Cboe Global Markets (CBOE) 10-K 20 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2014	Feb. 11, 2015	Jun. 30, 2014
Entity Information [Line Items]
Entity Registrant Name	CBOE Holdings, Inc.
Entity Central Index Key	1374310
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		84,003,241
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$4.20

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current Assets:
Cash and cash equivalents	$147,927	$221,341
Accounts receivable—net allowances of 2014 - $285 and 2013 - $266	58,386	49,888
Marketing fee receivable	10,697	8,869
Income taxes receivable	21,503	22,039
Other prepaid expenses	4,622	4,007
Other current assets	972	2,717
Total Current Assets	244,107	308,861
Investments in Affiliates	12,351	14,581
Land	4,914	4,914
Property and Equipment:
Construction in progress	0	23
Building	68,019	65,448
Furniture and equipment	286,723	271,437
Less accumulated depreciation and amortization	-287,886	-269,614
Total Property and Equipment—Net	66,856	67,294
Other Assets:
Software development work in progress	7,817	7,853
Data processing software and other assets (less accumulated amortization of 2014 - $163,486; 2013 - $147,322)	47,856	38,086
Total Other Assets—Net	55,673	45,939
Total	383,901	441,589
Current Liabilities:
Accounts payable and accrued expenses	58,566	52,958
Dividends Payable, Current	0	43,831
Marketing fee payable	11,236	9,442
Deferred revenue	1,988	1,100
Post-retirement medical benefits	101	127
Income tax payable	1,774	0
Total Current Liabilities	73,665	107,458
Long-term Liabilities:
Post-retirement medical benefits	1,612	2,110
Income tax liability	40,683	29,903
Other long-term liabilities	4,197	3,856
Deferred income taxes	13,677	13,745
Total Long-term Liabilities	60,169	49,614
Commitments and Contingencies
Total Liabilities	133,834	157,072
Stockholders’ Equity:
Preferred stock, $0.01 par value: 20,000,000 shares authorized, no shares issued and outstanding at December 31, 2014 or 2013	0	0
Additional paid-in-capital	110,112	90,985
Retained earnings	472,005	349,290
Treasury stock at cost – 8,454,714 shares at December 31, 2014 and 5,074,755 shares at December 31, 2013	-332,287	-155,627
Accumulated other comprehensive loss	-689	-1,050
Stockholders' Equity Attributable to Parent	250,067	284,517
Liabilities and Stockholders’ Equity	383,901	441,589
Unrestricted Common Stock [Member]
Stockholders’ Equity:
Unrestricted common stock, $0.01 par value: 325,000,000 shares authorized; 92,569,189 issued and 84,114,475 outstanding at December 31, 2014; 91,845,492 issued and 86,770,737 outstanding at December 31, 2013	$926	$919

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Current Assets:
Accounts receivable, allowances (in dollars)	$285	$266
Other Assets:
Data processing software and other assets, accumulated amortization (in dollars)	$163,486	$147,322
Shareholders' Equity:
Preferred stock, par value (in dollars, per share)	$0.01	$0.01
Preferred Stock, Shares Authorized	20,000,000	20,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Treasury stock at cost, shares	8,454,714	5,074,755
Unrestricted Common Stock
Shareholders' Equity:
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, shares authorized	325,000,000	325,000,000
Common stock, shares issued	92,569,189	91,845,492
Common stock, shares outstanding	84,114,475	86,770,737

Consolidated_Statement_of_Inco

Consolidated Statement of Income (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Revenues:
Transaction fees	$437,764	$397,218	$357,146
Access fees	59,332	61,022	64,070
Exchange services and other fees	38,042	37,250	31,368
Market data fees	30,447	24,911	24,360
Regulatory fees	37,083	36,631	20,995
Other revenue	14,557	15,018	14,399
Total Operating Revenues	617,225	572,050	512,338
Operating Expenses:
Employee costs	121,734	118,083	104,196
Depreciation and amortization	39,913	34,488	31,485
Data processing	19,189	17,898	19,603
Outside services	31,976	34,473	36,300
Royalty fees	66,110	56,576	46,135
Trading volume incentives	4,080	4,355	6,275
Travel and promotional expenses	9,046	9,806	10,006
Facilities costs	5,721	5,053	5,066
Other expenses	5,655	5,504	9,175
Total Operating Expenses	303,424	286,236	268,241
Operating Income	313,801	285,814	244,097
Other Income/(Expense):
Investment income	113	63	149
Net loss from investment in affiliates	-4,217	-2,221	-1,695
Total Other Expense	-4,104	-2,158	-1,546
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	309,697	283,656	242,551
Income tax provision	119,983	107,657	85,156
Net Income	189,714	175,999	157,395
Net Income allocated to participating securities	1,322	2,136	2,141
Net Income Allocated to Common Stockholders	$188,392	$173,863	$155,254
Net income per share allocated to common stockholders (Note 14)
Basic (in dollars per share)	$2.21	$1.99	$1.78
Diluted—net income per share to common stockholders	$2.21	$1.99	$1.78
Weighted average shares used in computing income per share:
Weighted Average Number of Shares Outstanding, Basic	85,406	87,331	87,460
Diluted	85,406	87,331	87,460

Consolidated_Statement_of_Comp

Consolidated Statement of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Income	$189,714	$175,999	$157,395
Post retirement benefit obligation	361	-157	6
Comprehensive Income	190,075	175,842	157,401
Comprehensive Income allocated to participating securities	1,322	2,136	2,141
Comprehensive Income allocated to common stockholders	$188,753	$173,706	$155,260

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Income (Loss) Attributable to Parent	$189,714,000	$175,999,000	$157,395,000
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	39,913,000	34,488,000	31,485,000
Other amortization	87,000	114,000	88,000
Provision for deferred income taxes	-290,000	-7,145,000	-495,000
Stock-based compensation	15,577,000	20,823,000	12,348,000
Equity in loss of affiliates	1,217,000	1,976,000	1,695,000
Impairment of investment in affiliates and other assets	3,000,000	245,000	0
Loss on disposition of property	662,000	3,000	1,000
Changes in assets and liabilities:
Accounts receivable	-8,498,000	-4,222,000	-8,088,000
Marketing fee receivable	-1,828,000	-3,653,000	-21,000
Income taxes receivable	536,000	-10,321,000	-4,961,000
Prepaid expenses	-615,000	139,000	6,000
Other current assets	1,745,000	-2,151,000	498,000
Accounts payable and accrued expenses	5,888,000	5,516,000	1,113,000
Marketing fee payable	1,794,000	3,634,000	43,000
Increase (Decrease) in Income Taxes	1,774,000	0	0
Deferred revenue and other liabilities	1,229,000	-75,000	773,000
Post-retirement benefit obligations	-28,000	-36,000	-17,000
Income tax liability	10,780,000	9,046,000	8,672,000
Net Cash Flows provided by Operating Activities	262,657,000	224,380,000	200,535,000
Cash Flows from Investing Activities:
Capital and other assets expenditures	-50,154,000	-28,673,000	-30,066,000
Other	3,000	8,000	0
Net Cash Flows used in Investing Activities	-52,138,000	-31,197,000	-32,977,000
Cash Flows from Financing Activities:
Payment of quarterly dividends	-66,999,000	-58,369,000	-47,828,000
Payment of special dividend	-43,831,000		-66,197,000
Excess tax benefits from stock-based compensation plan	3,557,000	2,356,000	0
Purchase of unrestricted stock from employees	-8,332,000	-6,136,000	-3,128,000
Purchase of unrestricted common stock under announced program	-168,328,000	-45,290,000	-49,744,000
Net Cash Flows used in Financing Activities	-283,933,000	-107,439,000	-166,897,000
Net Increase (Decrease) in Cash and Cash Equivalents	-73,414,000	85,744,000	661,000
Cash and Cash Equivalents at Beginning of Period	221,341,000	135,597,000	134,936,000
Cash and Cash Equivalents at End of Period	147,927,000	221,341,000	135,597,000
Supplemental Disclosure of Cash Flow Information
Cash paid for income taxes	103,976,000	113,741,000	82,633,000
Non-cash activities:
Change in post-retirement benefit obligation	-583,000	255,000	-25,000
Dividends Payable, Current	0	43,831,000	0
Unpaid liability to acquire equipment and software	2,769,000	3,048,000	755,000
Investment in Signal Trading [Member]
Cash Flows from Investing Activities:
Investment in Signal Trading Systems, LLC	-1,987,000	-1,920,000	-1,661,000
Investment in IPXI [Member]
Cash Flows from Investing Activities:
Investment in Signal Trading Systems, LLC	$0	($612,000)	($1,250,000)

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders’ Equity (USD $)	Total	Preferred Stock	Unrestricted Common Stock [Member]	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
In Thousands
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Beginning of Period at Dec. 31, 2011	$236,270	$0	$908	$55,469	$232,121	($51,329)	($899)
Cash dividends on common stock	-114,025				-114,025
Stock-based compensation	12,348			12,348
Issuance of vested restricted stock granted to employees	0		5	-5
Excess tax benefits from stock-based compensation plan	0
Purchase of unrestricted common stock	-52,872					-52,872
Net income	157,395				157,395
Post-retirement benefit obligation adjustments- net of tax	6						6
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest End of Period at Dec. 31, 2012	239,122	0	913	67,812	275,491	-104,201	-893
Cash dividends on common stock	-102,200				-102,200
Stock-based compensation	20,823			20,823
Issuance of vested restricted stock granted to employees	0		6	-6
Excess tax benefits from stock-based compensation plan	2,356			2,356
Purchase of unrestricted common stock	-51,426					-51,426
Net income	175,999				175,999
Post-retirement benefit obligation adjustments- net of tax	-157						-157
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest End of Period at Dec. 31, 2013	284,517	0	919	90,985	349,290	-155,627	-1,050
Cash dividends on common stock	-66,999				-66,999
Stock-based compensation	15,577			15,577
Issuance of vested restricted stock granted to employees	0		7	-7
Excess tax benefits from stock-based compensation plan	3,557			3,557
Purchase of unrestricted common stock	-176,660					-176,660
Net income	189,714				189,714
Post-retirement benefit obligation adjustments- net of tax	361						361
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest End of Period at Dec. 31, 2014	$250,067	$0	$926	$110,112	$472,005	($332,287)	($689)

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders Equity (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Post-retirement benefit obligation adjustment, tax expense	$222	($99)	$19

