Cboe Global Markets (CBOE) 10-Q 2 Aug 16 2016 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	6 Months Ended
	Jun. 30, 2016	Jul. 31, 2016
Entity [Abstract]
Entity Registrant Name	CBOE Holdings, Inc.
Entity Central Index Key	1,374,310
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		81,285,307
Entity Current Reporting Status	Yes

Condensed Consolidated Statemen

Condensed Consolidated Statement of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Operating Revenues:
Transaction fees	$ 117,934	$ 101,617	$ 235,937	$ 200,340
Access fees	13,179	13,371	26,429	27,057
Exchange services and other fees	11,359	9,736	22,750	19,464
Market data fees	8,172	7,557	16,141	15,569
Regulatory fees	9,219	8,746	18,319	17,128
Other revenue	3,466	7,698	6,083	12,006
Total Operating Revenues	163,329	148,725	325,659	291,564
Operating Expenses:
Compensation and benefits	28,530	24,136	55,636	49,574
Depreciation and amortization	12,260	11,275	24,111	21,677
Technology support services	5,658	4,813	11,336	10,138
Professional fees and outside services	14,745	12,594	28,376	24,544
Royalty fees	19,336	16,755	38,450	30,905
Order routing	(83)	627	21	1,414
Travel and promotional expenses	2,492	2,526	5,006	5,027
Facilities costs	1,418	1,293	2,946	2,677
Other expenses	1,006	1,336	2,328	2,684
Total Operating Expenses	85,362	75,355	168,210	148,640
Operating Income	77,967	73,370	157,449	142,924
Other Income/(Expense):
Investment income	5,657	59	6,364	110
Net income/(loss) from investments	218	202	524	(125)
Interest and Debt Expense	(28)	0	(55)	0
Total Other Income/(Expense)	5,847	261	6,833	(15)
Income Before Income Taxes	83,814	73,631	164,282	142,909
Income tax provision	32,883	28,786	64,175	55,804
Net Income	50,931	44,845	100,107	87,105
Net loss attributable to noncontrolling interests	299	0	523	0
Net Income Excluding Noncontrolling Interests	51,230	44,845	100,630	87,105
Change in redemption value of noncontrolling interest	(299)	0	(523)	0
Net income allocated to participating securities	212	199	414	379
Net Income allocated to common stockholders	$ 50,719	$ 44,646	$ 99,693	$ 86,726
Net Income Per Share Allocated to Common Stockholders:
Basic	$ 0.62	$ 0.54	$ 1.22	$ 1.04
Diluted	$ 0.62	$ 0.54	$ 1.22	$ 1.04
Diluted EPS Denominator:
Basic	81,343	83,290	81,580	83,621
Diluted	81,343	83,290	81,580	83,621

Condensed Consolidated Stateme3

Condensed Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Condensed Consolidated Statement of Comprehnsive Income [Abstract]
Net Income	$ 50,931	$ 44,845	$ 100,107	$ 87,105
Comprehensive Income (Loss) - net of tax:
Post-retirement benefit obligation	11	18	40	(163)
Comprehensive Income	50,942	44,863	100,147	86,942
Comprehensive loss attributable to noncontrolling interests	299	0	523	0
Comprehensive Income Excluding Noncontrolling Interests	51,241	44,863	100,670	86,942
Change in redemption value of noncontrolling interests	(299)	0	(523)	0
Net income allocated to participating securities	212	199	414	379
Comprehensive Income Allocated to Common Stockholders	$ 50,730	$ 44,664	$ 99,733	$ 86,563

