automatically renew for a one-year period unless either party provides advance notice of its intent to terminate. CME can maintain collateral in the form of U.S. Treasury securities or irrevocable, standby letters of credit. At December 31, 2015 , CME was contingently liable to SGX on irrevocable letters of credit totaling $610.0 million . Regardless of the collateral, CME guarantees all cleared transactions submitted through SGX and would initiate procedures designed to satisfy these financial obligations in the event of a default, such as the use of performance bonds and guaranty fund contributions of the defaulting clearing firm. The company believes that its guarantee liability is immaterial and therefore has not recorded any liability at December 31, 2015 . Family Farmer and Rancher Protection Fund. In 2012, the company established the Family Farmer and Rancher Protection Fund (the Fund). The Fund is designed to provide payments, up to certain maximum levels, to family farmers, ranchers and other agricultural industry participants who use the company's agricultural products and who suffer losses to their segregated account balances due to their CME clearing member becoming insolvent. Under the terms of the Fund, farmers and ranchers are eligible for up to $25,000 per participant. Farming and ranching cooperatives are eligible for up to $100,000 per cooperative. The Fund has an aggregate maximum payment amount of $100.0 million . Since its establishment, the Fund has made payments of approximately $2.0 million , which leaves $98.0 million available for future claims. If payments to participants were to exceed this amount, payments would be pro-rated. Clearing members and customers must register in advance with the company and provide certain documentation in order to substantiate their eligibility. The company believes that its guarantee liability is immaterial and therefore has not recorded any liability at December 31, 2015 .

Redeemable Non-Controlling Inte

Redeemable Non-Controlling Interest	12 Months Ended
	Dec. 31, 2015
Temporary Equity [Abstract]
Redeemable Non-controlling Interest	REDEEMABLE NON-CONTROLLING INTEREST The following summarizes the changes in redeemable non-controlling interest for the year ended December 31, 2013. Non-controlling interests that do not contain redemption features are presented in the statements of equity. (in millions) 2013 Balance at January 1 $ 80.8 Total comprehensive income attributable to redeemable non-controlling interest 1.5 Purchase of non-controlling interest (82.3 ) Balance at December 31 $ — In April 2013, the company purchased the remaining 10% non-controlling interest in its business venture with Dow Jones & Company for $80.0 million . Prior to the purchase, the company maintained a 24.4% interest in S&P/DJI. As a result of the purchase of the non-controlling interest, the company's interest in S&P/DJI increased to 27% . The company recognized a $165.6 million tax benefit through additional paid-in capital. The tax benefit was due to a reduction in deferred tax liabilities related to the tax basis in CME Group Index Holdings LLC. The company also recognized a $2.3 million gain through additional paid-in capital related to the purchase of the non-controlling interest.

Capital Stock

Capital Stock	12 Months Ended
	Dec. 31, 2015
Capital Stock [abstract]
Capital Stock	CAPITAL STOCK Shares Outstanding. The following table presents information regarding capital stock: December 31, (in thousands) 2015 2014 Class A common stock authorized 1,000,000 1,000,000 Class A common stock issued and outstanding 336,938 335,452 Class B-1 common stock authorized, issued and outstanding 0.6 0.6 Class B-2 common stock authorized, issued and outstanding 0.8 0.8 Class B-3 common stock authorized, issued and outstanding 1.3 1.3 Class B-4 common stock authorized, issued and outstanding 0.4 0.4 CME Group has no shares of preferred stock issued and outstanding. Associated Trading Rights. Members of CME, CBOT, NYMEX and COMEX own or lease trading rights which entitle them to access the trading floors, discounts on trading fees and the right to vote on certain exchange matters as provided for by the rules of the particular exchange and CME Group's or the subsidiaries' organizational documents. Each class of CME Group Class B common stock is associated with a membership in a specific division for trading at CME. A CME trading right is a separate asset that is not part of or evidenced by the associated share of Class B common stock of CME Group. The Class B common stock of CME Group is intended only to ensure that the Class B shareholders of CME Group retain rights with respect to representation on the board of directors and approval rights with respect to the core rights described below. Trading rights at CBOT are evidenced by Class B memberships in CBOT, at NYMEX by Class A memberships in NYMEX and at COMEX by COMEX Division Memberships. Members of CBOT, NYMEX and COMEX do not have any rights to elect members of the board of directors and are not entitled to receive dividends or other distributions on their memberships or trading permits. Core Rights. Holders of CME Group Class B common shares have the right to approve changes in specified rights relating to the trading privileges at CME associated with those shares. These core rights relate primarily to trading right protections, certain trading fee protections and certain membership benefit protections. Votes on changes to these core rights are weighted by class. Each class of Class B common stock has the following number of votes on matters relating to core rights: Class B-1, six votes per share; Class B-2, two votes per share; Class B-3, one vote per share; and Class B-4, 1/6 th of one vote per share. The approval of a majority of the votes cast by the holders of shares of Class B common stock is required in order to approve any changes to core rights. Holders of shares of Class A common stock do not have the right to vote on changes to core rights. Voting Rights. With the exception of the matters reserved to holders of CME Group Class B common stock, holders of CME Group common stock vote together on all matters for which a vote of common shareholders is required. In these votes, each holder of shares of Class A or Class B common stock of CME Group has one vote per share. Transfer Restrictions. Each class of CME Group Class B common stock is subject to transfer restrictions contained in the Certificate of Incorporation of CME Group. These transfer restrictions prohibit the sale or transfer of any shares of Class B common stock separate from the sale of the associated trading rights. Election of Directors. The CME Group Board of Directors is currently comprised of 24 members. Holders of Class B-1, Class B-2 and Class B-3 common stock have the right to elect six directors, of which three are elected by Class B-1 shareholders, two are elected by Class B-2 shareholders and one is elected by Class B-3 shareholders. The remaining directors are elected by the Class A and Class B shareholders voting as a single class. Dividends. Holders of Class A and Class B common stock of CME Group are entitled to receive proportionately such dividends, if any, as may be declared by the CME Group board of directors. CME Group Omnibus Stock Plan. CME Group has adopted an Omnibus Stock Plan under which stock-based awards may be made to employees. A total of 40.2 million Class A common stock shares have been reserved for awards under the plan. Awards totaling 23.3 million shares have been granted and are outstanding or have been exercised under this plan at December 31, 2015 (note 17). CBOT Holdings Long-Term Equity Incentive Plan. In connection with the merger with CBOT Holdings, CME Group assumed CBOT Holdings' 2005 Long-Term Equity Incentive Plan. Under the plan, stock-based awards may be made to certain directors, officers and other key employees or individuals. A total of 2.3 million shares were reserved for awards under the plan. In connection with receiving shareholder approval to increase the amount of authorized shares under the CME Group Omnibus Stock Plan in May 2009, the company undertook to freeze future awards under this plan. The plan terminated during 2015 and, as a result, the remaining shares authorized for future awards expired. NYMEX Holdings Omnibus Long-Term Incentive Plan. In connection with the merger with NYMEX Holdings, CME Group assumed NYMEX Holdings' 2006 Omnibus Long-Term Incentive Plan (NYMEX Omnibus Stock Plan). Under the plan, stock-based awards may be made to any director, officer or employee of the company and other key individuals providing services to the company. A total of 5.0 million shares have been reserved for awards under the plan. In connection with receiving shareholder approval to increase the amount of authorized shares under the CME Group Omnibus Stock Plan in May 2009, the company undertook to freeze future awards under this plan. As a result, 3.6 million shares that remained authorized for future awards under this plan were frozen. Director Stock Plan. CME Group has adopted a Director Stock Plan under which awards are made to non-executive directors as part of their annual compensation. A total of 625,000 Class A shares have been reserved under this plan, and approximately 320,000 shares have been awarded through December 31, 2015 . Employee Stock Purchase Plan. CME Group has adopted an Employee Stock Purchase Plan (ESPP) under which employees may purchase Class A shares at 90% of the market value of the shares using after-tax payroll deductions. A total of 500,000 Class A shares have been reserved under this plan, of which approximately 220,000 shares have been purchased through December 31, 2015 (note 17).

Stock-Based Payments

Stock-Based Payments	12 Months Ended
	Dec. 31, 2015
Share-based Compensation [Abstract]
Stock-Based Payments	STOCK-BASED PAYMENTS CME Group adopted an Omnibus Stock Plan under which stock-based awards may be made to employees. A total of 40.2 million Class A shares have been reserved for awards under the plan. Awards totaling 23.3 million shares have been granted and are outstanding or have been exercised under the plan as of December 31, 2015 . Awards granted generally vest over a four -year period, with 25% vesting one year after the grant date and on that same date in each of the following three years. Total compensation expense for stock-based payments and total income tax benefit recognized in the consolidated statements of income for stock-based awards were as follows: (in millions) 2015 2014 2013 Compensation expense $ 61.0 $ 55.0 $ 54.4 Income tax benefit recognized 32.4 19.5 20.0 Excluding estimates of future forfeitures, at December 31, 2015 , there was $94.9 million of total unrecognized compensation expense related to employee stock-based compensation arrangements that had not yet vested. This expense is expected to be recognized over a weighted average period of 2.2 years. Stock options have not been granted since 2012. The following table summarizes stock option activity for 2015 . Aggregate intrinsic value is in millions. Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (in years) Aggregate Intrinsic Value Outstanding at December 31, 2014 3,011,267 $ 72 3.7 $ 60.1 Exercised (984,581 ) 65 Cancelled (212,635 ) 101 Outstanding at December 31, 2015 1,814,051 73 3.3 38.7 Exercisable at December 31, 2015 1,812,746 73 3.3 38.6 The total intrinsic value of options exercised during 2015 , 2014 and 2013 was $29.5 million , $29.5 million and $35.3 million , respectively. In 2015 , the company granted 574,453 shares of restricted Class A common stock and 7,392 shares of restricted stock units. Restricted common stock and restricted stock units generally have a vesting period of two to four years. The fair value related to these grants was $55.5 million , which is recognized as compensation expense on an accelerated basis over the vesting period. Beginning with restricted stock grants in September 2010, dividends are accrued on restricted Class A common stock and restricted stock units and are paid once the restricted stock vests. In 2015 , the company also granted 122,317 performance shares. The fair value related to these grants was $12.3 million , which is recognized as compensation expense on an accelerated and straight-lined basis over the vesting period. The vesting of these shares is contingent on meeting stated performance or market conditions. The following table summarizes restricted stock, restricted stock units, and performance shares activity for 2015 : Number of Shares Weighted Average Grant Date Fair Value Outstanding at December 31, 2014 2,098,308 $ 72 Granted 704,162 96 Vested (456,153 ) 67 Cancelled (424,019 ) 70 Outstanding at December 31, 2015 1,922,298 83 The total fair value of restricted stock, restricted stock units, and performance shares that vested during 2015 , 2014 and 2013 was $43.3 million , $40.5 million and $31.9 million , respectively. Eligible employees may acquire shares of Class A common stock using after-tax payroll deductions made during consecutive offering periods of approximately six months in duration. Shares are purchased at the end of each offering period at a price of 90% of the closing price of the Class A common stock as reported on the NASDAQ Global Select Market. Compensation expense is recognized on the dates of purchase for the discount from the closing price. In 2015 , 2014 and 2013 , a total of 19,756 , 23,678 and 18,632 shares, respectively, of Class A common stock were issued to participating employees. These shares are subject to a six-month holding period. Annual expense of $0.2 million , $0.2 million and $0.1 million for the purchase discount was recognized in 2015 , 2014 and 2013 , respectively. Non-executive directors receive an annual award of Class A common stock with a value equal to $100,000 . Non-executive directors may also elect to receive some or all of the cash portion of their annual stipend, up to $60,000 , in shares of stock based on the closing price at the date of distribution. As a result, 25,853 , 33,735 and 27,168 shares of Class A common stock were issued to non-executive directors during 2015 , 2014 and 2013 , respectively. These shares are not subject to any vesting restrictions. Expense of $2.5 million , $2.1 million and $2.1 million related to these stock-based payments was recognized for the years ended December 31, 2015 , 2014 and 2013 , respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Comprehensive Income (Loss) Note [Text Block]	ACCUMULATED OTHER COMPREHENSIVE INCOME The following tables present changes in the accumulated balances for each component of other comprehensive income attributable to CME Group, including current period other comprehensive income and reclassifications out of accumulated other comprehensive income: (in millions) Investment Securities Defined Benefit Plans Derivative Investments Foreign Currency Translation Total Balance at December 31, 2014 $ (22.9 ) $ (31.3 ) $ 62.6 $ (2.2 ) $ 6.2 Other comprehensive income before reclassifications and income tax benefit (expense) (78.0 ) (11.2 ) (4.7 ) (10.6 ) (104.5 ) Amounts reclassified from accumulated other comprehensive income 8.5 2.7 0.6 — 11.8 Income tax benefit (expense) (2.6 ) 3.2 1.1 4.0 5.7 Net current period other comprehensive income attributable to CME Group (72.1 ) (5.3 ) (3.0 ) (6.6 ) (87.0 ) Balance at December 31, 2015 $ (95.0 ) $ (36.6 ) $ 59.6 $ (8.8 ) $ (80.8 ) (in millions) Investment Securities Defined Benefit Plans Derivative Investments Foreign Currency Translation Total Balance at December 31, 2013 $ 98.9 $ (12.8 ) $ 65.0 $ 0.9 $ 152.0 Other comprehensive income before reclassifications and income tax benefit (expense) (116.6 ) (30.0 ) (2.3 ) (5.2 ) (154.1 ) Amounts reclassified from accumulated other comprehensive income — 0.3 (1.5 ) — (1.2 ) Income tax benefit (expense) (5.2 ) 11.2 1.4 2.1 9.5 Net current period other comprehensive income attributable to CME Group (121.8 ) (18.5 ) (2.4 ) (3.1 ) (145.8 ) Balance at December 31, 2014 $ (22.9 ) $ (31.3 ) $ 62.6 $ (2.2 ) $ 6.2 (in millions) Investment Securities Defined Benefit Plans Derivative Investments Foreign Currency Translation Total Balance at December 31, 2012 $ 256.7 $ (32.4 ) $ (16.4 ) $ 1.4 $ 209.3 Other comprehensive income before reclassifications and income tax benefit (expense) (221.0 ) 28.4 128.8 (0.8 ) (64.6 ) Amounts reclassified from accumulated other comprehensive income (0.7 ) 3.2 1.6 — 4.1 Income tax benefit (expense) 63.9 (12.0 ) (49.0 ) 0.3 3.2 Net current period other comprehensive income attributable to CME Group (157.8 ) 19.6 81.4 (0.5 ) (57.3 ) Balance at December 31, 2013 $ 98.9 $ (12.8 ) $ 65.0 $ 0.9 $ 152.0