Summary_of_Significant_Account

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Notes)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Nature of Business—CBOE Holdings, Inc. ("CBOE Holdings" or the "Company") is the holding company of registered securities exchanges, subject to oversight by the Securities and Exchange Commission ("SEC"), and a designated contract market under the jurisdiction of the Commodity Futures Trading Commission ("CFTC"). The Company's principal business is operating markets that offer for trading exclusive options on various market indexes (index options) and futures contracts, as well as on non-exclusive "multiply-listed" options, such as options on the stocks of individual corporations (equity options) and options on other exchange-traded products (ETP options), such as exchange-traded funds (ETF options) and exchange-traded notes (ETN options), and certain other index options.
	Basis of Presentation—The consolidated financial statements include the accounts and results of operations of CBOE Holdings and its wholly-owned subsidiaries, including: Chicago Board Options Exchange, Incorporated ("CBOE"), CBOE Futures Exchange, LLC ("CFE"), C2 Options Exchange, Incorporated ("C2"), Market Data Express, LLC, Chicago Options Exchange Building Corporation and DerivaTech Corporation. Inter-company balances and transactions have been eliminated in consolidation. The Company reports the results of its operations in one reporting segment.
	Use of Estimates—The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities and reported amounts of revenues and expenses. On an ongoing basis, management evaluates its estimates based upon historical experience, observance of trends, information available from outside sources and various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ from these estimates under different conditions or assumptions.
	Cash and Cash Equivalents—Cash and cash equivalents include highly liquid investments with maturities of three months or less from the date of purchase. The Company places its cash and cash equivalents with highly-rated financial institutions, limits the amount of credit exposure with any one financial institution and conducts ongoing evaluations of the creditworthiness of the financial institutions with which it does business; therefore concentrations of credit risk are limited. There are no redemption restrictions on the Company's invested cash balances.
	Accounts Receivable—Accounts receivable consists primarily of transaction and regulatory fees from The Options Clearing Corporation, ("OCC"), and the Company's share of distributable revenue receivable from OPRA. Accounts receivable are primarily collected through OCC, and are with large, highly-rated clearing firms; therefore concentrations of credit risk are limited. The Company has no financing-related receivables.
	Prepaid expenses—Prepaid expenses primarily consist of prepaid software maintenance and licensing expenses which are amortized over the respective periods.
	Investments in Affiliates—Investments in affiliates represent investments in OCC, Signal Trading Systems, LLC ("Signal Trading"), IPXI Holdings, LLC ("IPXI") and CBOE Stock Exchange, LLC ("CBSX").
	The investments in OCC and IPXI are accounted for under the cost-method of accounting for investments.
	The investments in Signal Trading and CBSX are accounted for under the equity method.
	Investments in affiliates are periodically reviewed to determine whether any events or changes in circumstances indicate that the investments may be other than temporarily impaired. In the event of impairment, the Company would recognize a loss for the difference between the carrying amount and the estimated fair value of the investment.
	Property and Equipment—Property and equipment are carried at cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method, generally over five to forty years. Leasehold improvements are amortized over the lesser of their estimated useful lives or the remaining term of the applicable leases.
	Property and Equipment—Construction in Progress is capitalized and carried at cost. Upon completion, the projects are placed in service and amortized over the appropriate useful lives, using the straight-line method commencing with the date the asset is placed in service.
	Software Development Work in Progress and Data Processing Software and Other Assets — The Company expenses software development costs as incurred during the preliminary project stage, while capitalizing costs incurred during the application development stage, which includes design, coding, installation and testing activities. Estimated useful lives are three to five years for internally developed and other data processing software and generally are five years or less for other assets.
	Employee Benefit Plans—The funded status of a post retirement benefit plan is recognized in the Consolidated Balance Sheet and 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 changes in actuarial gains and losses and prior service costs in the year in which the changes occur through accumulated other comprehensive loss.
	Commitments and Contingencies—Litigation—The Company accrues loss contingencies when the loss is both probable and estimable. All legal costs incurred in connection with loss contingencies are expensed as service is provided.
	Revenue Recognition—Revenue recognition policies for specific sources of revenue are discussed below:
	Transaction Fees:    Transaction fees are a function of three variables: (1) exchange fee rates; (2) trading volume; and (3) transaction mix between contract type. Transaction fees are assessed on a per contract basis and are considered earned upon the execution of a trade and are recognized on a trade date basis. Transaction fees are presented net of applicable volume discounts. In the event liquidity providers prepay for transaction fees, revenue is recognized based on the attainment of volume thresholds resulting in the amortization of the prepayment over the calendar year.
	Access Fees:    Access fees represent fees assessed to Trading Permit Holders for the opportunity to trade and use other related functions of CBOE, C2 and CFE. Access fees are recognized during the period the service is provided.
	Exchange Services and Other Fees:  Exchange services and other fees include system services, trading floor charges and application revenue. Exchange services and other fees are recognized during the period the service is provided.
	Market Data Fees:    Market data fees include Options Price Reporting Authority ("OPRA") income and fees generated from the Company's market data services. OPRA is a limited liability company consisting of representatives of the member exchanges and is authorized by the SEC to provide consolidated options information. The Company's market data services are provided through CBOE Streaming Markets ("CSM") and other services. OPRA income is allocated based upon the individual exchange's relative volume of total cleared options transactions. The Company receives monthly estimates of OPRA's distributable revenue (See Note 4) and income is distributed on a quarterly basis. Company market data fees represent charges for current and historical options and futures data provided directly by the Company. Market data services are recognized in the period the data is provided.
	Regulatory Fees:   Regulatory fees are primarily based on the number of customer contracts traded on all U.S. options exchanges by Trading Permit Holders and are primarily recognized on a trade-date basis. Under the rules of each of our options exchanges, as required by the SEC, any revenue derived from regulatory fees and fines cannot be used for non-regulatory purposes.
	Concentration of Revenue: All contracts traded on our exchanges must be cleared through clearing members of the OCC. At December 31, 2014, there were one hundred seven Trading Permit Holders that are clearing members of the OCC. Two clearing members accounted for 46% of transaction and other fees collected through the OCC in 2014. The next largest clearing member accounted for approximately 11% of transaction and other fees collected through the OCC. No one Trading Permit Holder using the clearing services of the top two clearing member firms represented more than 42% of transaction and other fees collected through the OCC, for the respective clearing member, in 2014. Should a clearing member withdraw from CBOE, we believe the Trading Permit Holder portion of that clearing member's trading activity would likely transfer to another clearing member.
	The two largest clearing members mentioned above clear the majority of the market-maker sides of transactions at CBOE, C2 and at all of the U.S. options exchanges. If either of these clearing members were to withdraw from the business of market-maker clearing and market-makers were unable to transfer to another clearing member, this could create significant disruption to the U.S. options markets, including ours.
	Advertising Costs—Advertising costs, including print advertising and production costs, product promotion campaigns and seminar, conference convention costs related to trade shows and other industry events and, in prior years, sponsorships with local professional sports organizations, are expensed as incurred or amortized over the respective period. The Company incurred advertising costs of $4.3 million, $5.4 million and $5.3 million for the years ended December 31, 2014, 2013 and 2012, respectively. Advertising costs are included in travel and promotional expenses in the consolidated statements of income.
	Stock-Based Compensation—Stock-based compensation is based on the fair value of the award on the grant date and recognized over the related service period, net of estimated forfeitures. For performance based units, we use the Monte Carlo valuation model method to estimate the fair value of the award.
	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 solely on the technical merits of the position taken or expected to be taken. Interest and penalties are recorded within the provision for income taxes in the Company's consolidated statements of income and are classified on the consolidated balance sheets with the related liability for unrecognized tax benefits. See Note 9 for further discussion of the Company's income taxes.
	Recent Accounting Pronouncements— In April 2014, the FASB issued ASU 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity, an amendment to FASB ASC Topic 205, Presentation of Financial Statements and FASB ASC Topic 360, Property, Plant and Equipment. The update revises the definition of discontinued operations by limiting discontinued operations reporting to disposals of components of an entity that represent strategic shifts that have (or will have) a major effect on an entity's operations and financial results, removing the lack of continuing involvement criteria and requiring discontinued operations reporting for the disposal of an equity method investment that meets the definition of discontinued operations. The update also requires expanded disclosures for discontinued operations, including disclosure of pretax profit or loss of an individually significant component of an entity that does not qualify for discontinued operations reporting. This ASU is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2014. The Company has elected early adoption of the guidance and does not believe it will impact our consolidated balance sheets, statements of income, comprehensive income or cash flows.
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers. This standard outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. In addition, the ASU provides guidance on accounting for certain revenue-related costs including when to capitalize costs associated with obtaining and fulfilling a contract. ASU 2014-09 provides companies with two implementation methods. Companies can choose to apply the standard retrospectively to each prior reporting period presented (full retrospective application) or retrospectively with the cumulative effect of initially applying the standard as an adjustment to the opening balance of retained earnings of the annual reporting period that includes the date of initial application (modified retrospective application). This guidance is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early application is not permitted. The Company is in the process of evaluating this guidance, though we do not expect it will materially impact our consolidated balance sheets, statements of income, comprehensive income or cash flows.

Share_Repurchase_Program

Share Repurchase Program	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Share Repurchase Program	SHARE REPURCHASE PROGRAM
	In 2011, the board of directors approved an initial authorization for the Company to repurchase shares of its outstanding unrestricted common stock of $100 million and approved additional authorizations $100 million in each of 2012, 2013 and 2014 for a total authorization of $400 million. The program permits the Company to purchase shares through a variety of methods, including in the open market or through privately negotiated transactions, in accordance with applicable securities laws. It does not obligate the Company to make any repurchases at any specific time or situation.
	Under the program, for the twelve months ended December 31, 2014, the Company purchased 3,215,246 shares of unrestricted common stock at an average cost per share of $52.35 totaling $168.3 million.
	Since inception of the program through December 31, 2014, the Company has purchased 7,855,070 shares of unrestricted common stock at an average cost per share of $39.51 totaling $310.4 million.

Investment_in_Affiliates

Investment in Affiliates	12 Months Ended
	Dec. 31, 2014
Investments in and Advances to Affiliates, Schedule of Investments [Abstract]
Investments in and Advances to Affiliates, Schedule of Investments [Text Block]	INVESTMENT IN AFFILIATES
	At December 31, 2014 and 2013, the Company's investment in affiliates was comprised of the following (in thousands):
		2014		2013
	Investment in OCC	$	333	$	333
	Investment in Signal Trading	11,900		11,130
	Investment in IPXI	118		3,118
	Investment in CBSX	—		—
	Investment in Affiliates	$	12,351	$	14,581
	The Company holds a 20% investment in OCC which is accounted for under the cost-method of accounting for investments because of the Company's inability to exercise significant influence.
	In May 2010, CBOE acquired a 50% interest in Signal Trading from FlexTrade Systems, Inc. ("FlexTrade"). The joint venture develops and markets a multi-asset front-end order entry system, known as "Pulse," which has a particular emphasis on options trading. The Company assists in the development of the terminals and provides marketing services to the joint venture, which is accounted for under the equity method. We account for the investment in Signal Trading under the equity method due to the substantive participating rights provided to the other limited liability company member, FlexTrade. In the twelve months ended December 31, 2014, the Company recorded contributions to and equity losses in Signal Trading of $2.0 million and $1.2 million, respectively.
	The Company, through DerivaTech Corporation, a wholly-owned subsidiary, acquired a 10.0% interest in IPXI Holdings, LLC ("IPXI") for $2.5 million. The Company contributed an additional $0.6 million in October 2013. In December 2014, the Company recorded an impairment charge of $3.0 million. The impairment was the result of an additional investment in IPXI by an investor at a fair value significantly lower than our original investment. Our investment and equity interest in IPXI as of December 31, 2014 were $0.1 million and approximately 5.0%, respectively.
	The Company currently holds a 49.96% equity interest in CBSX in return for non-cash property contributions. CBSX, which is not a self-regulatory organization, is a stock trading facility of CBOE. CBSX ceased trading operations on April 30, 2014. CBOE is responsible for the compliance and regulation of the CBSX marketplace. In addition, the Company has a services agreement under which it provides financial, accounting and technology support.