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 52,193	$ 102,253
Accounts receivable—net allowances of 2016 - $87 and 2015 - $150	71,129	62,535
Marketing fee receivable	7,052	5,682
Income taxes receivable	32,489	27,901
Other prepaid expenses	10,577	5,122
Other current assets	432	625
Total Current Assets	173,872	204,118
Investments	72,698	48,430
Land	4,914	4,914
Property and Equipment:
Construction in progress	4,083	885
Building	71,158	70,531
Furniture and equipment	152,384	144,597
Less accumulated depreciation and amortization	(166,495)	(155,653)
Total Property and Equipment—Net	61,130	60,360
Goodwill	26,468	7,655
Other Assets:
Intangible assets (less accumulated amortization—2016 - $1,038 and 2015 - $182)	9,522	2,378
Software development work in progress	19,876	13,836
Data processing software and other assets (less accumulated amortization—2016 - $173,108 and 2015 - $164,152)	38,164	43,097
Total Other Assets—Net	67,562	59,311
Total	406,644	384,788
Current Liabilities:
Accounts payable and accrued liabilities	54,721	60,104
Marketing fee payable	7,532	6,141
Deferred revenue and other liabilities	10,876	4,019
Post-retirement benefit obligation - current	54	100
Contingent consideration - current	3,434	2,000
Total Current Liabilities	15	1,633
Total Current Liabilities	76,632	73,997
Long-term Liabilities:
Post-retirement benefit obligation - long-term	1,902	1,896
Contingent consideration - long term	0	1,379
Income tax liability	42,175	39,679
Other long-term liabilities	2,605	2,883
Deferred income taxes	4,967	5,309
Total Long-term Liabilities	51,649	51,146
Commitments and Contingencies
Total Liabilities	128,281	125,143
Redeemable Noncontrolling Interests	12,600	0
Stockholders’ Equity:
Preferred stock, $0.01 par value: 20,000,000 shares authorized, no shares issued and outstanding at June 30, 2016 or December 31, 2015	0	0
Additional paid-in-capital	131,851	123,577
Retained earnings	666,016	603,597
Treasury stock at cost – 11,664,758 shares at June 30, 2016 and 10,650,254 shares at December 31, 2015	(532,249)	(467,632)
Accumulated other comprehensive loss	(784)	(824)
Total Stockholders’ Equity	265,763	259,645
Total	406,644	384,788
Unrestricted Common Stock
Stockholders’ Equity:
Common stock, $0.01 par value: 325,000,000 shares authorized; 92,950,065 issued and 81,285,307 outstanding at June 30, 2016; 92,738,803 issued and 82,088,549 outstanding at December 31, 2015	$ 929	$ 927

Condensed Consolidated Balance5

Condensed Consolidated Balance Sheets Parenthetical - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Allowance for Doubtful Accounts Receivable, Current	$ 87,000	$ 150,000
Capitalized Computer Software, Accumulated Amortization	173,108,000	164,152,000
Less accumulated amortization	$ 1,038,000	$ 182,000
Preferred Stock, Par or Stated Value 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
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	325,000,000	325,000,000
Common Stock, Shares, Issued	92,950,065	92,738,803
Common Stock, Shares, Outstanding	81,285,307	82,088,549
Treasury Stock, Shares	11,664,758	10,650,254

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Stockholders’ Equity - 6 months ended Jun. 30, 2016 - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss	Redeemable Noncontrolling Interests
Balance—January 1, 2016 at Dec. 31, 2015	$ 259,645	$ 0	$ 927	$ 123,577	$ 603,597	$ (467,632)	$ (824)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends on common stock	(37,688)				(37,688)
Stock-based compensation	7,105			7,105
Excess tax benefits from stock-based compensation plan	1,171			1,171
Issuance of vested restricted stock granted to employees	0		2	(2)
Purchase of common stock	(64,617)					(64,617)
Net Income excluding noncontrolling interests	100,630				100,630
Post-retirement benefit obligation adjustment—net of tax expense $27	40						40
Balance—June 30, 2016 at Jun. 30, 2016	265,763	$ 0	$ 929	$ 131,851	666,016	$ (532,249)	$ (784)
Redeemable Noncontrolling Interests, beginning value at Dec. 31, 2015	0
Increase (Decrease) in Temporary Equity [Roll Forward]
Increase due to acquiring majority of outstanding equity of Vest	12,600							$ 12,600
Net loss attributable to redeemable noncontrolling interest								(523)
Redemption value adjustment					$ (523)			$ 523
Redeemable Noncontrolling Interests, ending value at Jun. 30, 2016	$ 12,600