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The company uses a three-level classification hierarchy of fair value measurements for disclosure purposes. • Level 1 inputs, which are considered the most reliable evidence of fair value, consist of quoted prices (unadjusted) for identical assets or liabilities in active markets. • Level 2 inputs consist of observable market data, other than level 1 inputs, such as quoted prices for similar assets and liabilities in active markets or inputs other than quoted prices that are directly observable. • Level 3 inputs consist of unobservable inputs which are derived and cannot be corroborated by market data or other entity-specific inputs. Level 1 assets generally include U.S. Treasury securities and investments in publicly traded mutual funds with quoted market prices. In general, the company uses quoted prices in active markets for identical assets to determine the fair value of marketable securities and equity investments. If quoted prices are not available to determine fair value, the company uses other inputs that are directly observable. Assets and liabilities included in level 2 generally consist of asset-backed securities and interest rate swap contracts. Asset-backed securities were measured at fair value based on matrix pricing using prices of similar securities with similar inputs such as maturity dates, interest rates and credit ratings. The company determined the fair value of its interest rate swap contracts using standard valuation models with market-based observable inputs including forward and spot exchange rates and interest rate curves. The company determined the fair value of its contingent consideration liability, considered a level 3 liability, using a discounted cash flow model to calculate the present value of future payouts. The liability was included in level 3 because management used significant unobservable inputs, including a discount rate of 20% and payout probability of 100% . Significant increases or decreases in any of those inputs in isolation would result in a significantly different fair value. Financial assets and liabilities recorded in the consolidated balance sheet as of December 31, 2015 and 2014 were classified in their entirety based on the lowest level of input that was significant to each asset or liability's fair value measurement. Financial Instruments Measured at Fair Value on a Recurring Basis: December 31, 2015 (in millions) Level 1 Level 2 Level 3 Total Assets at Fair Value: Marketable securities: U.S. Treasury securities $ 16.2 $ — $ — $ 16.2 Mutual funds 55.9 — — 55.9 Equity securities 0.1 — — 0.1 Asset-backed securities — 0.3 — 0.3 Total 72.2 0.3 — 72.5 Performance bonds and guaranty fund contributions: U.S. Treasury securities (1) 10,973.9 — — 10,973.9 Equity investments 214.5 — — 214.5 Total Assets at Fair Value $ 11,260.6 $ 0.3 $ — $ 11,260.9 Liabilities at Fair Value: Contingent consideration $ — $ — $ 0.3 $ 0.3 Total Liabilities at Fair Value $ — $ — $ 0.3 $ 0.3 December 31, 2014 (in millions) Level 1 Level 2 Level 3 Total Assets at Fair Value: Marketable securities: U.S. Treasury securities $ 19.1 $ — $ — $ 19.1 Mutual funds 55.1 — — 55.1 Equity securities 0.1 — — 0.1 Asset-backed securities — 0.4 — 0.4 Total 74.3 0.4 — 74.7 Performance bonds and guaranty fund contributions: U.S. Treasury securities (1) 16,699.7 — — 16,699.7 Equity investments 432.1 — — 432.1 Total Assets at Fair Value $ 17,206.1 $ 0.4 $ — $ 17,206.5 Liabilities at Fair Value: Interest rate swap contracts $ — $ 2.3 $ — $ 2.3 Contingent consideration — — 17.7 17.7 Total Liabilities at Fair Value $ — $ 2.3 $ 17.7 $ 20.0 (1) Performance bonds and guaranty fund contributions on the consolidated balance sheet at December 31, 2015 and 2014 include cash collateral that has been invested in U.S. Treasury securities. There were no transfers of assets between level 1, level 2 and level 3 during 2015 and 2014 . There were no level 3 assets valued at fair value on a recurring basis during 2015 and 2014 . The following is a reconciliation of level 3 liabilities valued at fair value on a recurring basis during 2015 and 2014 . (in millions) Contingent Consideration Fair value of liability at December 31, 2013 $ 15.7 Realized and unrealized gains (losses): Included in other expense 7.1 Settlements (5.1 ) Fair value of liability at December 31, 2014 17.7 Realized and unrealized gains (losses): Included in other expense 1.3 Settlements (18.7 ) Fair value of liability at December 31, 2015 $ 0.3 There were no level 3 assets or liabilities valued at fair value on a nonrecurring basis during 2015 and 2014. The fair values of the fixed-rate notes due 2022, 2025 and 2043, which are classified as level 2 under the fair value hierarchy, were estimated using quoted market prices. At December 31, 2015 , the fair values of the fixed-rate notes by maturity date were as follows: (in millions) Fair Value $750.0 million fixed rate notes due September 2022, stated rate of 3.00% $ 758.4 $750.0 million fixed rate notes due March 2025, stated rate of 3.00% 743.3 $750.0 million fixed rates notes due September 2043, stated rate of 5.30% 856.3

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE Basic earnings per share is computed by dividing net income attributable to CME Group by the weighted average number of shares of all classes of common stock outstanding for each reporting period. Diluted earnings per share reflects the increase in shares using the treasury stock method to reflect the impact of an equivalent number of shares of common stock if stock options were exercised and restricted stock awards were converted into common stock. Anti-dilutive stock options and stock awards were as follows for the years presented: (in thousands) 2015 2014 2013 Stock options 420 1,330 1,566 Stock awards 115 124 65 Total 535 1,454 1,631 The following table presents the earnings per share calculation for the years presented: 2015 2014 2013 Net Income Attributable to CME Group (in millions) $ 1,247.0 $ 1,127.1 $ 976.8 Weighted Average Common Shares Outstanding (in thousands): Basic 336,224 334,409 332,678 Effect of stock options and stock awards 1,670 1,654 1,720 Diluted 337,894 336,063 334,398 Earnings per Common Share Attributable to CME Group: Basic $ 3.71 $ 3.37 $ 2.94 Diluted 3.69 3.35 2.92

Quarterly Information (Unaudite

Quarterly Information (Unaudited)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Data [Abstract]
Quarterly Information	QUARTERLY INFORMATION (UNAUDITED) (in millions, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Year to Date Year Ended December 31, 2015 Total revenues $ 842.7 $ 820.0 $ 850.3 $ 813.8 $ 3,326.8 Operating income 507.3 495.1 516.4 469.9 1,988.7 Non-operating income (expense) 16.5 (47.0 ) — (1.4 ) (31.9 ) Income before income taxes 523.8 448.1 516.4 468.5 1,956.8 Net income attributable to CME Group 330.4 265.0 359.9 291.7 1,247.0 Earnings per common share attributable to CME Group: Basic $ 0.98 $ 0.79 $ 1.07 $ 0.87 $ 3.71 Diluted 0.98 0.78 1.06 0.86 3.69 Year Ended December 31, 2014 Total revenues $ 777.4 $ 731.6 $ 762.4 $ 841.1 $ 3,112.5 Operating income 454.5 412.0 430.4 471.5 1,768.4 Non-operating income (expense) (8.1 ) 10.1 (1.3 ) 2.3 3.0 Income before income taxes 446.4 422.1 429.1 473.8 1,771.4 Net income attributable to CME Group 266.8 263.8 290.0 306.5 1,127.1 Earnings per common share attributable to CME Group: Basic $ 0.80 $ 0.79 $ 0.87 $ 0.91 $ 3.37 Diluted 0.79 0.79 0.86 0.91 3.35

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS The company has evaluated subsequent events through the date the financial statements were issued. The company has determined that there were no subsequent events that require disclosure.

Schedule II_Valuation and Quali

Schedule II—Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2015
Valuation and Qualifying Accounts [Abstract]
Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]	CME Group Inc. and Subsidiaries Schedule II—Valuation and Qualifying Accounts For the Years Ended December 31, 2015 , 2014 and 2013 (dollars in millions) Balance at beginning of year Charged against goodwill Charged (credited) to costs and expenses Other (1) Balance at end of year Year Ended December 31, 2015 Allowance for doubtful accounts $ 1.2 $ — $ 1.1 $ (0.4 ) $ 1.9 Allowance for deferred tax assets 99.2 — (2.4 ) 25.5 122.3 Year Ended December 31, 2014 Allowance for doubtful accounts $ 1.2 $ — $ 0.1 $ (0.1 ) $ 1.2 Allowance for deferred tax assets 47.5 — — 51.7 99.2 Year Ended December 31, 2013 Allowance for doubtful accounts $ 0.8 $ — $ 0.8 $ (0.4 ) $ 1.2 Allowance for deferred tax assets 24.8 — 4.6 18.1 47.5 _______________ (1) Includes write-offs of doubtful accounts and reversals of deferred tax asset valuation allowances against accumulated other comprehensive income.