Related_Parties

Related Parties	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions Disclosure [Text Block]	RELATED PARTIES
	The Company collected transaction and other fees of $687.5 million, $610.3 million and $544.3 million in the years ended December 31, 2014, 2013 and 2012, respectively, by drawing on accounts of CBOE and C2 market participants held at OCC. The amounts collected by OCC for CBOE included $121.4 million, $99.7 million and $96.1 million of marketing fees during the years ended December 31, 2014, 2013 and 2012, respectively. Additionally, the Company collected transaction and other fees of $84.7 million and $65.7 million in the years ended December 31, 2014 and 2013, respectively, by drawing on accounts of CFE market participants held at OCC. In 2012, CFE collections were included in CBOE and C2 collections. The Company had a receivable due from OCC of $59.8 million and $48.6 million at December 31, 2014 and 2013, respectively.
	OPRA is a limited liability company consisting of representatives of the member exchanges and is authorized by the SEC to provide consolidated options information. This information is provided by the exchanges and is sold to market data vendors, outside news services and customers. OPRA's operating income is distributed among the exchanges based on their relative volume of total cleared options transactions. The Company's share of OPRA operating income was $15.1 million, $12.9 million and $15.0 million during the years ended December 31, 2014, 2013 and 2012, respectively. The Company had a receivable from OPRA of $4.2 million and $3.9 million at December 31, 2014 and 2013, respectively.
	The Company incurred re-billable expenses on behalf of CBSX for expenses such as employee costs, computer equipment and software of $2.4 million, $4.6 million and $3.7 million during the years ended December 31, 2014, 2013 and 2012, respectively. These amounts are included as a reduction of the underlying expenses. The Company had a receivable from CBSX of $0.4 million at December 31, 2013, respectively. CBSX ceased trading operations on April 30, 2014, therefore, we did not have a material receivable balance at December 31, 2014.
	Options Regulatory Surveillance Authority ("ORSA") is responsible for conducting insider trading investigations related to options on behalf of all options exchanges. CBOE through December 2014 was the Regulatory Services Provider under a plan entered into by the options exchanges and approved by the SEC to administer ORSA. Effective January 1, 2015, the ORSA policy committee delegated the operation of the ORSA Plan facility to FINRA, and FINRA became the service provider under the Regulatory Services Agreement. During the year, the Company incurred re-billable expenses on behalf of ORSA for expenses such as employee costs, occupancy and operating systems of $2.7 million, $2.3 million and $2.1 million, during the years ended December 31, 2014, 2013 and 2012, respectively. These amounts were included as a reduction of the underlying expenses. The Company had a receivable due from ORSA of $1.2 million and $1.2 million at December 31, 2014 and 2013, respectively.

Accounts_Payable_and_Accured_L

Accounts Payable and Accured Liabilities	12 Months Ended
	Dec. 31, 2014
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accounts Payable and Accrued Liabilities Disclosure [Text Block]	ACCOUNTS PAYABLE AND ACCRUED LIABILITIES
	At December 31, 2014 and 2013, accounts payable and accrued liabilities consisted of the following (in thousands):
		2014		2013
	Compensation and benefit related liabilities	$	23,032	$	22,193
	Royalties	17,624		13,512
	Accounts payable	2,779		4,219
	Facilities	1,942		1,824
	Legal	1,355		1,602
	Market Linkage	1,183		1,157
	Purchase of unrestricted common stock (1)	1,159		1,937
	Other	9,492		6,514
	Total	$	58,566	$	52,958
	(1) Reflects shares purchased at the end of the period that are not settled until three trading days after the trade occurs.

Marketing_Fee

Marketing Fee	12 Months Ended
	Dec. 31, 2014
Marketing Fee [Abstract]
Marketing Fees [Text Block]	MARKETING FEE
	The Company facilitates the collection and payment of marketing fees assessed on certain trades taking place at CBOE. Funds resulting from the marketing fees are made available to Designated Primary Market-Makers and Preferred Market-Makers as an economic inducement to route orders to CBOE. Pursuant to ASC 605-45, Revenue Recognition—Principal Agent Considerations, the Company reflects the assessments and payments on a net basis, with no impact on revenues or expenses.
	As of December 31, 2014 and 2013, amounts assessed by the Company on behalf of others included in current assets totaled $10.7 million and $8.9 million, respectively, and payments due to others included in current liabilities totaled $11.2 million and $9.4 million, respectively.

Deferred_Revenue

Deferred Revenue	12 Months Ended
	Dec. 31, 2014
Deferred Revenue [Abstract]
Deferred Revenue Disclosure [Text Block]	DEFERRED REVENUE
	The following tables summarize the activity in deferred revenue for the years ended December 31, 2014 and 2013.
	(in thousands)	Balance at		Cash		Revenue			Balance at
		December 31,		Additions		Recognition			December 31,
		2013							2014
	Liquidity provider sliding scale	$	—	$	15,800	$	(15,800	)	$	—
	Other, net	1,100		11,429		(10,541		)	1,988
	Total deferred revenue	$	1,100	$	27,229	$	(26,341	)	$	1,988
	(in thousands)	Balance at		Cash		Revenue			Balance at
		December 31,		Additions		Recognition			December 31,
		2012							2013
	Liquidity provider sliding scale	$		$	29,232	$	(29,232	)	$	—
	Other, net	1,084		7,348		(7,332		)	1,100
	Total deferred revenue	$	1,084	$	36,580	$	(36,564	)	$	1,100
	Liquidity providers are eligible to participate in the sliding scale program, which involves prepayment of transaction fees, and receive reduced fees based on the achievement of certain volume thresholds within a month. The prepayment of 2014 and 2013 transaction fees totaled $15.8 million and $29.2 million, respectively. These amounts were amortized and recorded as transaction fees over the respective twelve month periods.