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Stockholders’ Equity Parenthetical $ in Millions	6 Months Ended
	Jun. 30, 2016USD ($)
Statement of Stockholders' Equity [Abstract]
Post-retirement benefit obligation adjustment, tax expense (benefit)	$ 27

Condensed Consolidated Stateme8

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash Flows from Operating Activities:
Net Income	$ 100,107	$ 87,105
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	24,111	21,677
Other amortization	40	36
Provision for deferred income taxes	(369)	536
Stock-based compensation	7,105	5,801
Loss on disposition of property	2	392
Equity (gain) in investment	(524)	(239)
Impairment of investment and other assets	0	118
Change in assets and liabilities:
Accounts receivable	(8,594)	(5,246)
Marketing fee receivable	(1,370)	3,051
Income taxes receivable	(4,588)	(1,713)
Prepaid expenses	(5,430)	(5,837)
Other current assets	195	695
Accounts payable and accrued expenses	(4,617)	(7,636)
Marketing fee payable	1,391	(2,882)
Deferred revenue and other liabilities	6,579	8,183
Post-retirement benefit obligations	(13)	(10)
Income tax liability	2,496	2,449
Income tax payable	(1,618)	(655)
Net Cash Flows provided by Operating Activities	114,903	105,825
Cash Flows from Investing Activities:
Capital and other assets expenditures	(25,430)	(17,636)
Acquisition of a majority interest in a business, net of cash received	(14,257)	0
Investments	(23,744)	(30,935)
Other	(398)	246
Net Cash Flows used in Investing Activities	(63,829)	(48,325)
Cash Flows from Financing Activities:
Payment of quarterly dividends	(37,688)	(35,288)
Excess tax benefit from stock-based compensation	1,171	1,246
Purchase of common stock from employees	(4,119)	(3,119)
Purchase of common stock under announced program	(60,498)	(78,632)
Net Cash Flows used in Financing Activities	(101,134)	(115,793)
Net Decrease in Cash and Cash Equivalents	(50,060)	(58,293)
Cash and Cash Equivalents at Beginning of Period	102,253	147,927
Cash and Cash Equivalents at End of Period	52,193	89,634
Supplemental Disclosure of Cash Flow Information
Cash paid for income taxes	$ 67,200	$ 53,860

Description of Business

Description of Business	6 Months Ended
	Jun. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description Of Business	DESCRIPTION OF BUSINESS CBOE Holdings, Inc. is the holding company for Chicago Board Options Exchange, Incorporated, CBOE Futures Exchange, LLC, C2 Options Exchange, Incorporated and other subsidiaries, including our majority ownership in Vest Financial Group Inc. ("Vest"). The Company's principal business is operating markets that offer for trading options on various market indexes (index options), mostly on an exclusive basis, 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). The Company operates CBOE, CFE and C2 as stand-alone exchanges, but reports the results of its operations in a single reporting segment. CBOE is our primary options market and offers trading in listed options through a single system that integrates electronic trading and traditional open outcry trading on our trading floor in Chicago. This integration of electronic trading and traditional open outcry trading into a single exchange is known as our Hybrid trading model. CFE, our all-electronic futures exchange, offers trading of futures on the VIX Index and other products. C2 is our all-electronic exchange that also offers trading for listed options, and may operate with a different market model and fee structure than CBOE. All of our exchanges operate on our proprietary technology platform known as CBOE Command.