Summary of Significant Accoun32

Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Principles of Consolidation	Basis of Presentation. The accompanying consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States and include the accounts of the company and its majority-owned subsidiaries. All intercompany transactions and balances have been eliminated.
Use of Estimates	Use of Estimates. The preparation of consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts and the disclosure of contingent amounts in the consolidated financial statements and accompanying notes. Estimates are based on historical experience, where applicable, and assumptions management believes are reasonable under the circumstances. Due to the inherent uncertainty involved with estimates, actual results may differ.
Cash and Cash Equivalents	Cash and Cash Equivalents. Cash and cash equivalents consist of cash and highly liquid investments with a maturity of three months or less at the time of purchase.
Investment, Policy [Policy Text Block]	Financial Investments. The company maintains short-term and long-term investments, classified as available-for-sale or trading securities. Available-for-sale investments are carried at their fair value, with unrealized gains and losses, net of deferred income taxes, reported as a component of accumulated other comprehensive income. Trading securities held in connection with non-qualified deferred compensation plans are recorded at fair value, with net realized and unrealized gains and losses and dividend income reported as investment income. Also, the company maintains long-term investments accounted for under the cost method and equity method, depending upon the degree of influence over the investee as held by the company. The company reviews its investments to determine whether a decline in fair value below the cost basis is other-than-temporary. If events and circumstances indicate that a decline in the value of the assets has occurred and is deemed to be other-than-temporary, the carrying value of the investments is reduced to its fair value and a corresponding impairment is charged to earnings.
Fair Value of Financial Instruments	Fair Value of Financial Instruments. The company uses a three-level classification hierarchy of fair value measurements that establishes the quality of inputs used to measure fair value. The fair value of a financial instrument is the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value of financial instruments is determined using various techniques that involve some level of estimation and judgment, the degree of which is dependent on the price transparency and the complexity of the instruments.
Derivative Investments	Derivative Investments. The company uses derivative instruments, designated as cash flow hedges, to limit exposure to changes in interest rates. Derivatives are recorded at fair value in the consolidated balance sheets. The effective portion of the changes in the fair value of cash flow hedges is deferred in accumulated other comprehensive income. Any realized gains and losses from effective hedges are classified as interest expense in the consolidated statements of income, and any ineffective or excluded portion of a hedge is recognized in earnings immediately.
Accounts Receivable	Accounts Receivable. Accounts receivable are comprised of trade receivables and unbilled revenue including clearing and transaction fees and market data and information services revenue. All accounts receivable are stated at cost. Exposure to losses on receivables for clearing and transaction fees and other amounts owed by clearing firms is dependent on each clearing firm's financial condition and the memberships that collateralize fees owed to the exchange. The exchange retains the right to liquidate exchange memberships to satisfy a clearing firm's receivable. The allowance for doubtful accounts is calculated based on historical losses and management's assessment of probable future collections.
Performance Bonds and Guaranty Fund Contributions	Performance Bonds and Guaranty Fund Contributions. Performance bonds and guaranty fund contributions held for clearing firms may be in the form of cash, securities or other non-cash deposits. Performance bonds and guaranty fund contributions received in the form of cash held by CME and CMECE may be invested in U.S. government securities and certain foreign government securities acquired through and held by a bank or broker-dealer subsidiary of a bank, reverse repurchase agreements secured with highly rated government securities, money market funds or through CME's Interest Earning Facility (IEF) program. Any interest earned on CME investments accrues to CME and is included in investment income in the consolidated statements of income. CME and CMECE may distribute any interest earned on CME and CMECE investments to the clearing firms at their discretion. Because CME and CMECE have control of the cash collateral and the benefits and risks of ownership accrue to CME and CMECE, cash performance bonds and guaranty fund contributions are reflected in the consolidated balance sheets. Performance bonds and guaranty fund contributions assets on the consolidated balance sheets also include U.S. Treasury securities with maturity dates of 90 days or less. U.S. Treasury securities are purchased by CME, at its discretion, using cash collateral. Securities and other non-cash deposits may include U.S. Treasury securities, U.S. government agency securities, Eurobonds, corporate bonds, other foreign government securities and gold bullion. Securities and other non-cash deposits are held in safekeeping by a custodian bank. Interest and gains or losses on securities deposited to satisfy performance bond and guaranty fund requirements accrue to the clearing firm. Because the benefits and risks of ownership accrue to the clearing firm, non-cash performance bonds and guaranty fund contributions are not reflected in the consolidated balance sheets.
Property, Equipment and Leasehold Improvements	Property, Equipment and Leasehold Improvements. Property, equipment and leasehold improvements are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization are calculated using the straight-line method, generally over two to thirty-nine years. Property and equipment are depreciated over their estimated useful lives. Leasehold improvements are amortized over the shorter of the remaining term of the respective lease to which they relate or the remaining useful life of the leasehold improvement. Land is reported at cost. Internal and external costs incurred in developing or obtaining computer software for internal use are capitalized and amortized on a straight-line basis over the estimated useful life of the software, generally two to four years.
Operating Leases	Operating Leases. All leases in which the company is the tenant are accounted for as operating leases. Landlord allowances are recorded as a reduction to rent expense on a straight-line basis over the term of the lease.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets. Goodwill represents the excess of the purchase price over the fair value of the net assets acquired in a business combination. The company reviews goodwill and indefinite-lived intangible assets for impairment at least annually and whenever events or circumstances indicate that their carrying values may not be recoverable. The company may test goodwill quantitatively for impairment by comparing the carrying value of a reporting unit to its estimated fair value. Estimating the fair value of a reporting unit involves significant judgments inherent in the analysis including estimating the amount and timing of future cash flows and the selection of appropriate discount rates and long-term growth rate assumptions. Changes in these estimates and assumptions could materially affect the determination of fair value of the reporting unit. If the carrying amount exceeds fair value, impairment is recorded. In certain circumstances, goodwill may be reviewed qualitatively for indications of impairment without utilizing valuation techniques to estimate fair value. The company evaluates the recoverability of indefinite-lived intangible assets by comparing the estimated fair value of the intangible asset to its carrying value. If the indefinite-lived intangible asset carrying value exceeds its fair value, an impairment loss is recognized in an amount equal to that excess. Estimating the fair value of indefinite-lived intangible assets involves the use of valuation techniques that rely on significant estimates and assumptions including forecasted revenue growth rates, forecasted allocations of expense and risk-adjusted discount rates. Changes in these estimates and assumptions could materially affect the determination of fair value for indefinite-lived intangible assets. In certain circumstances, indefinite-lived intangible assets may be reviewed qualitatively for indications of impairment without utilizing valuation techniques to estimate fair value. Intangible assets subject to amortization are also assessed for impairment when indicated by a change in economic or operational circumstances. The impairment assessment of these assets requires management to first compare the book value of the amortizing asset to undiscounted cash flows. If the book value exceeds the undiscounted cash flows, management is then required to estimate the fair value of the assets and record an impairment loss for the excess of the carrying value over the fair value.
Business Combinations	Business Combinations. The company accounts for business combinations using the acquisition method. The method requires the acquirer to recognize the assets acquired, liabilities assumed, and any non-controlling interest in the acquiree at the acquisition date, measured at their fair values as of that date. The company may use independent valuation services to assist in determining the estimated fair values.
Employee Benefit Plans	Employee Benefit Plans. The company recognizes the funded status of defined benefit postretirement plans in its consolidated balance sheets. Changes in that funded status are recognized in the year of change in other comprehensive income (loss). Plan assets and obligations are measured at year end. The company recognizes future changes in actuarial gains and losses and prior service costs in the year in which the changes occur through other comprehensive income (loss).
Foreign Currency Translation	Foreign Currency Translation . Foreign currency denominated assets and liabilities are re-measured into the functional currency using period-end exchange rates. Gains and losses from foreign currency transactions are included in other expense in the accompanying consolidated statements of income. When the functional currency differs from the reporting currency, revenues and expenses of foreign subsidiaries are translated from their functional currencies into U.S. dollars using weighted-average exchange rates while their assets and liabilities are translated into U.S. dollars using period-end exchange rates. Gains and losses resulting from foreign currency translations are included in accumulated other comprehensive income (loss) within shareholders' equity.
Revenue Recognition	Revenue Recognition. Revenue recognition policies for specific sources of revenue are discussed below. Clearing and Transaction Fees. Clearing and transaction fees include per-contract charges for trade execution, clearing, trading on the company's electronic trading platform and other fees. Fees are charged at various rates based on the product traded, the method of trade, the exchange trading privileges of the customer making the trade and the type of contract. Clearing and transaction fees are recognized as revenue when a buy and sell order are matched and the trade is cleared. Therefore, unfilled or canceled buy and sell orders have no impact on revenue. On occasion, the customer's exchange trading privileges may not be properly entered by the clearing firm and incorrect fees are charged for the transactions. When this information is corrected within the time period allowed by the exchange, a fee adjustment is provided to the clearing firm. A reserve is established for estimated fee adjustments to reflect corrections to customer exchange trading privileges. The reserve is based on the historical pattern of adjustments processed as well as specific adjustment requests. The company believes the allowances are adequate to cover estimated adjustments. Market Data and Information Services. Market data and information services represent revenue earned for the dissemination of market information. Revenues are accrued each month based on the number of devices reported by vendors. The exchange conducts periodic examinations of the number of devices reported and assesses additional fees as necessary. On occasion, customers will pay for services in a lump sum payment; however, revenue is recognized as services are provided. Access and Communication Fees. Access fees are the connectivity charges to customers of the company's electronic trading platform that are also used by market data vendors and customers. The fees include co-location fees, access fees for the electronic trading platform, line charges and hardware rental charges and can vary depending on the type of connection provided. An additional installation fee may be charged depending on the type of service requested and a disconnection fee may also be charged if certain conditions are met. Revenue is generally recognized monthly as the service is provided. Communication fees consist of equipment rental and usage charges to customers and firms that utilize various telecommunications hubs located internationally as well as networks and services in the Chicago and New York City facilities. Revenue is billed and recognized on a monthly basis. Other Revenues. Other revenues include processing services revenue, which is revenue generated from various strategic relationships, as well as management fees earned under the IEF programs. For processing services revenue and IEF revenue, revenue is recognized as services are provided. Concentration of Revenue. One firm represented 13% of the company's clearing and transaction fees revenue in 2015 and one firm represented 12% of the company's clearing and transaction fees revenue in 2014 . One firm represented 11% and one firm represented 10% of the company's clearing and transaction fees revenue in 2013 . Should a clearing firm withdraw from the exchange, management believes that the customer portion of that firm's trading activity would likely transfer to another clearing firm. Therefore, management does not believe that the company is exposed to significant risk from the ongoing loss of revenue received from a particular clearing firm. The two largest resellers of market data represented approximately 43% of market data and information services revenue in 2015 , 44% in 2014 , and 52% in 2013 . Should one of these vendors no longer subscribe to the company's market data, management believes that the majority of that firm's customers would likely subscribe to the market data through another reseller. Therefore, management does not believe that the company is exposed to significant risk from a loss of revenue received from any particular market data reseller.
Share-Based Payments	Share-Based Payments. The company accounts for share-based payments at fair value, which is based on the grant date price of the equity awards issued. The company recognizes expense relating to stock-based compensation on an accelerated basis. As a result, the expense associated with each vesting date within a stock grant is recognized over the period of time that each portion of that grant vests. The company estimates expected forfeitures of stock grants.
Marketing Costs	Marketing Costs. Marketing costs are incurred for the production and communication of advertising as well as other marketing activities. These costs are expensed when incurred, except for costs related to the production of broadcast advertising, which are expensed when the first broadcast occurs.
Income Taxes	Income Taxes. Deferred income taxes arise from temporary differences between the tax basis and book basis of assets and liabilities. A valuation allowance is recognized if it is anticipated that some or all of a deferred tax asset may not be realized. The company accounts for uncertainty in income taxes recognized in its consolidated financial statements by using a more-likely-than-not recognition threshold based on the technical merits of the tax position taken or expected to be taken. The company classifies interest and penalties related to uncertain tax positions in income tax expense.
Segment Reporting	Segment Reporting. The company reports the results of its operations as one operating segment primarily comprised of CME, CBOT, NYMEX and COMEX. The remaining operations do not meet the thresholds for reporting separate segment information.

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2015
Marketable Securities [Abstract]
Available-for-sale securities	The amortized cost and fair value of these securities at December 31 were as follows: 2015 2014 (in millions) Amortized Cost Fair Value Amortized Cost Fair Value U.S. Treasury securities $ 16.1 $ 16.2 $ 19.1 $ 19.1 Asset-backed security 0.7 0.3 0.7 0.4 Equity securities 0.1 0.1 0.1 0.1 Total $ 16.9 $ 16.6 $ 19.9 $ 19.6
Amortized cost and fair value of marketable securities by contractual maturity	The amortized cost and fair value of the U.S. Treasury securities and asset-backed security at December 31, 2015 , by contractual maturity, were as follows: (in millions) Amortized Cost Fair Value Maturity of one year or less $ 16.1 $ 16.2 Maturity between one and five years — — Maturity between five and ten years — — Maturity greater than ten years 0.7 0.3 Total $ 16.8 $ 16.5

Performance Bonds and Guarant34

Performance Bonds and Guaranty Fund Contributions (Tables)	12 Months Ended
	Dec. 31, 2015
Performance Bonds and Guaranty Fund Contributions [Abstract]
Cash and securities held as performance bonds and guaranty fund contributions at fair value	Cash and non-cash deposits held as performance bonds and guaranty fund contributions at fair value at December 31 for CME and CMECE were as follows: 2015 2014 (in millions) Cash Non-Cash Deposits and IEF Funds Cash Non-Cash Deposits and IEF Funds Performance bonds 1 $ 33,592.8 $ 91,954.4 $ 38,729.0 $ 93,972.7 Guaranty fund contributions 1,919.2 5,290.0 1,719.9 5,699.0 Cross-margin arrangements 37.8 163.7 102.2 91.2 Performance collateral for delivery 3.2 — 15.7 2.1 Total $ 35,553.0 $ 97,408.1 $ 40,566.8 $ 99,765.0 (1) Cash performance bonds include cash collateral reinvested in U.S. Treasury securities.
Letters of credit	At December 31, these letters of credit, which are not included in the accompanying consolidated balance sheets, were as follows: (in millions) 2015 2014 Performance bonds $ 2,617.6 $ 2,441.9 Guaranty fund contributions 25.0 25.0 Cross-margin arrangements — 5.5 Performance collateral for delivery 1,208.0 950.4 Total Letters of Credit $ 3,850.6 $ 3,422.8

Property (Tables)

Property (Tables)	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment, Net [Abstract]
Summary of the Property Accounts	A summary of the property accounts at December 31 is presented below: (in millions) 2015 2014 Estimated Useful Life Land and land improvements $ 17.7 $ 17.7 10 - 20 years (1) Building and building improvements 280.8 273.5 3 - 39 years Leasehold improvements 248.5 219.1 3 - 24 years Furniture, fixtures and equipment 333.3 360.1 2 - 7 years Software and software development costs 400.0 379.5 2 - 4 years Total property 1,280.3 1,249.9 Less accumulated depreciation and amortization (788.6 ) (741.0 ) Property, net $ 491.7 $ 508.9 (1) Estimated useful life applies only to land improvements.