Employee_Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Postemployment Benefits Disclosure [Text Block]	EMPLOYEE BENEFITS
	Employees are eligible to participate in the Chicago Board Options Exchange SMART Plan ("SMART Plan"). The SMART Plan is a defined contribution plan, which is qualified under Internal Revenue Code Section 401(k). The Company contributed $4.5 million, $4.0 million and $3.9 million to the SMART Plan for each of the years ended December 31, 2014, 2013 and 2012, respectively.
	Eligible employees may participate in the Supplemental Employee Retirement Plan, Executive Retirement Plan and Deferred Compensation Plan. Each plan is a defined contribution plan that is non-qualified by Internal Revenue Code regulations. The Company contributed $1.5 million, $1.6 million and $1.4 million to the above plans for the years ended December 31, 2014, 2013 and 2012, respectively.
	The Company has a post-retirement medical plan for certain former members of senior management. The Company recorded immaterial post-retirement benefits expense for the years ended December 31, 2014, 2013 and 2012, resulting from the amortization of service costs and actuarial expense included in accumulated other comprehensive loss at December 31, 2014, 2013 and 2012.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	INCOME TAXES
	A reconciliation of the statutory federal income tax rate to the effective income tax rate for the years ended December 31, 2014, 2013 and 2012 is as follows:
		2014			2013			2012
	Statutory federal income tax rate	35	%		35	%		35	%
	State income tax rate, net of federal income tax effect	3.5			3.6			4.8
	Section 199 deductions	(1.7	)		(2.1	)		(7.5	)
	Other, net	1.9			1.5			2.8
	Effective income tax rate	38.7	%		38	%		35.1	%
	During the twelve months ended December 31, 2012, the Company filed amended returns for 2008, 2009 and 2010 and completed its return for 2011 and recognized, as a discrete item, in the aggregate, a $12.9 million net benefit for a Section 199 deduction for U.S. production activities which encompasses all personal property, including computer software for prior year periods.
	The components of income tax expense for the years ended December 31, 2014, 2013 and 2012 are as follows (in thousands):
		2014				2013				2012
	Current:
	Federal	$	95,946			$	93,844			$	65,054
	State	24,327				20,958				20,597
	Total current	120,273				114,802				85,651
	Deferred:
	Federal	1,955				(4,636		)		406
	State	(2,245		)		(2,509		)		(901		)
	Total deferred	(290		)		(7,145		)		(495		)
	Total	$	119,983			$	107,657			$	85,156
	At December 31, 2014 and 2013, the net deferred income tax liability is as follows (in thousands):
		2014				2013
	Deferred tax assets	$	26,962			$	25,144
	Deferred tax liabilities	(40,639		)		(38,889		)
	Net deferred income tax liability	$	(13,677	)		$	(13,745	)
	The tax effect of temporary differences giving rise to significant portions of deferred tax assets and liabilities at December 31, 2014 and 2013 are presented below (in thousands):
		2014				2013
	Deferred tax assets:
	Intangibles	$	44			$	50
	Accrued compensation and benefits	9,347				11,233
	Property, equipment and technology, net	596				697
	Investment in affiliates	6,325				6,158
	Other	10,650				7,006
	Total deferred tax assets	26,962				25,144
	Deferred tax liabilities:
	Property, equipment and technology, net	(37,851		)		(36,180		)
	Investment in affiliates	(1,696		)		(1,683		)
	Prepaid	(1,080		)		(1,027		)
	Other	(12		)		1
	Total deferred tax liabilities	(40,639		)		(38,889		)
	Net deferred tax liabilities	$	(13,677	)		$	(13,745	)
	The net deferred tax liabilities are classified as long-term liabilities in the Consolidated Balance Sheets at December 31, 2014 and 2013.
	A reconciliation of the beginning and ending uncertain tax positions, excluding interest and penalties, is as follows (in thousands):
		2014				2013				2012
	Balance as of January 1	$	26,745			$	19,493			$	12,185
	Gross increases on tax positions in prior period	2,828				549				3,401
	Gross decreases on tax positions in prior period	(1,053		)		(18		)		(833		)
	Gross increases on tax positions in current period	8,113				7,270				4,740
	Lapse of statute of limitations	(1,204		)		(549		)		—
	Balance as of December 31	$	35,429			$	26,745			$	19,493
	As of December 31, 2014, 2013 and 2012, the Company had $35.4 million, $26.7 million and $19.5 million, respectively, of uncertain tax positions excluding interest and penalties, which, if recognized in the future, would affect the annual effective income tax rate. Reductions to uncertain tax positions from the lapse of the applicable statutes of limitations during the next twelve months are estimated to be approximately $15.9 million, not including any potential new additions.
	Estimated interest costs and penalties are classified as part of the provision for income taxes in the Company's consolidated statements of income and were $2.1 million, $1.8 million and $0.6 million for the periods ended December 31, 2014, 2013 and 2012, respectively. Accrued interest and penalties were $5.3 million, $3.2 million and $1.4 million as of December 31, 2014, 2013 and 2012, respectively.
	The Company is subject to U.S. federal tax, Illinois, New Jersey, and New York state taxes and Washington, D.C. taxes, as well as taxes in other local jurisdictions. The Company has open tax years from 2007 on for New York, 2008 on for Federal, 2010 on for New Jersey, and 2011 on for Illinois and Washington, D.C. The Internal Revenue Service is currently auditing 2010 and is looking at specific line items from 2008 to 2013 due to the filing by the Company of amended returns containing the recognition of certain credits and deductions. The Illinois Department of Revenue has informed the Company they will be auditing 2011 and 2012 tax years, the New York State Department of Taxation and Finance is currently auditing the 2007 through 2012 tax years and the New Jersey Division of Taxation is currently auditing the 2010 through 2012 tax years.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Text Block]	FAIR VALUE MEASUREMENTS
	Fair value is the price that would be received upon sale of an asset or paid upon transfer of a liability in an orderly transaction between market participants at the measurement date and in the principal or most advantageous market for that asset or liability. The fair value should be calculated based on assumptions that market participants would use in pricing the asset or liability, not on assumptions specific to the entity. In addition, the fair value of liabilities should include consideration of non-performance risk, including the Company’s own credit risk.
	The Company applied Financial Accounting Standards Board ("FASB") ASC 820, Fair Value Measurement and Disclosure, which provides guidance for using fair value to measure assets and liabilities by defining fair value and establishing the framework for measuring fair value. ASC 820 applies to financial and nonfinancial instruments that are measured and reported on a fair value basis. The three-level hierarchy of fair value measurements is based on whether the inputs to those measurements are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Company’s market assumptions. The fair-value hierarchy requires the use of observable market data when available and consists of the following levels:
	•	Level 1—Unadjusted inputs based on quoted markets for identical assets or liabilities.
	•	Level 2—Observable inputs, either direct or indirect, not including Level 1, corroborated by market data or based upon quoted prices in non-active markets.
	•	Level 3—Unobservable inputs that reflect management’s best assumptions of what market participants would use in valuing the asset or liability.
	The Company has included a tabular disclosure for financial assets that are measured at fair value on a recurring basis in the consolidated balance sheet as of December 31, 2014 and 2013. The Company holds no financial liabilities that are measured at fair value on a recurring basis.
	(amounts in thousands)	Level 1		Level 2		Level 3		Total
	Assets at fair value:
	Money market funds	$	135,000	—		—		$	135,000
	Total assets at fair value at December 31, 2014	$	135,000	$	—	$	—	$	135,000
	(amounts in thousands)	Level 1		Level 2		Level 3		Total
	Assets at fair value:
	Money market funds	$	207,000	—		—		$	207,000
	Total assets at fair value at December 31, 2013	$	207,000	$	—	$	—	$	207,000
	The Company, through DerivaTech Corporation, a wholly-owned subsidiary, acquired a 10.0% interest in IPXI Holdings, LLC ("IPXI") for $2.5 million. The Company contributed an additional $0.6 million in October 2013. The investment, measured at fair value on a non-recurring basis, is classified as level 3 as the fair value was based on both observable and unobservable inputs. In December 2014, the Company recorded an impairment charge of $3.0 million. The impairment was the result of an additional investment in IPXI by an investor at a fair value significantly lower than our original investment. Our investment and equity interest in IPXI as of December 31, 2014 were valued at $0.1 million and approximately 5.0%, respectively.

Commitments_and_Contigencies

Commitments and Contigencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	COMMITMENTS AND CONTINGENCIES
	As of December 31, 2014, the end of the period covered by this report, the Company was subject to the various legal proceedings and claims discussed below, as well as certain other legal proceedings and claims that have not been fully resolved and that have arisen in the ordinary course of business.
	The Company reviews its legal proceedings and claims, regulatory reviews and inspections and other legal proceedings on an ongoing basis and follows appropriate accounting guidance when making accrual and disclosure decisions. The Company establishes accruals for those contingencies where the incurrence of a loss is probable and can be reasonably estimated, and we disclose the amount accrued and the amount of a reasonably possible loss in excess of the amount accrued, if such disclosure is necessary for our financial statements to not be misleading. The Company does not record liabilities when the likelihood that the liability has been incurred is probable, but the amount cannot be reasonably estimated, or when the liability is believed to be only reasonably possible or remote. The Company's assessment of whether a loss is reasonably possible or probable is based on its assessment of the ultimate outcome of the matter following all appeals.
	As of December 31, 2014, the Company does not believe that there is a reasonable possibility that any material loss exceeding the amounts already recognized for these reviews, inspections or other legal proceedings, if any, has been incurred. While the consequences of certain unresolved proceedings are not presently determinable, the outcome of any litigation is inherently uncertain and an adverse outcome from certain matters could have a material effect on our earnings in any given reporting period. However, in the opinion of management, the ultimate liability is not expected to have a material effect on our financial position, liquidity or capital resources.
	Patent Litigation
	ISE -- QRM
	On November 12, 2012, CBOE brought suit against International Securities Exchange, LLC ("ISE") in the United States District Court for the Northern District of Illinois alleging that ISE infringes three of its patents (United States Patent Nos. 7,356,498; 7,980,457; and 8,266,044 (the “QRM patents”)) related to quote risk monitor ("QRM") technology. CBOE has requested injunctive relief and monetary damages. On February 20, 2013, the court ruled that the case be transferred to the United States District Court for the Southern District of New York.  On October 31, 2013, the court stayed the litigation pending resolution of Covered Business Method ("CBM") Patent Reviews at the United States Patent and Trademark Office ("USPTO") that ISE had petitioned for. On March 4, 2014, the USPTO instituted CBM Patent Reviews on CBOE’s three QRM patents. In the CBM Patent Reviews, ISE has alleged that CBOE’s three QRM patents are invalid because they are directed to subject matter that is not eligible for patent protection. On May 22, 2014, the USPTO instituted Inter Parties Review (“IPR”) Proceedings, which ISE had petitioned for, on some but not all claims of two of CBOE’s QRM patents (United States Patent Nos. 7,356,498 and 7,980,457).  In the IPR Proceedings, ISE has alleged that claims of two of CBOE’s QRM patents are invalid because they are directed to subject matter that is either anticipated or obvious in view of the prior art. Both the CBM Patent Reviews and IPR Proceedings are adjudicated by the Patent Trial and Appeal Board of the USPTO.
	Lanier Litigation
	On May 23, 2014, Harold R. Lanier sued 14 securities exchanges, including CBOE, in the United States District Court for the Southern District of New York on behalf of himself and a putative class consisting of all persons in the United States who entered into contracts to receive market data through certain data plans at any time since May 19, 2008 to the present.  The complaint alleges that the market data provided under the CQ Plan and CTA Plans was inferior to the data that the exchanges provided to those that directly receive other data from the exchanges, which the plaintiffs allege is a breach of their “subscriber contracts” and a violation of the exchanges’ obligations under the CQ and CTA Plans.  The plaintiffs seek monetary and injunctive relief.  On May 30, 2014, Mr. Lanier filed two additional suits in the same Court, alleging substantially the same claims and requesting for the same types of relief against the exchanges who participate in the UTP and the OPRA data plans.  CBOE is a defendant in each of these suits, while C2 is only a defendant in the suit regarding the OPRA Plan.
	Other
	As a self-regulatory organization under the jurisdiction of the SEC, with respect to CBOE and C2, and as a designated contract market under the jurisdiction of the CFTC, with respect to CFE, we are subject to routine reviews and inspections by the SEC and the CFTC.
	We are also currently a party to various other legal proceedings in addition to those already mentioned. Management does not believe that the outcome of any of these other reviews, inspections or other legal proceedings will have a material impact on our consolidated financial position, results of operations or cash flows.
	Leases and Other Obligations
	The Company leases facilities with lease terms remaining from 8 months to 31 months as of December 31, 2014. Total rent expense related to these lease obligations, reflected in data processing and facilities costs line items on the Consolidated Statements of Income, for the years ended December 31, 2014, 2013 and 2012 were $3.8 million, $3.0 million and $3.5 million, respectively. Future minimum payments for our operating leases and contractual obligations are as follows at December 31, 2014 (in thousands):
	Year	Operating		Contractual Obligations		Total
		Leases
	2015	$	2,811	18,157		$	20,968
	2016	2,628		20,463		23,091
	2017	696		23,057		23,753
	2018	—		20,070		20,070
	2019	—		20,084		20,084
	Total	$	6,135	$	101,831	$	107,966