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2016
Accounting Policies [Abstract]
Basis of Presentation	BASIS OF PRESENTATION These interim unaudited condensed consolidated financial statements have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 . The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities, valuation of redeemable noncontrolling interests 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. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation of financial position, results of operations and cash flows at the dates and for the periods presented have been included. The results of operations for interim periods are not necessarily indicative of the results of operations for the full year. Recent Accounting Pronouncements 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 FASB deferred the effective date by one year to December 15, 2017 for annual reporting periods beginning after that date. Early adoption of the standard is permitted, but not before the original effective date of December 15, 2016. 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. In September 2015, the FASB issued ASU 2015-16, Business Combinations . This standard simplifies the accounting for adjustments made to provisional amounts recognized in a business combination. First, it requires that the acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amount is determined. The acquirer also should record, in the same period's financial statements, the effect on earnings of changes in depreciation, amortization, or other income effects, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date. The amendments should be applied prospectively to adjustments to provisional amounts that are identified after December 15, 2015 and that are within the measurement period. Upon transition, an entity would be required to disclose the nature of, and reason for, the change in accounting principle. An entity would provide that disclosure in the first annual period of adoption and in the interim periods within the first annual period. The Company has adopted this guidance, though we do not expect it will materially impact our consolidated balance sheets, statements of income, comprehensive income or cash flows. In February 2016, the FASB issued ASU 2016-02, Leases . This update requires a lessee to recognize on the balance sheet a liability to make lease payments and a corresponding right-of-use asset. The guidance also requires certain qualitative and quantitative disclosures about the amount, timing and uncertainty of cash flows arising from leases. This update is effective for annual and interim periods beginning after December 15, 2018. Early adoption is 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. In March 2016, the FASB issued ASU 2016-09, Compensation — Stock Compensation . This standard simplifies several aspects of the accounting for stock-based payment transactions, including the recognition of excess tax benefits and deficiencies, the classification of those excess tax benefits on the statement of cash flows, an accounting policy election for forfeitures, the amount an employer can withhold to cover income taxes and still qualify for equity classification and the classification of those taxes paid on the statement of cash flows. This update is effective for annual and interim periods beginning after December 15, 2016 and can be applied either prospectively, retrospectively or using a modified retrospective transition method, depending on the area covered in this update. Early adoption is 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.