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Components of intangible assets	Intangible assets consisted of the following at December 31: 2015 2014 (in millions) Assigned Value Accumulated Amortization Net Book Value Assigned Value Accumulated Amortization Net Book Value Amortizable Intangible Assets: Clearing firm, market data and other customer relationships $ 2,838.8 $ (754.5 ) $ 2,084.3 $ 2,838.8 $ (658.8 ) $ 2,180.0 Technology-related intellectual property 29.4 (27.2 ) 2.2 29.4 (23.5 ) 5.9 Other 2.4 (1.0 ) 1.4 2.4 (0.9 ) 1.5 Total amortizable intangible assets $ 2,870.6 $ (782.7 ) 2,087.9 $ 2,870.6 $ (683.2 ) 2,187.4 Indefinite-Lived Intangible Assets: Trade names 450.0 450.0 Total intangible assets—other, net $ 2,537.9 $ 2,637.4 Trading products (1) $ 17,175.3 $ 17,175.3 _______________ (1) Trading products represent futures and options products acquired in our business combinations with CBOT Holdings, Inc., NYMEX Holdings, Inc. and KCBT. Clearing and transaction fees are generated through the trading of these products. These trading products, most of which have traded for decades, require authorization from the CFTC. Product authorizations from the CFTC have no term limits.
Weighted average useful life for the amortizable intangible assets	The originally assigned useful lives for the amortizable intangible assets as of December 31, 2015 are as follows: Clearing firm, market data and other customer relationships 5 - 30 years Technology-related intellectual property 4 - 5 years Other 3 - 24.5 years
Future estimated amortization expense	As of December 31, 2015 , the future estimated amortization expense related to amortizable intangible assets is expected to be as follows: (in millions) 2016 $ 96.1 2017 95.5 2018 94.7 2019 94.7 2020 94.7 Thereafter 1,612.2
Goodwill activity	Goodwill activity consisted of the following for the years ended December 31, 2015 and 2014 : (in millions) Balance at December 31, 2014 Business Combinations Divestitures Other Activity Balance at December 31, 2015 CBOT Holdings $ 5,035.7 $ — $ 30.7 $ — $ 5,066.4 NYMEX Holdings 2,462.2 — — — 2,462.2 Other 71.1 — (30.7 ) — 40.4 Total Goodwill $ 7,569.0 $ — $ — $ — $ 7,569.0 (in millions) Balance at December 31, 2013 Business Combinations Divestitures Other Activity Balance at December 31, 2014 CBOT Holdings $ 5,035.7 $ — $ — $ — $ 5,035.7 NYMEX Holdings 2,462.2 — — — 2,462.2 Other 71.1 — — — 71.1 Total Goodwill $ 7,569.0 $ — $ — $ — $ 7,569.0

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Schedule of Long-term Debt	Long-term debt consisted of the following at December 31: (in millions) 2015 2014 $612.5 million fixed rate notes due March 2018, stated rate of 4.40% (1) $ — $ 611.0 $750.0 million fixed rate notes due September 2022, stated rate of 3.00% (2) 748.4 748.2 $750.0 million fixed rate notes due March 2025, stated rate of 3.00% (3) 744.2 — $750.0 million fixed rate notes due September 2043, stated rate of 5.30% (4) 748.8 748.7 Total long-term debt $ 2,241.4 $ 2,107.9 _______________ (1) In February 2010, the company entered into a forward-starting interest rate swap agreement that modified the interest obligation associated with these notes so that the interest payable on the notes effectively became fixed at a rate of 4.46% . (2) In August 2012, the company entered into a forward-starting interest rate swap agreement that modified the interest obligation associated with these notes so that the interest payable on the notes effectively became fixed at a rate of 3.32% . (3) In December 2014, the company entered into a forward-starting interest rate swap agreement that modified the interest obligation associated with these notes so that the interest payable on the notes effectively became fixed at a rate of 3.11% . (4) In August 2012, CME Group entered into a forward-starting interest rate swap agreement that modified the interest obligation associated with these notes so that the interest payable on the notes effectively became fixed at a rate of 4.73%
Long-term debt maturities at par value	Long-term debt maturities, at par value, were as follows as of December 31, 2015 : (in millions) Par Value 2016 $ — 2017 — 2018 — 2019 — 2020 — Thereafter 2,250.0

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2015
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The fair value and location of outstanding derivative instruments in the consolidated balance sheet were as follows at December 31: (in millions) Balance Sheet Location 2015 2014 Interest rate contract Other current liabilities $ — $ 2.3
Effect of derivative instruments on the statements of Income and Shareholders' Equity	The pre-tax effect of derivative instruments on the consolidated statements of income as well as accumulated other comprehensive income (OCI) within the consolidated statements of comprehensive income and consolidated statements of shareholders' equity for the years ended December 31, 2015 and 2014 were as follows: Gains (Losses) Recognized in OCI (Effective Portion) (Gains) Losses Reclassified from Accumulated OCI (Effective Portion) Gains (Losses) Recognized in Income (Ineffective Portion) (in millions) 2015 2014 Location 2015 2014 Location 2015 2014 Interest rate contracts $ (4.7 ) $ (2.3 ) Interest and other borrowing costs $ (1.2 ) $ (1.5 ) Gains (losses) on derivative investments $ (1.8 ) $ —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Taxes on income	Income before income taxes and the income tax provision consisted of the following for the years ended December 31: (in millions) 2015 2014 2013 Income before income taxes: Domestic $ 1,927.3 $ 1,783.7 $ 1,599.2 Foreign 29.5 (12.3 ) 1.8 Total $ 1,956.8 $ 1,771.4 $ 1,601.0 Income tax provision: Current: Federal $ 554.5 $ 526.4 $ 491.9 State 81.0 36.5 128.8 Foreign 11.0 2.7 8.2 Total 646.5 565.6 628.9 Deferred: Federal 75.6 47.1 (157.6 ) State (12.0 ) 32.4 153.4 Foreign (0.3 ) (0.6 ) (1.8 ) Total 63.3 78.9 (6.0 ) Total Income Tax Provision $ 709.8 $ 644.5 $ 622.9
Reconciliation of the statutory U.S. federal income tax rate to the effective tax rate	Reconciliation of the statutory U.S. federal income tax rate to the effective tax rate is as follows: 2015 2014 2013 Statutory U.S. federal tax rate 35.0 % 35.0 % 35.0 % State taxes, net of federal benefit 3.0 1.6 4.8 Domestic production activities deduction (1.3 ) (1.4 ) (7.7 ) Increase (decrease) in domestic valuation allowance 0.1 0.1 0.6 Impact of revised state and local apportionment estimates (0.7 ) 1.1 6.6 Other, net 0.2 — (0.4 ) Effective Tax Rate 36.3 % 36.4 % 38.9 %
Deferred tax assets (liabilities)	At December 31, deferred income tax assets (liabilities) consisted of the following: (in millions) 2015 2014 Net Current Deferred Income Tax Assets: Unrealized loss on securities $ 1.1 $ 3.0 Stock-based compensation 19.1 19.2 Accrued expenses and other 7.7 2.2 Net Current Deferred Income Tax Assets $ 27.9 $ 24.4 Net Non-Current Deferred Income Tax Assets: Domestic unrealized loss on investment in BM&FBOVESPA $ 85.6 $ 101.7 Foreign losses 15.6 19.7 Domestic losses 14.1 7.3 Stock-based compensation 24.1 30.7 Deferred compensation and other benefit plans 31.8 38.1 Property 27.3 44.3 Unrealized losses on securities 14.9 16.5 Subtotal 213.4 258.3 Valuation allowance (122.3 ) (99.2 ) Total non-current deferred income tax assets 91.1 159.1 Non-Current Deferred Income Tax Liabilities: Purchased intangible assets (7,434.1 ) (7,448.2 ) Other (15.3 ) (13.6 ) Total non-current deferred income tax liabilities (7,449.4 ) (7,461.8 ) Net Non-Current Deferred Income Tax Liabilities $ (7,358.3 ) $ (7,302.7 )
Unrecognized tax benefits	The following is a summary of the company’s unrecognized tax benefits: (in millions) 2015 2014 2013 Gross unrecognized tax benefits $ 206.9 $ 187.6 $ 231.6 Unrecognized tax benefits, net of tax impacts in other jurisdictions 179.6 160.8 183.3 Unrecognized interest and penalties related to uncertain tax positions 19.5 11.0 42.5 Interest and penalties recognized in the consolidated statements of income 8.6 (12.5 ) 22.4
Reconciliation of unrecognized tax benefits	A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows: (in millions) 2015 2014 2013 Balance at January 1 $ 187.6 $ 231.6 $ 37.7 Additions based on tax positions related to the current year 20.4 30.5 26.1 Additions for tax positions of prior years 2.7 24.9 168.4 Reductions for tax positions of prior years (3.8 ) (51.8 ) (0.4 ) Reductions resulting from the lapse of statutes of limitations — — (0.2 ) Settlements with taxing authorities — (47.6 ) — Balance at December 31 $ 206.9 $ 187.6 $ 231.6

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2015
General Discussion of Pension and Other Postretirement Benefits [Abstract]
Summary of the change in projected benefit obligation	The following is a summary of the change in projected benefit obligation: (in millions) 2015 2014 Balance at January 1 $ 223.7 $ 175.7 Service cost 18.4 17.1 Interest cost 9.8 9.6 Actuarial (gain) loss (11.6 ) 30.1 Benefits paid (23.0 ) (8.8 ) Balance at December 31 $ 217.3 $ 223.7
Change in plan assets	The following is a summary of the change in fair value of plan assets: (in millions) 2015 2014 2013 Balance at January 1 $ 225.1 $ 193.6 $ 183.9 Actual return on plan assets (7.2 ) 14.3 18.1 Employer contributions 22.6 26.0 — Benefits paid (23.0 ) (8.8 ) (8.4 ) Balance at December 31 $ 217.5 $ 225.1 $ 193.6
Fair value of plan assets	The fair value of each major category of plan assets as of December 31 is indicated below. (in millions) 2015 2014 Level 2: Money market funds $ 26.5 $ 27.2 Mutual funds: Fixed income 61.6 67.2 Foreign equity 60.0 57.6 U.S. equity 59.9 63.4 Commodity 9.5 9.7 Total $ 217.5 $ 225.1
Components of net pension expenses and the assumptions used to determine the end-of-year projected benefit obligation and net pension expense in aggregate	The components of net pension expense and the assumptions used to determine the end-of-year projected benefit obligation and net pension expense in aggregate are indicated below: (in millions) 2015 2014 2013 Components of Net Pension Expense: Service cost $ 18.4 $ 17.1 $ 18.0 Interest cost 9.8 9.6 7.9 Expected return on plan assets (16.3 ) (14.0 ) (13.3 ) Recognized net actuarial loss 2.7 0.6 3.1 Net Pension Expense $ 14.6 $ 13.3 $ 15.7 Assumptions Used to Determine End-of-Year Benefit Obligation: Discount rate 4.60 % 4.20 % 5.10 % Rate of compensation increase 5.00 5.00 5.00 Cash balance interest crediting rate 4.00 4.00 4.00 Assumptions Used to Determine Net Pension Expense: Discount rate 4.20 % 5.10 % 4.10 % Rate of compensation increase 5.00 5.00 5.00 Expected return on plan assets 7.50 7.50 7.50 Interest crediting rate 4.00 4.00 4.00
Asset allocation for the plan	The asset allocation for the plan, by asset category, at December 31 was as follows: 2015 2014 Fixed income 28.3 % 29.8 % Foreign equity 27.6 25.6 U.S. equity 27.5 28.2 Money market funds 12.2 12.1 Commodity 4.4 4.3 The range of target allocation percentages for 2016 is as follows: Minimum Maximum Fixed income 33.0 % 45.0 % U.S. equity 23.5 35.0 Foreign equity 23.5 35.0 Commodity 2.0 8.0
Prior service costs and actuarial losses included in accumulated other comprehensive income (loss)	The pre-tax balance and activity of the prior service costs and actuarial losses for the pension plan, which are included in other comprehensive income (loss), for 2015 are as follows: (in millions) Prior Service Costs Actuarial Loss Balance at January 1 $ 0.1 $ 51.6 Unrecognized net loss — 11.9 Recognized as a component of net pension expense — (2.7 ) Balance at December 31 $ 0.1 $ 60.8
Anticipated benefit payments from the plan in future years	At December 31, 2015 , anticipated benefit payments from the plan in future years are as follows: (in millions) 2016 $ 14.1 2017 14.7 2018 15.6 2019 17.1 2020 18.0 2021-2025 113.8

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum payments under non-cancelable operating leases	At December 31, 2015 , future minimum payments under non-cancellable operating leases were payable as follows (in millions): Year 2016 $ 50.2 2017 44.3 2018 45.1 2019 44.8 2020 42.1 Thereafter 182.8 Total $ 409.3
Schedule of other commitments	At December 31, 2015 , future minimum payments due under purchase obligations were payable as follows (in millions): Year 2016 $ 10.7 2017 10.2 2018 9.7 2019 1.4 2020 0.7 Thereafter 1.4 Total $ 34.1

Redeemable Non-Controlling In42

Redeemable Non-Controlling Interest (Tables)	12 Months Ended
	Dec. 31, 2015
Temporary Equity [Abstract]
Changes in redeemable non-controlling interest	The following summarizes the changes in redeemable non-controlling interest for the year ended December 31, 2013. Non-controlling interests that do not contain redemption features are presented in the statements of equity. (in millions) 2013 Balance at January 1 $ 80.8 Total comprehensive income attributable to redeemable non-controlling interest 1.5 Purchase of non-controlling interest (82.3 ) Balance at December 31 $ —

Capital Stock (Tables)