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2014
Share-based Compensation [Abstract]
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	STOCK-BASED COMPENSATION
	Stock-based compensation is based on the fair value of the award on the date of grant, which is recognized over the related service period, net of estimated forfeitures. The service period is the period over which the related service is performed, which is generally the same as the vesting period.
	The board amended and restated the CBOE Holdings, Inc. Long Term Incentive Plan (the "LTIP"), effective upon receiving stockholder approval, which was received at the May 17, 2011 annual meeting of stockholders. The LTIP provides that an aggregate of 4,248,497 shares of the Company's common stock are reserved for issuance to participants under the LTIP.
	The Compensation Committee of the Company's board of directors administers the LTIP and may designate any of the following as a participant under the LTIP: any officer or other employee of the Company or its affiliates or individuals engaged to become an officer or employee and non-employee directors of the Company. The LTIP permits the granting of non-qualified stock options, restricted stock, restricted stock units, incentive compensation awards or any combination of the foregoing. The Compensation Committee has the authority and complete discretion to prescribe, amend and rescind rules and regulations relating to the LTIP, select participants and to determine the form and terms of any awards.
	On February 19, 2014, the Company granted awards that covered 206,192 shares of stock, consisting of 45,168 shares of restricted stock and 161,024 restricted stock units ("RSUs"), each of which entitles the holders to one share of common stock upon vesting, to certain officers and employees at a fair value of $55.35 per share. The RSUs vest ratably over three years, with one-third vesting on each anniversary of the grant date, and vesting accelerates upon the occurrence of a change in control. Unvested restricted stock units will be forfeited if the officer or employee leaves the company prior to the applicable vesting date, except in limited circumstances. The restricted stock units have no voting rights but are able to participate in the payment of dividends.
	In addition, on February 19, 2014, the Company granted 47,470 RSUs that are contingent on the achievement of performance conditions including 23,735 at a fair value of $55.35 per RSU related to earnings per share during the performance period and 23,735 RSUs at a fair value of $77.00 per RSU, related to total shareholder return during the performance period. The Company used the Monte Carlo valuation model method to estimate the fair value of the total shareholder return RSUs which incorporated the following assumptions: risk free interest rate (0.69%), three-year volatility (24.8%) and three-year correlation with S&P 500 Index (0.56). Each of these performance shares has a performance condition under which the number of units ultimately awarded will vary from 0% to 200% of the original grant, with each unit representing the contingent right to receive one share of our common stock. The vesting period for the shares contingent on the achievement of performance is three years. For each of the performance awards, the RSU will be settled in shares of our common stock following vesting of the restricted stock unit assuming that the participant has been continuously employed during the vesting period, subject to acceleration in the event of a change of control of the Company or in the event of a participant’s earlier death, disability or qualified retirement. Participants shall have no voting rights with respect to shares until the issuance of the shares of stock. Dividends are accrued by the Company and will be paid once the RSUs contingent on the achievement of performance conditions vest.
	On May 22, 2014, the Company granted 18,240 shares of restricted stock, at a fair value of $49.36 per share, to the non-employee members of the board of directors. The shares have a one-year vesting period and vesting accelerates upon the occurrence of a change in control of the Company. Unvested portions of the restricted stock will be forfeited if the director leaves the company prior to the applicable vesting date.
	For the years ended December 31, 2014, 2013 and 2012, the Company recognized $15.6 million, $20.8 million and $12.3 million, respectively, of stock-based compensation expense related to restricted stock. For the twelve months ended December 31, 2014, 2013 and 2012, the Company recorded $2.5 million, $4.0 million and $0.3 million, respectively, to recognize accelerated stock-based compensation. The accelerated stock-based compensation expense, in 2014 and 2013, is primarily for certain executives due to provisions contained in their employment arrangements and, in 2012, departures from the board of directors.
	The activity in the Company's restricted stock, restricted stock units and performance shares for the year ended December 31, 2014 was as follows:
		Number of Shares		Weighted Average
		of Restricted		Grant-Date Fair
		Stock		Value
	Unvested restricted stock at January 1, 2014	708,221		$	33.41
	Granted	271,902		56.84
	Vested	(553,639	)	33.26
	Forfeited	(11,735	)	42.05
	Unvested restricted stock at December 31, 2014	414,749		$	46.44
	As of December 31, 2014, the Company had unrecognized stock-based compensation expense of $12.3 million related to outstanding restricted stock. The remaining unrecognized stock-based compensation is expected to be recognized over a weighted average period of 1.4 years. The Company is projecting a forfeiture rate in the range of 2% to 5%. The total fair value of shares vested during the year ended December 31, 2014 was $18.4 million.

Net_Income_per_Common_Share

Net Income per Common Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	NET INCOME PER COMMON SHARE
	The computation of basic net income allocated to common stockholders is calculated by reducing net income for the period by dividends paid or declared and undistributed net income for the period that are allocated to participating securities to arrive at net income allocated to common stockholders. Net income allocated to common stockholders is divided by the weighted average number of common shares outstanding during the period to determine net income per share allocated to common stockholders.
	The computation of diluted earnings per share is calculated by dividing net income allocated to common stockholders by the sum of the weighted average number of common shares outstanding plus all additional common shares that would have been outstanding if the potentially dilutive common shares had been issued. The dilutive effect is calculated using the more dilutive of the two-class or treasury stock method.
	The following table reconciles net income applicable to common stockholders and the number of shares used to calculate the basic and diluted net income per common share for the for the years ended December 31, 2014, 2013 and 2012:
	(in thousands, except per share amounts)	2014			2013			2012
	Basic EPS Numerator:
	Net Income	$	189,714		$	175,999		$	157,395
	Less: Earnings allocated to participating securities	(1,322		)	(2,136		)	(2,141		)
	Net Income allocated to common stockholders	$	188,392		$	173,863		$	155,254
	Basic EPS Denominator:
	Weighted average shares outstanding	85,406			87,331			87,460
	Basic net income per common share	$	2.21		$	1.99		$	1.78
	Diluted EPS Numerator:
	Net Income	$	189,714		$	175,999		$	157,395
	Less: Earnings allocated to participating securities	(1,322		)	(2,136		)	(2,141		)
	Net Income allocated to common stockholders	$	188,392		$	173,863		$	155,254
	Diluted EPS Denominator:
	Weighted average shares outstanding	85,406			87,331			87,460
	Dilutive common shares issued under restricted stock program	—			—			—
	Diluted net income per common share	$	2.21		$	1.99		$	1.78
	For the periods presented, the Company did not have shares of restricted stock or restricted stock units that would have an anti-dilutive effect on the computation of diluted net income per common share.

Quarterly_Data

Quarterly Data	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information [Text Block]	QUARTERLY DATA (unaudited)
	Year ended December 31, 2014 (in thousands)	First		Second		Third		Fourth		Year
		Quarter		Quarter		Quarter		Quarter
	Operating revenues	$	157,885	$	143,942	$	148,910	$	166,488	$	617,225
	Operating expenses	75,847		74,226		73,826		79,525		303,424
	Operating income	82,038		69,716		75,084		86,963		313,801
	Net income	$	49,024	$	42,981	$	48,366	$	49,342	$	189,714
	Net income allocated to common stockholders	$	48,528	$	42,598	$	48,146	$	49,119	$	188,392
	Diluted—net income per share to common stockholders	$	0.56	$	0.5	$	0.57	$	0.58	$	2.21
	Year ended December 31, 2013 (in thousands)	First		Second		Third		Fourth		Year
		Quarter		Quarter		Quarter		Quarter
	Operating revenues	$	142,705	$	150,772	$	136,743	$	141,830	$	572,050
	Operating expenses	73,275		75,414		68,316		69,231		286,236
	Operating income	69,430		75,358		68,427		72,599		285,814
	Net income	$	42,373	$	46,161	$	41,356	$	46,110	$	175,999
	Net income allocated to common stockholders	$	41,789	$	45,477	$	40,955	$	45,643	$	173,863
	Diluted—net income per share to common stockholders	$	0.48	$	0.52	$	0.47	$	0.52	$	1.99
	•	In the first quarter of 2014, the Company recorded accelerated stock-based compensation expense of $2.5 million for certain executives due to provisions contained in their employment arrangements.
	•	In the fourth quarter of 2014, the Company recorded $1.9 million in severance resulting from the outsourcing of certain regulatory services to FINRA.
	•	In the fourth quarter of 2014, the Company recorded a $3.0 million impairment of the investment in IXPI.
	•	In the first quarter of 2013, the Company recorded accelerated stock-based compensation expense of $3.2 million for certain executives due to provisions contained in their employment arrangements.
	•	In the second quarter of 2013, the Company recorded $1.0 million of expense for an estimated liability related to an SEC investigation of CBOE's compliance with its obligations as a self-regulatory organization under the federal securities laws.
	•	In the second quarter of 2013, the Company recorded grants to the Chief Executive Officer and President and Chief Operating Officer totaling $2.5 million, of which 50% vested upon grant. In addition, the Company recorded accelerated stock-based compensation of $0.8 million to recognize the remaining value of stock grants awarded to employees in its regulatory division who will no longer receive stock-based compensation.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events [Text Block]	SUBSEQUENT EVENTS
	On February 4, 2015, the Company's board of directors declared a quarterly cash dividend of $0.21 per share. The dividend is payable on March 20, 2015 to stockholders of record at the close of business on February 27, 2015.
	On February 19, 2015, the Company granted 205,030 restricted stock units to certain officers and employees at a fair value of $61.96 per share, the closing price of the Company's stock on the grant date. The shares have a three year vesting period based on achievement of certain service, performance and/or market conditions and vesting accelerates upon the occurrence of a change in control of the Company or in the event of earlier death, disability or qualified retirement.

Summary_of_Significant_Account1

Summary of Significant Accounting (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Nature of Business—CBOE Holdings, Inc. ("CBOE Holdings" or the "Company") is the holding company of registered securities exchanges, subject to oversight by the Securities and Exchange Commission ("SEC"), and a designated contract market under the jurisdiction of the Commodity Futures Trading Commission ("CFTC"). The Company's principal business is operating markets that offer for trading exclusive options on various market indexes (index options) and futures contracts, as well as on non-exclusive "multiply-listed" options, such as options on the stocks of individual corporations (equity options) and options on other exchange-traded products (ETP options), such as exchange-traded funds (ETF options) and exchange-traded notes (ETN options), and certain other index options.
Consolidation, Policy [Policy Text Block]	Basis of Presentation—The consolidated financial statements include the accounts and results of operations of CBOE Holdings and its wholly-owned subsidiaries, including: Chicago Board Options Exchange, Incorporated ("CBOE"), CBOE Futures Exchange, LLC ("CFE"), C2 Options Exchange, Incorporated ("C2"), Market Data Express, LLC, Chicago Options Exchange Building Corporation and DerivaTech Corporation. Inter-company balances and transactions have been eliminated in consolidation. The Company reports the results of its operations in one reporting segment.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates—The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities and reported amounts of revenues and expenses. On an ongoing basis, management evaluates its estimates based upon historical experience, observance of trends, information available from outside sources and various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ from these estimates under different conditions or assumptions.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents—Cash and cash equivalents include highly liquid investments with maturities of three months or less from the date of purchase. The Company places its cash and cash equivalents with highly-rated financial institutions, limits the amount of credit exposure with any one financial institution and conducts ongoing evaluations of the creditworthiness of the financial institutions with which it does business; therefore concentrations of credit risk are limited. There are no redemption restrictions on the Company's invested cash balances.
Receivables, Policy [Policy Text Block]	Accounts Receivable—Accounts receivable consists primarily of transaction and regulatory fees from The Options Clearing Corporation, ("OCC"), and the Company's share of distributable revenue receivable from OPRA. Accounts receivable are primarily collected through OCC, and are with large, highly-rated clearing firms; therefore concentrations of credit risk are limited. The Company has no financing-related receivables.
Maintenance Cost, Policy [Policy Text Block]	Prepaid expenses—Prepaid expenses primarily consist of prepaid software maintenance and licensing expenses which are amortized over the respective periods.
Investments in and Advances to Affiliates [Table Text Block]	Investments in Affiliates—Investments in affiliates represent investments in OCC, Signal Trading Systems, LLC ("Signal Trading"), IPXI Holdings, LLC ("IPXI") and CBOE Stock Exchange, LLC ("CBSX").
	The investments in OCC and IPXI are accounted for under the cost-method of accounting for investments.
	The investments in Signal Trading and CBSX are accounted for under the equity method.
	Investments in affiliates are periodically reviewed to determine whether any events or changes in circumstances indicate that the investments may be other than temporarily impaired. In the event of impairment, the Company would recognize a loss for the difference between the carrying amount and the estimated fair value of the investment.
Property, Plant and Equipment, Policy [Policy Text Block]	Property and Equipment—Property and equipment are carried at cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method, generally over five to forty years. Leasehold improvements are amortized over the lesser of their estimated useful lives or the remaining term of the applicable leases.
Property and Equipment Construction In Progress [Policy Text Block]	Property and Equipment—Construction in Progress is capitalized and carried at cost. Upon completion, the projects are placed in service and amortized over the appropriate useful lives, using the straight-line method commencing with the date the asset is placed in service.
Internal Use Software, Policy [Policy Text Block]	Software Development Work in Progress and Data Processing Software and Other Assets — The Company expenses software development costs as incurred during the preliminary project stage, while capitalizing costs incurred during the application development stage, which includes design, coding, installation and testing activities. Estimated useful lives are three to five years for internally developed and other data processing software and generally are five years or less for other assets.
Pension and Other Postretirement Plans, Nonpension Benefits, Policy [Policy Text Block]	Employee Benefit Plans—The funded status of a post retirement benefit plan is recognized in the Consolidated Balance Sheet and 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 changes in actuarial gains and losses and prior service costs in the year in which the changes occur through accumulated other comprehensive loss.
Commitments and Contingencies, Policy [Policy Text Block]	Commitments and Contingencies—Litigation—The Company accrues loss contingencies when the loss is both probable and estimable. All legal costs incurred in connection with loss contingencies are expensed as service is provided.
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition—Revenue recognition policies for specific sources of revenue are discussed below:
	Transaction Fees:    Transaction fees are a function of three variables: (1) exchange fee rates; (2) trading volume; and (3) transaction mix between contract type. Transaction fees are assessed on a per contract basis and are considered earned upon the execution of a trade and are recognized on a trade date basis. Transaction fees are presented net of applicable volume discounts. In the event liquidity providers prepay for transaction fees, revenue is recognized based on the attainment of volume thresholds resulting in the amortization of the prepayment over the calendar year.
	Access Fees:    Access fees represent fees assessed to Trading Permit Holders for the opportunity to trade and use other related functions of CBOE, C2 and CFE. Access fees are recognized during the period the service is provided.
	Exchange Services and Other Fees:  Exchange services and other fees include system services, trading floor charges and application revenue. Exchange services and other fees are recognized during the period the service is provided.
	Market Data Fees:    Market data fees include Options Price Reporting Authority ("OPRA") income and fees generated from the Company's market data services. OPRA is a limited liability company consisting of representatives of the member exchanges and is authorized by the SEC to provide consolidated options information. The Company's market data services are provided through CBOE Streaming Markets ("CSM") and other services. OPRA income is allocated based upon the individual exchange's relative volume of total cleared options transactions. The Company receives monthly estimates of OPRA's distributable revenue (See Note 4) and income is distributed on a quarterly basis. Company market data fees represent charges for current and historical options and futures data provided directly by the Company. Market data services are recognized in the period the data is provided.
	Regulatory Fees:   Regulatory fees are primarily based on the number of customer contracts traded on all U.S. options exchanges by Trading Permit Holders and are primarily recognized on a trade-date basis. Under the rules of each of our options exchanges, as required by the SEC, any revenue derived from regulatory fees and fines cannot be used for non-regulatory purposes.
	Concentration of Revenue: All contracts traded on our exchanges must be cleared through clearing members of the OCC. At December 31, 2014, there were one hundred seven Trading Permit Holders that are clearing members of the OCC. Two clearing members accounted for 46% of transaction and other fees collected through the OCC in 2014. The next largest clearing member accounted for approximately 11% of transaction and other fees collected through the OCC. No one Trading Permit Holder using the clearing services of the top two clearing member firms represented more than 42% of transaction and other fees collected through the OCC, for the respective clearing member, in 2014. Should a clearing member withdraw from CBOE, we believe the Trading Permit Holder portion of that clearing member's trading activity would likely transfer to another clearing member.
	The two largest clearing members mentioned above clear the majority of the market-maker sides of transactions at CBOE, C2 and at all of the U.S. options exchanges. If either of these clearing members were to withdraw from the business of market-maker clearing and market-makers were unable to transfer to another clearing member, this could create significant disruption to the U.S. options markets, including ours.
Advertising Costs, Policy [Policy Text Block]	Advertising Costs—Advertising costs, including print advertising and production costs, product promotion campaigns and seminar, conference convention costs related to trade shows and other industry events and, in prior years, sponsorships with local professional sports organizations, are expensed as incurred or amortized over the respective period. The Company incurred advertising costs of $4.3 million, $5.4 million and $5.3 million for the years ended December 31, 2014, 2013 and 2012, respectively. Advertising costs are included in travel and promotional expenses in the consolidated statements of income
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	Stock-Based Compensation—Stock-based compensation is based on the fair value of the award on the grant date and recognized over the related service period, net of estimated forfeitures. For performance based units, we use the Monte Carlo valuation model method to estimate the fair value of the award.
Income Tax, Policy [Policy Text Block]	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 solely on the technical merits of the position taken or expected to be taken. Interest and penalties are recorded within the provision for income taxes in the Company's consolidated statements of income and are classified on the consolidated balance sheets with the related liability for unrecognized tax benefits. See Note 9 for further discussion of the Company's income taxes.
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	Recent Accounting Pronouncements— In April 2014, the FASB issued ASU 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity, an amendment to FASB ASC Topic 205, Presentation of Financial Statements and FASB ASC Topic 360, Property, Plant and Equipment. The update revises the definition of discontinued operations by limiting discontinued operations reporting to disposals of components of an entity that represent strategic shifts that have (or will have) a major effect on an entity's operations and financial results, removing the lack of continuing involvement criteria and requiring discontinued operations reporting for the disposal of an equity method investment that meets the definition of discontinued operations. The update also requires expanded disclosures for discontinued operations, including disclosure of pretax profit or loss of an individually significant component of an entity that does not qualify for discontinued operations reporting. This ASU is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2014. The Company has elected early adoption of the guidance and does not believe it will impact our consolidated balance sheets, statements of income, comprehensive income or cash flows.
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers. This standard outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. In addition, the ASU provides guidance on accounting for certain revenue-related costs including when to capitalize costs associated with obtaining and fulfilling a contract. ASU 2014-09 provides companies with two implementation methods. Companies can choose to apply the standard retrospectively to each prior reporting period presented (full retrospective application) or retrospectively with the cumulative effect of initially applying the standard as an adjustment to the opening balance of retained earnings of the annual reporting period that includes the date of initial application (modified retrospective application). This guidance is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early application is not permitted. The Company is in the process of evaluating this guidance, though we do not expect it will materially impact our consolidated balance sheets, statements of income, comprehensive income or cash flows.

Investment_in_Affiliates_Table

Investment in Affiliates (Tables)	12 Months Ended
	Dec. 31, 2014
Investments in and Advances to Affiliates, Schedule of Investments [Abstract]
Investments in and Advances to Affiliates [Table Text Block]	At December 31, 2014 and 2013, the Company's investment in affiliates was comprised of the following (in thousands):
		2014		2013
	Investment in OCC	$	333	$	333
	Investment in Signal Trading	11,900		11,130
	Investment in IPXI	118		3,118
	Investment in CBSX	—		—
	Investment in Affiliates	$	12,351	$	14,581

Accounts_Payable_and_Accrued_L

Accounts Payable and Accrued Liabilites (Tables)	12 Months Ended
	Dec. 31, 2014
Accounts Payable and Accrued Liabilities, Current [Abstract]
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]	At December 31, 2014 and 2013, accounts payable and accrued liabilities consisted of the following (in thousands):
		2014		2013
	Compensation and benefit related liabilities	$	23,032	$	22,193
	Royalties	17,624		13,512
	Accounts payable	2,779		4,219
	Facilities	1,942		1,824
	Legal	1,355		1,602
	Market Linkage	1,183		1,157
	Purchase of unrestricted common stock (1)	1,159		1,937
	Other	9,492		6,514
	Total	$	58,566	$	52,958

Deferred_Revenue_Tables

Deferred Revenue (Tables)	12 Months Ended
	Dec. 31, 2014
Deferred Revenue [Abstract]
Deferred Revenue, by Arrangement, Disclosure [Table Text Block]	The following tables summarize the activity in deferred revenue for the years ended December 31, 2014 and 2013.
	(in thousands)	Balance at		Cash		Revenue			Balance at
		December 31,		Additions		Recognition			December 31,
		2013							2014
	Liquidity provider sliding scale	$	—	$	15,800	$	(15,800	)	$	—
	Other, net	1,100		11,429		(10,541		)	1,988
	Total deferred revenue	$	1,100	$	27,229	$	(26,341	)	$	1,988
	(in thousands)	Balance at		Cash		Revenue			Balance at
		December 31,		Additions		Recognition			December 31,
		2012							2013
	Liquidity provider sliding scale	$		$	29,232	$	(29,232	)	$	—
	Other, net	1,084		7,348		(7,332		)	1,100
	Total deferred revenue	$	1,084	$	36,580	$	(36,564	)	$	1,100