Capital Stock (Tables)	12 Months Ended
	Dec. 31, 2015
Capital Stock [abstract]
Capital stock	The following table presents information regarding capital stock: December 31, (in thousands) 2015 2014 Class A common stock authorized 1,000,000 1,000,000 Class A common stock issued and outstanding 336,938 335,452 Class B-1 common stock authorized, issued and outstanding 0.6 0.6 Class B-2 common stock authorized, issued and outstanding 0.8 0.8 Class B-3 common stock authorized, issued and outstanding 1.3 1.3 Class B-4 common stock authorized, issued and outstanding 0.4 0.4

Stock-Based Payments (Tables)

Stock-Based Payments (Tables)	12 Months Ended
	Dec. 31, 2015
Share-based Compensation [Abstract]
Compensation expense for stock-based payments and total income tax benefit recognized	Total compensation expense for stock-based payments and total income tax benefit recognized in the consolidated statements of income for stock-based awards were as follows: (in millions) 2015 2014 2013 Compensation expense $ 61.0 $ 55.0 $ 54.4 Income tax benefit recognized 32.4 19.5 20.0
Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]	The following table summarizes stock option activity for 2015 . Aggregate intrinsic value is in millions. Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (in years) Aggregate Intrinsic Value Outstanding at December 31, 2014 3,011,267 $ 72 3.7 $ 60.1 Exercised (984,581 ) 65 Cancelled (212,635 ) 101 Outstanding at December 31, 2015 1,814,051 73 3.3 38.7 Exercisable at December 31, 2015 1,812,746 73 3.3 38.6
Schedule of Nonvested Share Activity [Table Text Block]	The following table summarizes restricted stock, restricted stock units, and performance shares activity for 2015 : Number of Shares Weighted Average Grant Date Fair Value Outstanding at December 31, 2014 2,098,308 $ 72 Granted 704,162 96 Vested (456,153 ) 67 Cancelled (424,019 ) 70 Outstanding at December 31, 2015 1,922,298 83

Accumulated Other Comprehensi45

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	(in millions) Investment Securities Defined Benefit Plans Derivative Investments Foreign Currency Translation Total Balance at December 31, 2014 $ (22.9 ) $ (31.3 ) $ 62.6 $ (2.2 ) $ 6.2 Other comprehensive income before reclassifications and income tax benefit (expense) (78.0 ) (11.2 ) (4.7 ) (10.6 ) (104.5 ) Amounts reclassified from accumulated other comprehensive income 8.5 2.7 0.6 — 11.8 Income tax benefit (expense) (2.6 ) 3.2 1.1 4.0 5.7 Net current period other comprehensive income attributable to CME Group (72.1 ) (5.3 ) (3.0 ) (6.6 ) (87.0 ) Balance at December 31, 2015 $ (95.0 ) $ (36.6 ) $ 59.6 $ (8.8 ) $ (80.8 ) (in millions) Investment Securities Defined Benefit Plans Derivative Investments Foreign Currency Translation Total Balance at December 31, 2013 $ 98.9 $ (12.8 ) $ 65.0 $ 0.9 $ 152.0 Other comprehensive income before reclassifications and income tax benefit (expense) (116.6 ) (30.0 ) (2.3 ) (5.2 ) (154.1 ) Amounts reclassified from accumulated other comprehensive income — 0.3 (1.5 ) — (1.2 ) Income tax benefit (expense) (5.2 ) 11.2 1.4 2.1 9.5 Net current period other comprehensive income attributable to CME Group (121.8 ) (18.5 ) (2.4 ) (3.1 ) (145.8 ) Balance at December 31, 2014 $ (22.9 ) $ (31.3 ) $ 62.6 $ (2.2 ) $ 6.2 (in millions) Investment Securities Defined Benefit Plans Derivative Investments Foreign Currency Translation Total Balance at December 31, 2012 $ 256.7 $ (32.4 ) $ (16.4 ) $ 1.4 $ 209.3 Other comprehensive income before reclassifications and income tax benefit (expense) (221.0 ) 28.4 128.8 (0.8 ) (64.6 ) Amounts reclassified from accumulated other comprehensive income (0.7 ) 3.2 1.6 — 4.1 Income tax benefit (expense) 63.9 (12.0 ) (49.0 ) 0.3 3.2 Net current period other comprehensive income attributable to CME Group (157.8 ) 19.6 81.4 (0.5 ) (57.3 ) Balance at December 31, 2013 $ 98.9 $ (12.8 ) $ 65.0 $ 0.9 $ 152.0

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Fair value of Debt Instruments [Table Text Block]	At December 31, 2015 , the fair values of the fixed-rate notes by maturity date were as follows: (in millions) Fair Value $750.0 million fixed rate notes due September 2022, stated rate of 3.00% $ 758.4 $750.0 million fixed rate notes due March 2025, stated rate of 3.00% 743.3 $750.0 million fixed rates notes due September 2043, stated rate of 5.30% 856.3
Financial instruments measured at fair value on a recurring basis	December 31, 2015 (in millions) Level 1 Level 2 Level 3 Total Assets at Fair Value: Marketable securities: U.S. Treasury securities $ 16.2 $ — $ — $ 16.2 Mutual funds 55.9 — — 55.9 Equity securities 0.1 — — 0.1 Asset-backed securities — 0.3 — 0.3 Total 72.2 0.3 — 72.5 Performance bonds and guaranty fund contributions: U.S. Treasury securities (1) 10,973.9 — — 10,973.9 Equity investments 214.5 — — 214.5 Total Assets at Fair Value $ 11,260.6 $ 0.3 $ — $ 11,260.9 Liabilities at Fair Value: Contingent consideration $ — $ — $ 0.3 $ 0.3 Total Liabilities at Fair Value $ — $ — $ 0.3 $ 0.3 December 31, 2014 (in millions) Level 1 Level 2 Level 3 Total Assets at Fair Value: Marketable securities: U.S. Treasury securities $ 19.1 $ — $ — $ 19.1 Mutual funds 55.1 — — 55.1 Equity securities 0.1 — — 0.1 Asset-backed securities — 0.4 — 0.4 Total 74.3 0.4 — 74.7 Performance bonds and guaranty fund contributions: U.S. Treasury securities (1) 16,699.7 — — 16,699.7 Equity investments 432.1 — — 432.1 Total Assets at Fair Value $ 17,206.1 $ 0.4 $ — $ 17,206.5 Liabilities at Fair Value: Interest rate swap contracts $ — $ 2.3 $ — $ 2.3 Contingent consideration — — 17.7 17.7 Total Liabilities at Fair Value $ — $ 2.3 $ 17.7 $ 20.0
Reconciliation of assets and liabilities valued at fair value on a recurring basis using significant unobservable inputs (level 3)	The following is a reconciliation of level 3 liabilities valued at fair value on a recurring basis during 2015 and 2014 . (in millions) Contingent Consideration Fair value of liability at December 31, 2013 $ 15.7 Realized and unrealized gains (losses): Included in other expense 7.1 Settlements (5.1 ) Fair value of liability at December 31, 2014 17.7 Realized and unrealized gains (losses): Included in other expense 1.3 Settlements (18.7 ) Fair value of liability at December 31, 2015 $ 0.3

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	Anti-dilutive stock options and stock awards were as follows for the years presented: (in thousands) 2015 2014 2013 Stock options 420 1,330 1,566 Stock awards 115 124 65 Total 535 1,454 1,631
Basic and diluted earnings per share	The following table presents the earnings per share calculation for the years presented: 2015 2014 2013 Net Income Attributable to CME Group (in millions) $ 1,247.0 $ 1,127.1 $ 976.8 Weighted Average Common Shares Outstanding (in thousands): Basic 336,224 334,409 332,678 Effect of stock options and stock awards 1,670 1,654 1,720 Diluted 337,894 336,063 334,398 Earnings per Common Share Attributable to CME Group: Basic $ 3.71 $ 3.37 $ 2.94 Diluted 3.69 3.35 2.92

Quarterly Information (Unaudi48

Quarterly Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Data [Abstract]
Quarterly Information	(in millions, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Year to Date Year Ended December 31, 2015 Total revenues $ 842.7 $ 820.0 $ 850.3 $ 813.8 $ 3,326.8 Operating income 507.3 495.1 516.4 469.9 1,988.7 Non-operating income (expense) 16.5 (47.0 ) — (1.4 ) (31.9 ) Income before income taxes 523.8 448.1 516.4 468.5 1,956.8 Net income attributable to CME Group 330.4 265.0 359.9 291.7 1,247.0 Earnings per common share attributable to CME Group: Basic $ 0.98 $ 0.79 $ 1.07 $ 0.87 $ 3.71 Diluted 0.98 0.78 1.06 0.86 3.69 Year Ended December 31, 2014 Total revenues $ 777.4 $ 731.6 $ 762.4 $ 841.1 $ 3,112.5 Operating income 454.5 412.0 430.4 471.5 1,768.4 Non-operating income (expense) (8.1 ) 10.1 (1.3 ) 2.3 3.0 Income before income taxes 446.4 422.1 429.1 473.8 1,771.4 Net income attributable to CME Group 266.8 263.8 290.0 306.5 1,127.1 Earnings per common share attributable to CME Group: Basic $ 0.80 $ 0.79 $ 0.87 $ 0.91 $ 3.37 Diluted 0.79 0.79 0.86 0.91 3.35

Organization and Business (Deta

Organization and Business (Details)	12 Months Ended
	Dec. 31, 2013
Variable Interest Entity [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	51.00%

Summary of Significant Accoun50

Summary of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Clearing and transaction fees from Firm 1
Concentration Risk, Customer	1	1	1
Concentration of revenue	13.00%	12.00%	11.00%
Clearing and transaction fees from Firm 2
Concentration Risk, Customer			1
Concentration of revenue			10.00%
Market data and information services
Concentration of revenue	43.00%	44.00%	52.00%
Minimum [Member]
Estimated useful live of the assets minimum in years	2 years
Minimum [Member] | Software and software development costs
Estimated useful live of the assets minimum in years	2 years
Maximum [Member]
Estimated useful live of the assets minimum in years	39 years
Maximum [Member] | Software and software development costs
Estimated useful live of the assets minimum in years	4 years

Marketable Securities (Availabl

Marketable Securities (Available-for-Sale Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Available-for-sale Securities, Amortized Cost Basis	$ 16.9	$ 19.9
Available-for-sale Securities	16.6	19.6
US Treasury Securities [Member]
Available-for-sale Securities, Amortized Cost Basis	16.1	19.1
Available-for-sale Securities	16.2	19.1
Asset-backed Securities [Member]
Available-for-sale Securities, Amortized Cost Basis	0.7	0.7
Available-for-sale Securities	0.3	0.4
Equity Securities [Member]
Available-for-sale Securities, Amortized Cost Basis	0.1	0.1
Available-for-sale Securities	$ 0.1	$ 0.1

Marketable Securities (Amortize

Marketable Securities (Amortized Cost and Fair Value of Marketable Securities) (Details) $ in Millions	Dec. 31, 2015USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Maturity of one year or less, Amortized Cost	$ 16.1
Maturity between one and five years, Amortized Cost	0
Maturity between five and ten years, Amortized Cost	0
Maturity greater than ten years, Amortized Cost	0.7
Total, Amortized Cost	16.8
Maturity of one year or less, Fair Value	16.2
Maturity between one and five years, Fair Value	0
Maturity between five and ten years, Fair Value	0
Maturity greater than ten years, Fair Value	0.3
Total, Fair Value	$ 16.5

Marketable Securities (Narrativ

Marketable Securities (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Available-for-sale Securities	$ 16.6	$ 19.6
Trading securities fair value	55.9	$ 55.1
Asset-backed Securities [Member]
Available-for-sale Securities	0.3
Unrealized losses	$ (0.4)

Performance Bonds and Guarant54

Performance Bonds and Guaranty Fund Contributions (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)days	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Available-for-sale Securities, Amortized Cost Basis	$ 16.9	$ 19.9
Average daily clearing settlement	3,900
Available-for-sale Securities	16.6	19.6
Total principal in IEF programs	11,300	16,400
Management fees earned under the IEF programs	$ 11.3	14.9	$ 13.9
Percentage share of cross-margining collateral	50.00%
Days fully secured | days	364
Intraday settlements of cash performance bonds	$ 210.2	224.2
364-day fully secured, committed line of credit
Line of Credit Facility, Maximum Borrowing Capacity	7,000
Line of Credit, Guaranty Fund Collateral Available	6,400
Option on increase in line of credit	10,000
Revolving senior credit facility
Line of Credit Facility, Maximum Borrowing Capacity	2,300
CME Base Guaranty Fund [Member]
Corporate Contribution	100
CME IRS Guaranty Fund [Member] [Member]
Corporate Contribution	150
CME CDS Guaranty Fund [Member] [Member]
Corporate Contribution	$ 50
Working capital designated for clearance of default in over the counter credit default swap, percent	5.00%
Working capital designated for clearance of default in over the counter interest rate swap	$ 100
CMECE Commodity Fund [Member]
Corporate Contribution	52
Guaranty Fund Contributions	10.6
Minimum Corporate Contribution	20
CMECE Interest Rate Swap [Member]
Corporate Contribution	48.2
Guaranty Fund Contributions	94.9
U.S. Treasury Performance Bond [Member]
Available-for-sale Securities, Amortized Cost Basis	11,000	16,700
Available-for-sale Securities	$ 11,000	$ 16,700

Performance Bonds and Guarant55

Performance Bonds and Guaranty Fund Contributions (Cash and Securities Held as Performance Bonds and Guaranty Fund Contributions at Fair Value) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Performance collateral for delivery	$ 1,208	$ 950.4
Total	35,553	40,566.8
Cash [Member]
Performance bonds	33,592.8	38,729
Guaranty Fund Contributions	1,919.2	1,719.9
Cross-margin arrangements	37.8	102.2
Performance collateral for delivery	3.2	15.7
Total	35,553	40,566.8
Non-Cash Deposits and IEF Funds [Member]
Performance bonds	91,954.4	93,972.7
Guaranty Fund Contributions	5,290	5,699
Cross-margin arrangements	163.7	91.2
Performance collateral for delivery	0	2.1
Total	$ 97,408.1	$ 99,765

Performance Bonds and Guarant56

Performance Bonds and Guaranty Fund Contributions (Performance Bond Deposits and Security Deposits) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Performance Bonds and Guaranty Fund Contributions [Abstract]
Performance bonds	$ 2,617.6	$ 2,441.9
Guaranty Fund Letters of Credit	25	25
Cross Margin Letters of Credit	0	5.5
Performance collateral for delivery	1,208	950.4
Letters of Credit	$ 3,850.6	$ 3,422.8

Property (Details)

Property (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, gross	$ 1,280.3	$ 1,249.9
Less accumulated depreciation and amortization	(788.6)	(741)
Property, net	491.7	508.9
Land and land improvements
Property, Plant and Equipment [Line Items]
Property, gross	17.7	17.7
Building and building improvements
Property, Plant and Equipment [Line Items]
Property, gross	280.8	273.5
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, gross	248.5	219.1
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Property, gross	333.3	360.1
Software and software development costs
Property, Plant and Equipment [Line Items]
Property, gross	$ 400	$ 379.5
Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum	2 years
Minimum [Member] | Land and land improvements
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum	10 years
Minimum [Member] | Building and building improvements
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum	3 years
Minimum [Member] | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum	3 years
Minimum [Member] | Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum	2 years
Minimum [Member] | Software and software development costs
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum	2 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum	39 years
Maximum [Member] | Land and land improvements
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum	20 years
Maximum [Member] | Building and building improvements
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum	39 years
Maximum [Member] | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum	24 years
Maximum [Member] | Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum	7 years
Maximum [Member] | Software and software development costs
Property, Plant and Equipment [Line Items]
Estimated useful life, minimum	4 years

Intangible Assets and Goodwil58

Intangible Assets and Goodwill (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Amortization of purchased intangibles	$ 99.4	$ 100.6	$ 103
Intangible assets-other, net	$ 2,537.9	$ 2,637.4

Intangible Assets and Goodwil59

Intangible Assets and Goodwill (Components of Intangible Assets) (Details) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Indefinite-lived Intangible Assets		$ 2,537.9	$ 2,637.4
Other Indefinite-lived Intangible Assets	[1]	17,175.3	17,175.3
Trade Names [Member]
Indefinite-lived Intangible Assets		450	450
Clearing Firm, Market Data, and Other Customer Relationships [Member]
Cost		2,838.8	2,838.8
Accumulated amortization		(754.5)	(658.8)
Net book value		2,084.3	2,180
Technology-Related Intellectual Property [Member]
Cost		29.4	29.4
Accumulated amortization		(27.2)	(23.5)
Net book value		2.2	5.9
Other - Finite [Member]
Cost		2.4	2.4
Accumulated amortization		(1)	(0.9)
Net book value		1.4	1.5
Finite-Lived Intangible Assets [Member]
Cost		2,870.6	2,870.6
Accumulated amortization		(782.7)	(683.2)
Net book value		$ 2,087.9	$ 2,187.4
[1]	(1)Trading products represent futures and options products acquired in our business combinations with CBOT Holdings, Inc., NYMEX Holdings, Inc. and KCBT. Clearing and transaction fees are generated through the trading of these products. These trading products, most of which have traded for decades, require authorization from the CFTC. Product authorizations from the CFTC have no term limits.

Intangible Assets and Goodwil60

Intangible Assets and Goodwill Intangible Assets and Goodwill (Useful Lives of Intangible Assets) (Details)	12 Months Ended
	Dec. 31, 2015
Minimum [Member] | Clearing Firm, Market Data, and Other Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life, minimum	5 years
Minimum [Member] | Technology-Related Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life, minimum	4 years
Minimum [Member] | Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life, minimum	3 years
Maximum [Member] | Clearing Firm, Market Data, and Other Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life, minimum	30 years
Maximum [Member] | Technology-Related Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life, minimum	5 years
Maximum [Member] | Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life, minimum	24 years 6 months

Intangible Assets and Goodwil61

Intangible Assets and Goodwill (Future Estimated Amortization Expense) (Details) $ in Millions	Dec. 31, 2015USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,015	$ 96.1
2,016	95.5
2,017	94.7
2,018	94.7
2,019	94.7
Thereafter	$ 1,612.2

Intangible Assets and Goodwil62

Intangible Assets and Goodwill (Goodwill Activity) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Total Goodwill, beginning balance	$ 7,569	$ 7,569
Business Combinations	0	0
Goodwill, Written off Related to Sale of Business Unit	0	0
Other Activity	0	0
Total Goodwill, ending balance	7,569	7,569
CBOT holdings [Member]
Total Goodwill, beginning balance	5,035.7	5,035.7
Business Combinations	0	0
Goodwill, Transfers	(30.7)
Goodwill, Written off Related to Sale of Business Unit		0
Other Activity	0	0
Total Goodwill, ending balance	5,066.4	5,035.7
NYMEX holdings [Member]
Total Goodwill, beginning balance	2,462.2	2,462.2
Business Combinations	0	0
Goodwill, Written off Related to Sale of Business Unit	0	0
Other Activity	0	0
Total Goodwill, ending balance	2,462.2	2,462.2
Other Affiliates [Member]
Total Goodwill, beginning balance	71.1	71.1
Business Combinations	0	0
Goodwill, Transfers	(30.7)
Goodwill, Written off Related to Sale of Business Unit		0
Other Activity	0	0
Total Goodwill, ending balance	$ 40.4	$ 71.1

Long-Term Investments (Details)

Long-Term Investments (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
BM&F [Member]
Equity Method Investment, Ownership Percentage	4.00%
Fair value of investment	$ 199.1	$ 410.8
Cost-basis value of investment	$ 258.4	405.7
Bolsa Mexicana De Valores, S A B De C V [Member]
Equity Method Investment, Ownership Percentage	2.00%
Fair value of investment	$ 15.5	21.2
Cost-basis value of investment	$ 17.3	$ 17.3
Bursa Malaysia Derivatives Berhad [Member]
Equity Method Investment, Ownership Percentage	25.00%
Fair value of investment	$ 28
DME Holdings [Member]
Equity Method Investment, Ownership Percentage	50.00%
Fair value of investment	$ 17.5
S&P/DJI [Member]
Equity Method Investment, Ownership Percentage	27.00%
Fair value of investment	$ 938.7

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Gains (Losses) on Extinguishment of Debt	$ (61.8)	$ 0	$ 0
Six Hundred Twelve Point Five Million Fixed Rate Notes Due March Two Thousand Eighteen, Interest Equal To Four Point Four Zero Percent [Member]
Debt instrument, face amount	612.5
call premium debt	60.5
Gains (Losses) on Extinguishment of Debt	$ 61.8

Debt (Schedule of Short-Term an

Debt (Schedule of Short-Term and Long-Term Debt) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Long-term Debt
Long-term debt		$ 2,241.4	$ 2,107.9
Six Hundred Twelve Point Five Million Fixed Rate Notes Due March Two Thousand Eighteen, Interest Equal To Four Point Four Zero Percent [Member]
Long-term Debt
Long-term debt		$ 0	611
Forward starting interest rate swap agreement fixed rate		4.46%
Debt instrument, face amount		$ 612.5
Debt Instrument, maturity date		Mar. 1, 2018
Debt Instrument, Interest Rate, Stated Percentage		4.40%
Seven Hundred Fifty Million Fixed Rate Notes Due March Two Thousand Twenty Two, Interest Equal To Four Point Three Zero Percent [Member]
Long-term Debt
Long-term debt	[1]	$ 748.4	748.2
Forward starting interest rate swap agreement fixed rate		3.32%
Debt instrument, face amount		$ 750
Debt Instrument, maturity date		Sep. 1, 2022
Debt Instrument, Interest Rate, Stated Percentage		3.00%
$750.0 million fixed rates notes due September 2043, stated rate of 5.30%
Long-term Debt
Long-term debt	[1]	$ 744.2	0
Forward starting interest rate swap agreement fixed rate		3.11%
Debt instrument, face amount		$ 750
Debt Instrument, maturity date		Mar. 1, 2025
Debt Instrument, Interest Rate, Stated Percentage		3.00%
$750.0 million fixed rate notes due March 2025, stated rate of 3.00%
Long-term Debt
Long-term debt	[1]	$ 748.8	$ 748.7
Forward starting interest rate swap agreement fixed rate		4.73%
Debt instrument, face amount		$ 750
Debt Instrument, maturity date		Sep. 1, 2043
Debt Instrument, Interest Rate, Stated Percentage		5.30%
[1]	In August 2012, the company entered into a forward-starting interest rate swap agreement that modified the interest obligation associated with these notes so that the interest payable on the notes effectively became fixed at a rate of 3.32%.

Debt (Long-Term Debt Maturities

Debt (Long-Term Debt Maturities at Par Value) (Details) $ in Millions	Dec. 31, 2015USD ($)
Debt Disclosure [Abstract]
2,016	$ 0
2,017	0
2,018	0
2,019	0
2,020	0
Thereafter	$ 2,250

Derivative Instruments (Narrati

Derivative Instruments (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Expected Derivative Amortization	$ 1.2
Derivative, Notional Amount		$ 500

Derivative Instruments (Effect

Derivative Instruments (Effect of Derivative Instruments on the Statements of Income and Shareholders' Equity) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	$ (4.7)	$ (2.3)	$ 128.8
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax	(1.2)	(1.5)	1.6
Derivative, Net Hedge Ineffectiveness Gain (Loss)	$ (1.8)	$ 0	$ 0

Derivative Instruments Fair Val

Derivative Instruments Fair Value of Derivatives by Balance Sheet Location (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Interest Rate Cash Flow Hedge Derivative at Fair Value, Net	$ 0	$ 2.3

Income Taxes (Income Tax Provis

Income Taxes (Income Tax Provision) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Income before income taxes: Domestic									$ 1,927.3	$ 1,783.7	$ 1,599.2
Income before income taxes: Foreign									29.5	(12.3)	1.8
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	$ 468.5	$ 516.4	$ 448.1	$ 523.8	$ 473.8	$ 429.1	$ 422.1	$ 446.4	1,956.8	1,771.4	1,601
Current income tax provision: Federal									554.5	526.4	491.9
Current income tax provision: State									81	36.5	128.8
Current income tax provision: Foreign									11	2.7	8.2
Current income tax provision: Total									646.5	565.6	628.9
Deferred income tax provision: Federal									75.6	47.1	(157.6)
Deferred income tax provision: State									(12)	32.4	153.4
Deferred income tax provision: Foreign									(0.3)	(0.6)	(1.8)
Deferred income tax provision: Total									63.3	78.9	(6)
Total Income Tax Provision									$ 709.8	$ 644.5	$ 622.9

Income Taxes (Federal Income Ta

Income Taxes (Federal Income Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Statutory U.S. federal tax rate	35.00%	35.00%	35.00%
State taxes, net of federal benefit	3.00%	1.60%	4.80%
Effective Income Tax Rate Reconciliation, Deductions, Qualified Production Activities	(1.30%)	(1.40%)	(7.70%)
Increase (decrease) in domestic valuation allowance	0.10%	0.10%	0.60%
Impact of revised state apportionment estimates	(0.70%)	1.10%	6.60%
Other, net	0.20%	0.00%	(0.40%)
Effective Tax Rate	36.30%	36.40%	38.90%

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets (Liabilities) ) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Deferred Tax Assets, Gross, Current	$ 27.9	$ 24.4
Subtotal	213.4	258.3
Valuation allowance	(122.3)	(99.2)
Total non-current deferred tax assets	91.1	159.1
Deferred Tax Liabilities, Gross, Current	7,449.4	7,461.8
Deferred Tax Liabilities, Net, Noncurrent	7,358.3	7,302.7
current [Member]
Unrealized loss on securities	1.1	3
Stock-based compensation	19.1	19.2
Accrued expenses and other	7.7	2.2
Noncurrent [Member]
Unrealized loss on securities	14.9	16.5
Domestic unrealized loss on investment in BM&FBOVESPA	85.6	101.7
Deferred Tax Assets, Unrealized Currency Losses	15.6	19.7
Deferred tax asset Domestic Losses	14.1	7.3
Stock-based compensation	24.1	30.7
Deferred compensation	31.8	38.1
Deferred Tax Assets, Property, Plant and Equipment	27.3	44.3
Purchase intangible assets	(7,434.1)	(7,448.2)
Deferred Tax Liabilities, Other	$ 15.3	$ 13.6