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	A reconciliation of the statutory federal income tax rate to the effective income tax rate for the years ended December 31, 2014, 2013 and 2012 is as follows:
		2014			2013			2012
	Statutory federal income tax rate	35	%		35	%		35	%
	State income tax rate, net of federal income tax effect	3.5			3.6			4.8
	Section 199 deductions	(1.7	)		(2.1	)		(7.5	)
	Other, net	1.9			1.5			2.8
	Effective income tax rate	38.7	%		38	%		35.1	%
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	The components of income tax expense for the years ended December 31, 2014, 2013 and 2012 are as follows (in thousands):
		2014				2013				2012
	Current:
	Federal	$	95,946			$	93,844			$	65,054
	State	24,327				20,958				20,597
	Total current	120,273				114,802				85,651
	Deferred:
	Federal	1,955				(4,636		)		406
	State	(2,245		)		(2,509		)		(901		)
	Total deferred	(290		)		(7,145		)		(495		)
	Total	$	119,983			$	107,657			$	85,156
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	At December 31, 2014 and 2013, the net deferred income tax liability is as follows (in thousands):
		2014				2013
	Deferred tax assets	$	26,962			$	25,144
	Deferred tax liabilities	(40,639		)		(38,889		)
	Net deferred income tax liability	$	(13,677	)		$	(13,745	)
	The tax effect of temporary differences giving rise to significant portions of deferred tax assets and liabilities at December 31, 2014 and 2013 are presented below (in thousands):
		2014				2013
	Deferred tax assets:
	Intangibles	$	44			$	50
	Accrued compensation and benefits	9,347				11,233
	Property, equipment and technology, net	596				697
	Investment in affiliates	6,325				6,158
	Other	10,650				7,006
	Total deferred tax assets	26,962				25,144
	Deferred tax liabilities:
	Property, equipment and technology, net	(37,851		)		(36,180		)
	Investment in affiliates	(1,696		)		(1,683		)
	Prepaid	(1,080		)		(1,027		)
	Other	(12		)		1
	Total deferred tax liabilities	(40,639		)		(38,889		)
	Net deferred tax liabilities	$	(13,677	)		$	(13,745	)
Summary of Income Tax Contingencies [Table Text Block]	A reconciliation of the beginning and ending uncertain tax positions, excluding interest and penalties, is as follows (in thousands):
		2014				2013				2012
	Balance as of January 1	$	26,745			$	19,493			$	12,185
	Gross increases on tax positions in prior period	2,828				549				3,401
	Gross decreases on tax positions in prior period	(1,053		)		(18		)		(833		)
	Gross increases on tax positions in current period	8,113				7,270				4,740
	Lapse of statute of limitations	(1,204		)		(549		)		—
	Balance as of December 31	$	35,429			$	26,745			$	19,493

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value, Measurement Inputs, Disclosure [Table Text Block]	The Company has included a tabular disclosure for financial assets that are measured at fair value on a recurring basis in the consolidated balance sheet as of December 31, 2014 and 2013. The Company holds no financial liabilities that are measured at fair value on a recurring basis.
	(amounts in thousands)	Level 1		Level 2		Level 3		Total
	Assets at fair value:
	Money market funds	$	135,000	—		—		$	135,000
	Total assets at fair value at December 31, 2014	$	135,000	$	—	$	—	$	135,000
	(amounts in thousands)	Level 1		Level 2		Level 3		Total
	Assets at fair value:
	Money market funds	$	207,000	—		—		$	207,000
	Total assets at fair value at December 31, 2013	$	207,000	$	—	$	—	$	207,000

Commitments_and_Contigencies_C

Commitments and Contigencies Commitments and Contigencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Future minimum payments for our operating leases and contractual obligations are as follows at December 31, 2014 (in thousands):
	Year	Operating		Contractual Obligations		Total
		Leases
	2015	$	2,811	18,157		$	20,968
	2016	2,628		20,463		23,091
	2017	696		23,057		23,753
	2018	—		20,070		20,070
	2019	—		20,084		20,084
	Total	$	6,135	$	101,831	$	107,966

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation [Abstract]
Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]	The activity in the Company's restricted stock, restricted stock units and performance shares for the year ended December 31, 2014 was as follows:
		Number of Shares		Weighted Average
		of Restricted		Grant-Date Fair
		Stock		Value
	Unvested restricted stock at January 1, 2014	708,221		$	33.41
	Granted	271,902		56.84
	Vested	(553,639	)	33.26
	Forfeited	(11,735	)	42.05
	Unvested restricted stock at December 31, 2014	414,749		$	46.44

Net_Income_per_Common_Share_Ta

Net Income per Common Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table reconciles net income applicable to common stockholders and the number of shares used to calculate the basic and diluted net income per common share for the for the years ended December 31, 2014, 2013 and 2012:
	(in thousands, except per share amounts)	2014			2013			2012
	Basic EPS Numerator:
	Net Income	$	189,714		$	175,999		$	157,395
	Less: Earnings allocated to participating securities	(1,322		)	(2,136		)	(2,141		)
	Net Income allocated to common stockholders	$	188,392		$	173,863		$	155,254
	Basic EPS Denominator:
	Weighted average shares outstanding	85,406			87,331			87,460
	Basic net income per common share	$	2.21		$	1.99		$	1.78
	Diluted EPS Numerator:
	Net Income	$	189,714		$	175,999		$	157,395
	Less: Earnings allocated to participating securities	(1,322		)	(2,136		)	(2,141		)
	Net Income allocated to common stockholders	$	188,392		$	173,863		$	155,254
	Diluted EPS Denominator:
	Weighted average shares outstanding	85,406			87,331			87,460
	Dilutive common shares issued under restricted stock program	—			—			—
	Diluted net income per common share	$	2.21		$	1.99		$	1.78

Quarterly_Data_Tables

Quarterly Data (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information [Table Text Block]	QUARTERLY DATA (unaudited)
	Year ended December 31, 2014 (in thousands)	First		Second		Third		Fourth		Year
		Quarter		Quarter		Quarter		Quarter
	Operating revenues	$	157,885	$	143,942	$	148,910	$	166,488	$	617,225
	Operating expenses	75,847		74,226		73,826		79,525		303,424
	Operating income	82,038		69,716		75,084		86,963		313,801
	Net income	$	49,024	$	42,981	$	48,366	$	49,342	$	189,714
	Net income allocated to common stockholders	$	48,528	$	42,598	$	48,146	$	49,119	$	188,392
	Diluted—net income per share to common stockholders	$	0.56	$	0.5	$	0.57	$	0.58	$	2.21
	Year ended December 31, 2013 (in thousands)	First		Second		Third		Fourth		Year
		Quarter		Quarter		Quarter		Quarter
	Operating revenues	$	142,705	$	150,772	$	136,743	$	141,830	$	572,050
	Operating expenses	73,275		75,414		68,316		69,231		286,236
	Operating income	69,430		75,358		68,427		72,599		285,814
	Net income	$	42,373	$	46,161	$	41,356	$	46,110	$	175,999
	Net income allocated to common stockholders	$	41,789	$	45,477	$	40,955	$	45,643	$	173,863
	Diluted—net income per share to common stockholders	$	0.48	$	0.52	$	0.47	$	0.52	$	1.99

Summary_of_Significant_Account2

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Advertising Expense	$4.30	$5.40	$5.30
Property, Plant and Equipment, Useful Life	5 years
Minimum [Member]
Concentration Risk, Customer	0.114
Property, Plant and Equipment, Estimated Useful Lives	P5Y
Property, Plant and Equipment, Useful Life	3 years
Maximum [Member]
Concentration Risk, Customer	0.459
Property, Plant and Equipment, Estimated Useful Lives	P40Y
Property, Plant and Equipment, Useful Life	5 years

Share_Repurchase_Program_Detai

Share Repurchase Program (Details) (USD $)	12 Months Ended			41 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Jul. 31, 2014	Dec. 11, 2013	Jul. 31, 2012	Aug. 31, 2011
Stock Repurchase Program, Authorized Amount					$100,000,000	$100,000,000	$100,000,000	$100,000,000
Treasury Stock, Shares, Acquired	3,215,246			7,855,070
Treasury Stock Acquired, Average Cost Per Share	$52.35			$39.51
Purchase of unrestricted common stock	-176,660,000	-51,426,000	-52,872,000
Stock Repurchase Program, Total Acquired	310,400,000			310,400,000
Treasury Stock
Purchase of unrestricted common stock	$168,300,000

Investment_in_Affiliates_Detai

Investment in Affiliates (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments in and Advances to Affiliates [Line Items]
Equity Gain Loss Investments	($1,217,000)	($1,976,000)	($1,695,000)
Investments in and Advances to Affiliates, Balance, Principal Amount	12,351,000	14,581,000
Cost-method Investments, Realized Losses, Excluding Other than Temporary Impairments	3,000,000
Cost Method Investment, Ownership Percentage, Other	5.00%	10.00%
Investment in OCC [Member]
Investments in and Advances to Affiliates [Line Items]
Investments in and Advances to Affiliates, Balance, Principal Amount	333,000	333,000
Cost Method Investment, Ownership Percentage	20.00%
Investment in IPXI [Member]
Investments in and Advances to Affiliates [Line Items]
Payments for (Proceeds from) Investments	0	612,000	1,250,000
Investments in and Advances to Affiliates, Balance, Principal Amount	118,000	3,118,000	2,500,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures		600,000
investment in CBSX [Member]
Investments in and Advances to Affiliates [Line Items]
Equity Method Investment, Ownership Percentage	49.96%
Investments in and Advances to Affiliates, Balance, Principal Amount	0	0
Investment in Signal Trading [Member]
Investments in and Advances to Affiliates [Line Items]
Equity Method Investment, Ownership Percentage	50.00%
Payments for (Proceeds from) Investments	1,987,000	1,920,000	1,661,000
Investments in and Advances to Affiliates, Balance, Principal Amount	$11,900,000	$11,130,000

Related_Parties_Details

Related Parties (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Transaction Fees	$437,764,000	$397,218,000	$357,146,000
Market data fees	30,447,000	24,911,000	24,360,000
OCC [Member]
Transaction Fees			544,300,000
Marketing fees	121,400,000	99,700,000	96,100,000
Accounts Receivable, Related Parties	59,800,000	48,600,000
OPTIONS PRICE REPORTING AUTHORITY [Member]
Accounts Receivable, Related Parties	4,200,000	3,900,000
Market data fees	15,100,000	12,900,000	15,000,000
CBOE STOCK EXCHANGE [Member]
Accounts Receivable, Related Parties		400,000
Costs and Expenses, Related Party	2,400,000	4,600,000	3,700,000
Options Regulatory Surveillance Authority [Member]
Accounts Receivable, Related Parties	1,200,000	1,200,000
Costs and Expenses, Related Party	2,700,000	2,300,000	2,100,000
CHICAGO BOARD OPTIONS EXCHANGE [Member] | OCC [Member]
Transaction Fees	687,500,000	610,300,000
CBOE FUTURES EXCHANGE [Member] | OCC [Member]
Transaction Fees	$84,700,000	$65,700,000

Accounts_Payable_and_Accrued_L1

Accounts Payable and Accrued Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts Payable and Accrued Liabilities, Current [Abstract]
Compensation and benefit related liabilities	$23,032	$22,193
Royalties	17,624	13,512
Accounts payable	2,779	4,219
Facilities	1,942	1,824
Legal	1,355	1,602
Market Linkage	1,183	1,157
Purchase of unrestricted common stock (1)	1,159	1,937
Other	9,492	6,514
Accounts Payable and Accrued Liabilities, Current	$58,566	$52,958

Marketing_Fee_Marketing_Fee_De

Marketing Fee Marketing Fee (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Marketing Fee [Abstract]
Marketing Fee Receivable Current	$10,697	$8,869
Marketing Fee Payable Current	$11,236	$9,442