Income Taxes (Summary Of Unreco

Income Taxes (Summary Of Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Gross unrecognized tax benefits	$ 206.9	$ 187.6	$ 231.6	$ 37.7
Unrecognized tax benefits, net of tax impacts in other jurisdictions	179.6	160.8	183.3
Interest and penalties related to uncertain tax positions	19.5	11	42.5
Interest and penalties recognized in the consolidated statements of income	$ 8.6	$ (12.5)	$ 22.4

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Balance as of January 1	$ 187.6	$ 231.6	$ 37.7
Additions based on tax positions related to the current year	20.4	30.5	26.1
Additions for tax positions of prior years	2.7	24.9	168.4
Reductions for tax positions of prior years	(3.8)	(51.8)	(0.4)
Reductions resulting from the lapse of statutes of limitations	0	0	(0.2)
Settlements with taxing authorities	0	(47.6)	0
Balance as of December 31	$ 206.9	$ 187.6	$ 231.6

Income Taxes Income Taxes (Narr

Income Taxes Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards	$ 124.5	$ 118.9
Unrealized capital tax loss	270.9	317.7
Deferred Tax Assets, Valuation Allowance, Noncurrent	122.3	99.2
Long-term deferred tax asset	$ 213.4	$ 258.3

Employee Benefit Plans (Narrati

Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Amortization of actuarial loss from accumulated other comprehensive income (loss) into net periodic benefit costs	$ 3.5
Defined Contribution Plan, Cost Recognized	11.7	$ 11.2	$ 9.9
Trading securities fair value	55.9	55.1
Other Postretirement Benefit Plan [Member]
Total contribution	2	0.8	$ 0.8
Total obligation	19.9	21.2
Fair value of assets	$ 22	20
Pension Plans [Member]
Age for participation eligibility in benefit plan	21
Years of service for vesting eligibility	3 years
Accumulated benefit obligation	$ 190.8	195.6
Excess of pension plan assets over the projected benefit obligation	$ 0.2	$ 1.4
Defined Benefit Plan Funding Goal Percentage	100.00%
Estimated liabilities exceeding the fair value of the plan assets	$ 11.7
Estimated contribution to meet projected excess of pension plan liabilities of pension plan assets	$ 11.7
Percentage of employees base salary matched by employer, maximum	3.00%
Pension Plans [Member]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Cash Balance Interest Crediting Rate	4.00%	4.00%	4.00%

Employee Benefit Plans (Summary

Employee Benefit Plans (Summary of the change in projected benefit obligation) (Details) - Pension Plans [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Balance at January 1	$ 223.7	$ 175.7
Service cost	18.4	17.1	$ 18
Interest cost	9.8	9.6	7.9
Actuarial (gain) loss	(11.6)	30.1
Benefits paid	(23)	(8.8)	(8.4)
Balance at December 31	$ 217.3	$ 223.7	$ 175.7

Employee Benefit Plans (Change

Employee Benefit Plans (Change in Plan Assets) (Details) - Pension Plans [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance at January 1	$ 225.1	$ 193.6	$ 183.9
Actual return on plan assets	(7.2)	14.3	18.1
Employer contributions	22.6	26	0
Benefits paid	(23)	(8.8)	(8.4)
Balance at December 31	$ 217.5	$ 225.1	$ 193.6

Employee Benefit Plans (Fair Va

Employee Benefit Plans (Fair Value of Plan Assets) (Details) - Pension Plans [Member] - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan, Fair Value of Plan Assets	$ 217.5	$ 225.1	$ 193.6	$ 183.9
Fair Value, Inputs, level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets	217.5	225.1
Fair Value, Inputs, level 2 [Member] | Money Market Funds [Member]
Defined Benefit Plan, Fair Value of Plan Assets	26.5	27.2
Fair Value, Inputs, level 2 [Member] | Fixed Income Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets	61.6	67.2
Fair Value, Inputs, level 2 [Member] | US Equity [Member]
Defined Benefit Plan, Fair Value of Plan Assets	59.9	63.4
Fair Value, Inputs, level 2 [Member] | Foreign Equity [Member]
Defined Benefit Plan, Fair Value of Plan Assets	60	57.6
Fair Value, Inputs, level 2 [Member] | Commodity [Member]
Defined Benefit Plan, Fair Value of Plan Assets	$ 9.5	$ 9.7

Employee Benefit Plans (Compone

Employee Benefit Plans (Components of Net Pension Expense) (Details) - Pension Plans [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components of Net Pension Expense:
Service cost	$ 18.4	$ 17.1	$ 18
Interest cost	9.8	9.6	7.9
Expected return on plan assets	(16.3)	(14)	(13.3)
Recognized net actuarial loss	2.7	0.6	3.1
Net Pension Expense	$ 14.6	$ 13.3	$ 15.7
Assumptions Used to Determine End-of-Year Benefit Obligation:
Discount rate	4.60%	4.20%	5.10%
Rate of compensation increase	5.00%	5.00%	5.00%
Cash balance interest crediting rate	4.00%	4.00%	4.00%
Assumptions Used to Determine Net Pension Expense:
Discount rate	4.20%	5.10%	4.10%
Rate of compensation increase	5.00%	5.00%	5.00%
Expected return on plan assets	7.50%	7.50%	7.50%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Cash Balance Interest Crediting Rate	4.00%	4.00%	4.00%

Employee Benefit Plans (Asset A

Employee Benefit Plans (Asset Allocation for the Plan) (Details) - Pension Plans [Member]	Dec. 31, 2015	Dec. 31, 2014
Fixed Income [Member]
Actual allocation of plan assets, Fixed income	28.30%	29.80%
Foreign Equity [Member]
Actual allocation of plan assets, Fixed income	27.60%	25.60%
US Equity [Member]
Actual allocation of plan assets, Fixed income	27.50%	28.20%
Money Market Funds [Member]
Actual allocation of plan assets, Fixed income	12.20%	12.10%
Commodity [Member]
Actual allocation of plan assets, Fixed income	4.40%	4.30%

Employee Benefit Plans (Target

Employee Benefit Plans (Target Allocation Percentages) (Details) - Pension Plans [Member]	12 Months Ended
	Dec. 31, 2015
US Equity [Member]
Minimum	23.50%
Maximum	35.00%
Foreign Equity [Member]
Minimum	23.50%
Maximum	35.00%
Fixed Income [Member]
Minimum	33.00%
Maximum	45.00%
Commodity [Member]
Minimum	2.00%
Maximum	8.00%

Employee Benefit Plans (Accumul

Employee Benefit Plans (Accumulated Other Comprehensive Income (Loss), of the Prior Service Costs and Actuarial Losses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Actuarial Losses [Roll Forward]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax	$ (11.2)	$ (30)	$ 28.4
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, before Tax	2.7	0.3	$ 3.2
Pension Plans [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Prior Service Cost Beginning Balance	0.1
Defined Benefit Plan, Amortization of Net Prior Service Cost (Credit)	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0
Prior Service Cost Ending Balance	0.1	0.1
Actuarial Losses [Roll Forward]
Actuarial Loss Beginning Balance	(51.6)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax	11.9
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, before Tax	(2.7)
Actuarial Loss Ending Balance	$ (60.8)	$ (51.6)

Employee Benefit Plans (Anticip

Employee Benefit Plans (Anticipated Benefit Payments from the Plan in Future Years) (Details) - Pension Plans [Member] $ in Millions	Dec. 31, 2015USD ($)
2,016	$ 14.1
2,017	14.7
2,018	15.6
2,019	17.1
2,020	18
2021-2025	$ 113.8

Commitments (Narrative) (Detail

Commitments (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)yearsRenewalOptions	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Operating leases, rent expense | $	$ 54.8	$ 51	$ 28.6
NYMEX [Member]
Operating leases number of renewal options | years	2
Lessee Leasing Arrangements, Operating Leases, Renewal Term	5 years
Chicago CBOT Building [Member] [Member]
Operating leases number of renewal options	4
Lessee Leasing Arrangements, Operating Leases, Renewal Term	5 years
Chicago [Member]
Operating leases number of renewal options	2
Additional Office Space Chicago [Member]
Operating leases number of renewal options	2
Lessee Leasing Arrangements, Operating Leases, Renewal Term	5 years
First Lease Renewal Option [Member]
Lessee Leasing Arrangements, Operating Leases, Renewal Term	7 years
Second Lease Renewal Option [Member]
Lessee Leasing Arrangements, Operating Leases, Renewal Term	10 years

Commitments (Non-Cancelable Ope

Commitments (Non-Cancelable Operating Leases and Contractual Obligations) (Details) $ in Millions	Dec. 31, 2015USD ($)
Operating Leases, Future Minimum Payments Due [Abstract]
2,016	$ 50.2
2,017	44.3
2,018	45.1
2,019	44.8
2,020	42.1
Thereafter	182.8
Total	409.3
Unrecorded Unconditional Purchase Obligation [Abstract]
2,016	10.7
2,017	10.2
2,018	9.7
2,019	1.4
2,020	0.7
Thereafter	1.4
Total	$ 34.1

Contingencies (Details)

Contingencies (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Accrued liability related to all outstanding legal matters	$ 3.5	$ 4.3

Guarantees (Details)

Guarantees (Details)	12 Months Ended
	Dec. 31, 2015USD ($)
Guarantor Obligations [Line Items]
PaymentPerParticipant	$ 25,000
Contingent liability to SGX, amount of irrevocable letters of credit	610
PaymentPerCooperative	$ 100,000
FutureLosses	100,000,000
Family Farmer and Ranchers Protection Fund [Member]
Guarantor Obligations [Line Items]
Payments under Guarantee	2,000,000
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 98,000,000

Redeemable Non-Controlling In89

Redeemable Non-Controlling Interest (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2013	Dec. 31, 2015	Apr. 30, 2013	Mar. 18, 2010
Noncontrolling Interest [Line Items]
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests	$ 80
Adjustments to Additional Paid in Capital, Deferred Tax Liabilities	165.6
Gain on Purchase of NonControlling Interest	$ 2.3
Purchase of non-controlling interest		$ (82.3)
Dow Jones [Member]
Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners					10.00%
CME Group net of non-controlling interest [Member]
Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners			24.40%
S&P/Dow Jones Indices LLC [Member]
Noncontrolling Interest [Line Items]
Equity Method Investment, Ownership Percentage				27.00%

Redeemable Non-Controlling In90

Redeemable Non-Controlling Interest Rollforward Table (Details) $ in Millions	12 Months Ended
	Dec. 31, 2013USD ($)
Redeemable Non-Controlling Interest
Redeemable non-controlling interest, Balance January 1	$ 80.8
Total comprehensive income attributable to redeemable non-controlling interest	1.5
Purchase of non-controlling interest	(82.3)
Redeemable non-controlling interest, Balance December 31	$ 0

Capital Stock (Narrative) (Deta

Capital Stock (Narrative) (Details)	12 Months Ended
	Dec. 31, 2015directors$ / sharesshares	Dec. 31, 2014$ / shares
Number of directors	24
Class A Common Stock (Shares) [Member]
Common Stock, Par or Stated Value Per Share | $ / shares	$ 0.01	$ 0.01
Class B Common Stock (Shares)
Common Stock, Par or Stated Value Per Share | $ / shares	$ 0.01	$ 0.01
Common stock, voting rights	1
Class B Common Stock, Class B1 [Member]
Common stock, voting rights	6
Number of directors | directors	3
Class B Common Stock, Class B2 [Member]
Common stock, voting rights	2
Number of directors | directors	2
Class B Common Stock, Class B3 [Member]
Common stock, voting rights	1
Number of directors | directors	1
Class B Common Stock, Class B4 [Member]
Common stock, voting rights	1/6
Class B common stock, Class B1, B2, B3 [Member]
Number of directors | directors	6
CME Group Omnibus Stock Plan [Member]
Shares granted, outstanding and exercised	23,300,000
Number of shares reserved for awards under the plan	40,200,000
CBOT Holdings Long-Term Equity Plan [Member]
Number of shares reserved for awards under the plan	2,300,000
NYMEX Holdings Omnibus Long-Term Incentive Plan [Member]
Number of shares reserved for awards under the plan	5,000,000
Shares authorized for future awards, frozen awards	3,600,000
Director Stock Plan; Class A Shares [Member]
Number of shares reserved for awards under the plan	625,000
Class A shares awarded under Director Stock Plan	320,000
Employee Stock Purchase Plan; Class A Shares [Member]
Number of shares reserved for awards under the plan	500,000
Market value of the shares an Employee Stock Purchase Plan	90.00%
Class A shares Purchased under Employee Stock Purchase Plan	220,000

Capital Stock (Capital stock) (

Capital Stock (Capital stock) (Details) - shares	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Class A Common Stock
Common Stock, Shares Authorized	1,000,000,000	1,000,000,000
Common Stock, Shares, Outstanding	336,938,000	335,452,000	333,852,000	331,832,000
Class B Common Stock, Class B1 [Member]
Common Stock, Shares, Outstanding	600	600
Class B Common Stock, Class B2 [Member]
Common Stock, Shares, Outstanding	800	800
Class B Common Stock, Class B3 [Member]
Common Stock, Shares, Outstanding	1,300	1,300
Class B Common Stock, Class B4 [Member]
Common Stock, Shares, Outstanding	400	400

Stock-Based Payments (Narrative

Stock-Based Payments (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Vesting percentage after one year	25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$ 94,900,000
Employee service share-based compensation, unrecognized compensation costs on nonvested awards, Weighted Average Period of Recognition, years	2 years 2 months
Share-based compensation arrangement by share-based payment award, options, exercises in period, total intrinsic value	$ 29,500,000	$ 29,500,000	$ 35,300,000
Granted performance shares	704,162
Restricted Class A common stock, fair value	$ 43,300,000	40,500,000	31,900,000
Total expense for stock payments	$ 61,000,000	$ 55,000,000	$ 54,400,000
Share-based compensation arrangement by share-based payment award, discount from market price	90.00%
Class A common stock issued to participating employees	19,756	23,678	18,632
Director Stock Plan; Class A Shares [Member]
Total expense for stock payments	$ 2,500,000	$ 2,100,000	$ 2,100,000
Annual award of class A common stock value	100,000
Annual stipend allowance in shares of stock	$ 60,000
Annual stipend allowance in shares of stock (in shares)	25,853	33,735	27,168
Employee Stock Purchase Plan; Class A Shares [Member]
Total expense for stock payments	$ 200,000	$ 200,000	$ 100,000
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	2 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Performance Shares [Member]
Granted performance shares	122,317
Restricted Class A common stock, fair value	$ 12,300,000
Restricted Stock Units (RSUs) [Member]
Stock options, granted, shares	7,392
Class A Common Stock (Shares) [Member]
Stock options, granted, shares	574,453
Restricted Class A common stock, fair value	$ 55,500,000
CME Group Omnibus Stock Plan [Member]
Share-based compensation arrangement by share-based payment award, number of shares reserved	40,200,000
Share-based compensation arrangement by share-based payment award, number of shares authorized	23,300,000

Stock-Based Payments (Compensat

Stock-Based Payments (Compensation Expense And Income Tax Benefit Recognized) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 61	$ 55	$ 54.4
Income tax benefit recognized	$ 32.4	$ 19.5	$ 20

Stock-Based Payments (Stock Opt

Stock-Based Payments (Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding in Shares [Roll Forward]
Number of shares outstanding at December 31 (shares)	3,011,267
Number of shares exercised	(984,581)
Number of shares cancelled	(212,635)
Number of shares outstanding at December 31 (shares)	1,814,051	3,011,267
Number of shares exercisable at December 31 (shares)	1,812,746
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Weighted average exercise price outstanding, beginning	$ 73	$ 72
Weighted average exercise price exercised	65
Weighted average exercise price cancelled	101
Weighted average exercise price outstanding, ending	72
Weighted average exercise price exercisable	$ 73
Weighted average remaining contractual life outstanding	3 years 3 months	3 years 8 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Remaining Contractual Term	3 years 3 months
Aggregate intrinsic value outstanding, beginning	$ 60.1
Aggregate intrinsic value outstanding, ending	38.7	$ 60.1
Aggregate intrinsic value exercisable	$ 38.6

Stock-Based Payments (Restricte

Stock-Based Payments (Restricted Stock Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of shares outstanding at December 31 (shares)	2,098,308
Number of shares granted	704,162
Number of shares vested	(456,153)
Number of shares cancelled	(424,019)
Number of shares outstanding at December 31 (shares)	1,922,298
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Weighted average grant date fair value outstanding	$ 83	$ 72
Weighted average grant date fair value granted	96
Weighted average grant date fair value vested	67
Weighted average grant date fair value cancelled	$ 70

Accumulated Other Comprehensi97

Accumulated Other Comprehensive Income (Loss) (Schedule of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income [Roll Forward]
Stockholders' Equity Attributable to Parent, beginning	$ 20,923.5
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax	(78)	$ (116.6)	$ (221)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	(10.6)	(5.2)	(0.8)
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, before Tax	2.7	0.3	3.2
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	(4.7)	(2.3)	128.8
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, before Tax	8.5	0	(0.7)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax	(1.2)	(1.5)	1.6
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	(2.6)	(5.2)	63.9
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax	3.2	11.2	(12)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	4	2.1	0.3
Other Comprehensive Income (Loss), Net of Tax	(87)	(145.8)	(57.3)
Stockholders' Equity Attributable to Parent, ending	20,551.8	20,923.5
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Stockholders' Equity Attributable to Parent, beginning	(31.3)	(12.8)	(32.4)
Other comprehensive income before reclassifications and income tax benefit (expense)	(11.2)	(30)	28.4
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, before Tax	2.7	0.3	3.2
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax	3.2	11.2	(12)
Other Comprehensive Income (Loss), Net of Tax	(5.3)	(18.5)	19.6
Stockholders' Equity Attributable to Parent, ending	(36.6)	(31.3)	(12.8)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Stockholders' Equity Attributable to Parent, beginning	(22.9)	98.9	256.7
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax	(78)	(116.6)	(221)
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, before Tax	8.5	0	(0.7)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	(2.6)	(5.2)	63.9
Other Comprehensive Income (Loss), Net of Tax	(72.1)	(121.8)	(157.8)
Stockholders' Equity Attributable to Parent, ending	(95)	(22.9)	98.9
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Stockholders' Equity Attributable to Parent, beginning	62.6	65	(16.4)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	(4.7)	(2.3)	128.8
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax	0.6	(1.5)	1.6
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	1.1	1.4	(49)
Other Comprehensive Income (Loss), Net of Tax	(3)	(2.4)	81.4
Stockholders' Equity Attributable to Parent, ending	59.6	62.6	65
Foreign Currency Gain (Loss) [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Stockholders' Equity Attributable to Parent, beginning	(2.2)	0.9	1.4
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	(10.6)	(5.2)	(0.8)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment Realized upon Sale or Liquidation, before Tax	0	0	0
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	4	2.1	0.3
Other Comprehensive Income (Loss), Net of Tax	(6.6)	(3.1)	(0.5)
Stockholders' Equity Attributable to Parent, ending	(8.8)	(2.2)	0.9
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Stockholders' Equity Attributable to Parent, beginning	6.2	152	209.3
Comprehensive Income Before Reclassification Adjustments	(104.5)	(154.1)	(64.6)
Comprehensive Income Reclassification Adjustments	11.8	(1.2)	4.1
Other Comprehensive Income (Loss), Net of Tax	5.7	9.5	3.2
Other Comprehensive Income (Loss), Net of Tax	(87)	(145.8)	(57.3)
Stockholders' Equity Attributable to Parent, ending	$ (80.8)	$ 6.2	$ 152

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details)	12 Months Ended
	Dec. 31, 2015
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Fair Value Inputs, Discount Rate	20.00%
fair value inputs probability of payout	100.00%

Fair Value Measurements (Financ

Fair Value Measurements (Financial Instruments Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	$ 16.6	$ 19.6
Trading Securities at Fair Value	55.9	55.1
Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0.3
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable Securities at Fair Value	72.5	74.7
Investment Owned, at Fair Value	214.5	432.1
Total Assets at Fair Value	11,260.9	17,206.5
Derivative Liability		2.3
Business Combination, Contingent Consideration Liability	0.3	17.7
Total liabilities at fair value	0.3	20
Fair Value, Measurements, Recurring [Member] | US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	16.2	19.1
Fair Value, Measurements, Recurring [Member] | Mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities at Fair Value	55.9	55.1
Fair Value, Measurements, Recurring [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0.1	0.1
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0.3	0.4
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable Securities at Fair Value	72.2	74.3
Investment Owned, at Fair Value	214.5	432.1
Total Assets at Fair Value	11,260.6	17,206.1
Derivative Liability		0
Business Combination, Contingent Consideration Liability	0	0
Total liabilities at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 1 [Member] | US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	16.2	19.1
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 1 [Member] | Mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities at Fair Value	55.9	55.1
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 1 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0.1	0.1
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 1 [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable Securities at Fair Value	0.3	0.4
Investment Owned, at Fair Value	0	0
Total Assets at Fair Value	0.3	0.4
Derivative Liability		2.3
Business Combination, Contingent Consideration Liability	0	0
Total liabilities at fair value	0	2.3
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 2 [Member] | US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 2 [Member] | Mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities at Fair Value	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 2 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 2 [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0.3	0.4
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable Securities at Fair Value	0	0
Investment Owned, at Fair Value	0	0
Total Assets at Fair Value	0	0
Derivative Liability		0
Business Combination, Contingent Consideration Liability	0.3	17.7	$ 15.7
Total liabilities at fair value	0.3	17.7
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 3 [Member] | US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 3 [Member] | Mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities at Fair Value	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 3 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 3 [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
U.S. Treasury Performance Bond [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	11,000	16,700
U.S. Treasury Performance Bond [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	10,973.9	16,699.7
U.S. Treasury Performance Bond [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	10,973.9	16,699.7
U.S. Treasury Performance Bond [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
U.S. Treasury Performance Bond [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	$ 0	$ 0

Fair Value Measurements (Reconc

Fair Value Measurements (Reconciliation Using Significant Unobservable Inputs) (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Business Combination, Contingent Consideration Liability, Beginning	$ 17.7
Business Combination, Contingent Consideration Liability, Ending	0.3	$ 17.7
Fair Value, Inputs, level 3 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Business Combination, Contingent Consideration Liability, Beginning	17.7	15.7
Included in operating expense	1.3	7.1
Contingent Consideration Settlement	(18.7)	(5.1)
Business Combination, Contingent Consideration Liability, Ending	$ 0.3	$ 17.7

Fair Value Measurements (Debt I

Fair Value Measurements (Debt Instruments) (Details) $ in Millions	Dec. 31, 2015USD ($)
$750.0 million fixed rate notes due September 2022, stated rate of 3.00%
Debt Instrument, Fair Value Disclosure	$ 758.4
$750.0 million fixed rate notes due March 2025, stated rate of 3.00%
Debt Instrument, Fair Value Disclosure	856.3
$750.0 million fixed rates notes due September 2043, stated rate of 5.30%
Debt Instrument, Fair Value Disclosure	$ 743.3

Earnings Per Share (Basic and D

Earnings Per Share (Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net income attributable to CME Group	$ 291.7	$ 359.9	$ 265	$ 330.4	$ 306.5	$ 290	$ 263.8	$ 266.8	$ 1,247	$ 1,127.1	$ 976.8
Basic									336,224	334,409	332,678
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements									1,670	1,654	1,720
Diluted									337,894	336,063	334,398
Earnings per common share, basic	$ 0.87	$ 1.07	$ 0.79	$ 0.98	$ 0.91	$ 0.87	$ 0.79	$ 0.80	$ 3.71	$ 3.37	$ 2.94
Earnings per common share, diluted	$ 0.86	$ 1.06	$ 0.78	$ 0.98	$ 0.91	$ 0.86	$ 0.79	$ 0.79	$ 3.69	$ 3.35	$ 2.92
Outstanding anti-dilutive options									535	1,454	1,631
Stock Options [Member]
Outstanding anti-dilutive options									420	1,330	1,566
Restricted Stock [Member]
Outstanding anti-dilutive options									115	124	65

Quarterly Information (Unaud103

Quarterly Information (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Data [Abstract]
Total Revenues	$ 813.8	$ 850.3	$ 820	$ 842.7	$ 841.1	$ 762.4	$ 731.6	$ 777.4	$ 3,326.8	$ 3,112.5	$ 2,936.3
Operating Income	469.9	516.4	495.1	507.3	471.5	430.4	412	454.5	1,988.7	1,768.4	1,637
Non-operating income (expense)	(1.4)	0	(47)	16.5	2.3	(1.3)	10.1	(8.1)	(31.9)	3	(36)
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	468.5	516.4	448.1	523.8	473.8	429.1	422.1	446.4	1,956.8	1,771.4	1,601
Net income attributable to CME Group	$ 291.7	$ 359.9	$ 265	$ 330.4	$ 306.5	$ 290	$ 263.8	$ 266.8	$ 1,247	$ 1,127.1	$ 976.8
Earnings per Common Share Attributable to CME Group:
Basic	$ 0.87	$ 1.07	$ 0.79	$ 0.98	$ 0.91	$ 0.87	$ 0.79	$ 0.80	$ 3.71	$ 3.37	$ 2.94
Diluted	$ 0.86	$ 1.06	$ 0.78	$ 0.98	$ 0.91	$ 0.86	$ 0.79	$ 0.79	$ 3.69	$ 3.35	$ 2.92
Weighted Average Number of Common Shares:
Basic									336,224	334,409	332,678
Diluted									337,894	336,063	334,398

Schedule II_Valuation and Qu104

Schedule II—Valuation and Qualifying Accounts Schedule II—Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 1.2	$ 1.2	$ 0.8
Charged against goodwill	0	0	0
Charged (credited) to costs and expenses	1.1	0.1	0.8
Other	(0.4)	(0.1)	(0.4)
Balance at end of year	1.9	1.2	1.2
Allowance for deferred tax assets
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	99.2	47.5	24.8
Charged against goodwill	0	0	0
Charged (credited) to costs and expenses	(2.4)	0	4.6
Other	25.5	51.7	18.1
Balance at end of year	$ 122.3	$ 99.2	$ 47.5