Deferred_Revenue_Details

Deferred Revenue (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Revenue Arrangement [Line Items]
Increase (Decrease) in Deferred Revenue	$1,229,000	($75,000)	$773,000
Deferred Revenue	1,988,000	1,100,000	1,084,000
Deferred Revenue, Period Increase (Decrease)	27,229,000	36,580,000
Liquidity Provider Cash Received [Member]
Deferred Revenue Arrangement [Line Items]
Increase (Decrease) in Deferred Revenue and Customer Advances and Deposits	15,800,000
Increase (Decrease) in Deferred Revenue and Customer Advances and Deposits		29,232,000
Liquidity Provider Revenue Recognized [Member]
Deferred Revenue Arrangement [Line Items]
Increase (Decrease) in Deferred Revenue and Customer Advances and Deposits	-15,800,000
Increase (Decrease) in Deferred Revenue and Customer Advances and Deposits		-29,232,000
Other Deferred Revenue Recognized [Member]
Deferred Revenue Arrangement [Line Items]
Increase (Decrease) in Deferred Revenue	-10,540,961	-7,332,000
Other Deferred Revenue Cash Received [Member]
Deferred Revenue Arrangement [Line Items]
Increase (Decrease) in Deferred Revenue	11,429,419	7,347,709
Other Deferred Revenue [Member]
Deferred Revenue Arrangement [Line Items]
Deferred Revenue	1,988,000	1,100,000	1,084,000
Other Deferred Revenue Recognized [Member]
Deferred Revenue Arrangement [Line Items]
Increase (Decrease) in Deferred Revenue	($26,341,000)	($36,564,000)

Employee_Benefits_Details

Employee Benefits (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
Defined Benefit Plan, Contributions by Employer	$4.50	$4	$3.90
Pension and Other Postretirement Benefit Contributions	$1.50	$1.60	$1.40

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate		35.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, State and Local Income Taxes		3.50%	3.60%	4.80%
Effective Income Tax Rate Reconciliation, Deductions, Qualified Production Activities		-1.70%	-2.10%	-7.50%
Effective Income Tax Rate Reconciliation, Other Adjustments		1.90%	1.50%	2.80%
Effective Income Tax Rate, Continuing Operations		38.70%	38.00%	35.10%
Income Tax Reconciliation, Deductions, Qualified Production Activities				$12,900,000
Current Federal Tax Expense (Benefit)		95,946,000	93,844,000	65,054,000
Current State and Local Tax Expense (Benefit)		24,327,000	20,958,000	20,597,000
Current Income Tax Expense (Benefit)		120,273,000	114,802,000	85,651,000
Deferred Federal Income Tax Expense (Benefit)		1,955,000	-4,636,000	406,000
Deferred State and Local Income Tax Expense (Benefit)		-2,245,000	-2,509,000	-901,000
Deferred Income Tax Expense (Benefit)		-290,000	-7,145,000	-495,000
Income Tax Expense (Benefit)		119,983,000	107,657,000	85,156,000
Deferred Tax Assets, Net	26,962,000	26,962,000	25,144,000
Deferred Tax Liabilities, Gross	-40,639,000	-40,639,000	-38,889,000
Deferred Tax Liabilities, Net, Noncurrent	-13,677,000	-13,677,000	-13,745,000
Deferred Tax Assets, Goodwill and Intangible Assets	44,000	44,000	50,000
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	9,347,000	9,347,000	11,233,000
Deferred Tax Assets, Depreciation	596,000	596,000	697,000
Deferred Tax Assets, Investment in Noncontrolled Affiliaties	6,325,000	6,325,000	6,158,000
Deferred Tax Assets, Other	10,650,000	10,650,000	7,006,000
Deferred Tax Liabilities, Property, Plant and Equipment	-37,851,000	-37,851,000	-36,180,000
Deferred Tax Liabilities, Investment in Noncontrolled Affiliates	-1,696,000	-1,696,000	-1,683,000
Deferred Tax Liabilities, Prepaid Expenses	-1,080,000	-1,080,000	-1,027,000
Deferred Tax Liabilities, Other	-12,000	-12,000	1,000
Unrecognized Tax Benefits	35,429,000	35,429,000	26,745,000	19,493,000	12,185,000
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions		2,828,000	549,000	3,401,000
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions		-1,053,000	-18,000	-833,000
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions		8,113,000	7,270,000	4,740,000
Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations	15,900,000	-1,204,000	-549,000	0
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	35,400,000	35,400,000	26,700,000	19,500,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense		2,100,000	1,800,000	600,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$5,300,000	$5,300,000	$3,200,000	$1,400,000

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Money Market Funds, at Carrying Value	$135,000,000	$207,000,000
Assets, Fair Value Disclosure	135,000,000	207,000,000
Cost Method Investment, Ownership Percentage, Other	5.00%	10.00%
Investments in and Advances to Affiliates, Balance, Principal Amount	12,351,000	14,581,000
Cost-method Investments, Realized Losses, Excluding Other than Temporary Impairments	3,000,000
Investment in IPXI [Member]
Investments in and Advances to Affiliates, Balance, Principal Amount	118,000	3,118,000	2,500,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures		$600,000

Commitments_and_Contigencies_D

Commitments and Contigencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Leases, Rent Expense	$3,800,000	$3,000,000	$3,500,000
Operating Leases, Future Minimum Payments Due, Current	2,811,000
Purchase Obligation	18,157,000
Total Operating Leases and Advertising Obligations, Current	20,968,000
Operating Leases, Future Minimum Payments, Due in Two Years	2,628,000
Purchase Obligation, Due in Second Year	20,463,000
Total Operating Leases and Advertising Obligations, due in two years	23,091,000
Operating Leases, Future Minimum Payments, Due in Three Years	696,000
Purchase Obligation, Due in Third Year	23,057,000
Total Operating Leases and Advertising Obligations, due within three years	23,753,000
Operating Leases, Future Minimum Payments, Due in Four Years	0
Purchase Obligation, Due in Fourth Year	20,070,000
Total Operating Leases and Advertising Obligations, due within four years	20,070,000
Operating Leases, Future Minimum Payments, Due in Five Years	0
Purchase Obligation, Due after Fifth Year	20,084,000
Total Operating Leases and Advertising Obligations, due within five years	20,084,000
Operating Leases, Future Minimum Payments Due	6,135,000
Purchase Obligation	101,831,000
Operating Leases and Advertising Obligations, future amounts due	$107,966,000
Minimum [Member]
Lessee Leasing Arrangements, Operating Leases, Term of Contract	8 months
Maximum [Member]
Lessee Leasing Arrangements, Operating Leases, Term of Contract	31 months

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	0 Months Ended			3 Months Ended		12 Months Ended
	Feb. 19, 2015	22-May-14	Feb. 19, 2014	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized						4,248,497
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$61.96	$49.36	$55.35			$56.84
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage				50.00%
Stock-based compensation						$15,577,000	$20,823,000	$12,348,000
Share-based Compensation Arrangement by Share-based Payment Award Accelerated Compensation Cost				800,000	3,200,000	2,500,000	4,000,000	300,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number						414,749	708,221
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value						$46.44	$33.41
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures	205,030		206,192			271,902
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate						0.69%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate						24.80%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period						-553,639
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value						$33.26
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period						-11,735
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price						$42.05
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized						12,300,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition						1 year 4 months 24 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Total Fair Value				$2,500,000		$18,415,000
Restricted Stock [Member]
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures			45,168
Restricted Stock Units (RSUs) [Member]
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures			161,024
BOD [Member]
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		18,240
CEO COO [Member]
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures			47,470
Minimum [Member]
Share Based Conpensation,Forfeiture Rate						2.00%
Maximum [Member]
Share Based Conpensation,Forfeiture Rate						5.00%
EarningsPerShare [Member] | CEO COO [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value			$55.35
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures			23,735
TotalShareholderReturn [Member] | CEO COO [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value			$77
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures			23,735

Net_Income_per_Common_Share_De

Net Income per Common Share (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Net Income (Loss) Attributable to Parent									$189,714	$175,999	$157,395
Net Income allocated to participating securities									1,322	2,136	2,141
Net Income (Loss) Available to Common Stockholders, Basic									188,392	173,863	155,254
Weighted Average Number of Shares Outstanding, Basic									85,406	87,331	87,460
Basic (in dollars per share)									$2.21	$1.99	$1.78
Net Income (Loss) Available to Common Stockholders, Diluted	$49,119	$48,146	$42,598	$48,528	$45,643	$40,955	$45,477	$41,789	$188,392	$173,863	$155,254
Weighted Average Number of Shares Outstanding, Diluted									85,406	87,331	87,460
Diluted—net income per share to common stockholders	$0.58	$0.57	$0.50	$0.56	$0.52	$0.47	$0.52	$0.48	$2.21	$1.99	$1.78

Quarterly_Data_Quarterly_Data_

Quarterly Data Quarterly Data (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Operating revenues	$166,488,000	$148,910,000	$143,942,000	$157,885,000	$141,830,000	$136,743,000	$150,772,000	$142,705,000	$617,225,000	$572,050,000	$512,338,000
Operating expenses	79,525,000	73,826,000	74,226,000	75,847,000	69,231,000	68,316,000	75,414,000	73,275,000	303,424,000	286,236,000	268,241,000
Operating income	86,963,000	75,084,000	69,716,000	82,038,000	72,599,000	68,427,000	75,358,000	69,430,000	313,801,000	285,814,000	244,097,000
Net income	49,342,000	48,366,000	42,981,000	49,024,000	46,110,000	41,356,000	46,161,000	42,373,000	189,714,000	175,999,000	157,395,000
Net income allocated to common stockholders	49,119,000	48,146,000	42,598,000	48,528,000	45,643,000	40,955,000	45,477,000	41,789,000	188,392,000	173,863,000	155,254,000
Diluted—net income per share to common stockholders	$0.58	$0.57	$0.50	$0.56	$0.52	$0.47	$0.52	$0.48	$2.21	$1.99	$1.78
Share-based Compensation Arrangement by Share-based Payment Award Accelerated Compensation Cost							800,000	3,200,000	2,500,000	4,000,000	300,000
Loss Contingency Accrual, at Carrying Value							1,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Total Fair Value							2,500,000		18,415,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage							50.00%
Income Tax Reconciliation, Deductions, Qualified Production Activities											12,900,000
Severance Costs	1,900,000
Cost-method Investments, Realized Losses, Excluding Other than Temporary Impairments									$3,000,000

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	0 Months Ended			12 Months Ended
	Feb. 19, 2015	22-May-14	Feb. 19, 2014	Dec. 31, 2014	Feb. 04, 2015
Declared Dividends Per Share					$0.21
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	205,030		206,192	271,902
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$61.96	$49.36	$55.35	$56.84