Acquisitions- Goodwill and Inta

Acquisitions- Goodwill and Intangible Assets (Notes)	6 Months Ended
	Jun. 30, 2016
Business Combinations [Abstract]
Acquisitions- Goodwill and Intangible Assets	3. ACQUISITIONS - GOODWILL AND INTANGIBLE ASSETS Vest Financial Group Inc. In January 2016, the Company, through its subsidiary CBOE Vest, LLC, acquired a majority of the outstanding equity of Vest, an asset management firm that provides options-based investments through structured protective strategies and innovative technology solutions which allows for enhanced integration of our proprietary products, strategy indexes and options expertise. The purchase price consisted of $18.9 million in cash, reflecting payments of $14.9 million to former stockholders and $4.0 million to Vest for newly issued shares, and represented an ownership interest of 60% resulting in the consolidation of the operations. The purchase price was allocated on a preliminary basis, subject to final allocation, to the assets acquired based on their fair values at the acquisition date. (amounts in thousands) Purchase Price $ 18,900 Fair Value of Assets Acquired: Cash $ 4,700 Intangible assets 8,000 Goodwill 18,800 Total Assets Acquired $ 31,500 Redeemable noncontrolling interests 12,600 Net Assets Acquired $ 18,900 The remaining 40% noncontrolling interest is held by the remaining Vest stockholders. The remaining Vest stockholders have a put option that can be exercised to Vest and Vest has a call option that can be exercised to the remaining stockholders. The put and call options can be exercised after five years though they could be accelerated by certain employment-related actions. The combination of the noncontrolling interest and a redemption feature resulted in a redeemable noncontrolling interest, which is classified outside of permanent equity on the condensed consolidated balance sheet. In addition to the tangible and intangible assets, goodwill totaling $18.8 million was recorded in connection with the acquisition. Goodwill was calculated as the excess of the consideration transferred over the net assets recognized and represents potential future economic benefits arising from other assets acquired that could not be individually identified and separately recognized. The goodwill is not expected to be deductible for tax purposes. Pro forma financial information has not been provided as the Vest acquisition is not material to our consolidated balance sheets, statements of income, comprehensive income or cash flows and did not meet the conditions of a significant subsidiary under Rule 1-02 of Regulation S-X. Vest - Intangible Assets Intangible assets totaling $8.0 million were recorded in 2016 in connection with the acquisition of Vest and include: customer relationships, trade names, and technology. Intangible assets and related accumulated amortization consisted of the following as of June 30, 2016 (in thousands): As of June 30, 2016 Estimated Useful Lives Customer relationships $ 3,000 9 years Trade names 1,000 7 years Technology 4,000 5 years Total Intangible Assets Acquired 8,000 Less accumulated amortization 638 Total Intangibles, net $ 7,362 For the three and six months ended June 30, 2016 , amortization of Vest intangible assets was $0.3 million and $0.6 million , respectively. The remaining weighted average useful lives of the intangible assets is 5.9 years as of June 30, 2016 . The future expected amortization expense from the intangible assets related to the Vest acquisition as of June 30, 2016 is as follows (in thousands): Year Amortization expense 2016 (1) $ 638 2017 1,276 2018 1,276 2019 1,276 2020 1,276 Total $ 5,742 (1) Includes expected amortization for the remaining six months of 2016. Livevol, Inc. On August 7, 2015, the Company acquired the market data services and trading analytics platforms of Livevol, Inc. ("Livevol"), which included Livevol Core, Livevol Pro and Livevol X trading analytics platforms, as well as Livevol Enterprise and other market data solutions products. The purchase price consisted of $7.0 million cash, including $4.0 million paid to existing Livevol debt holders and $3.0 million to Livevol owners, upon closing plus contingent consideration based on achievement of certain performance targets, measured at nine and eighteen months from the acquisition date of August 7, 2015. The purchase price was allocated on a preliminary basis, subject to final allocation, to the assets acquired based on their fair values at the acquisition date. The acquisition included tangible and intangible assets totaling $0.1 million and $2.6 million , respectively. The tangible assets primarily reflect computer hardware and intangible assets include: customer relationships, trade names, existing technology, non-compete agreements and a leasehold right. In addition to the assets, goodwill totaling $7.7 million was recorded in connection with the acquisition. Goodwill was calculated as the excess of the consideration transferred over the net assets recognized and represents potential future economic benefits arising from other assets acquired that could not be individually identified and separately recognized. The goodwill is expected to be fully deductible for tax purposes. As of June 30, 2016 , the company recorded contingent consideration of $3.4 million , which is based on management's estimate of the performance target achievement by Livevol. If Livevol were to exceed management's estimates it could result in an additional payment in excess of the recorded contingent consideration. Livevol - Intangible Assets Intangible assets totaling $2.6 million were recorded in 2015 in connection with the acquisition of Livevol include: customer relationships, trade names, existing technology, non-compete agreements and leasehold rights. Intangible assets and related accumulated amortization consisted of the following as of June 30, 2016 (in thousands): As of June 30, 2016 Estimated Useful Lives Customer relationships $ 910 13 years Trade names 370 10 years Technology 1,130 2-5 years Other 150 1-4 years Total 2,560 Less accumulated amortization 400 Total Intangibles, net $ 2,160 For the three and six months ended June 30, 2016 , amortization of Livevol intangible assets was $0.1 million and $0.2 million , respectively. The remaining weighted average useful lives of the intangible assets is 7.8 years as of June 30, 2016 . The future expected amortization expense from the intangible assets related to the Livevol acquisition as of June 30, 2016 is as follows (in thousands): Year Amortization expense 2016 (1) $ 217 2017 379 2018 349 2019 309 2020 206 Total $ 1,460 (1) Includes expected amortization for the remaining six months of 2016.

Redeemable Noncontrolling Inter

Redeemable Noncontrolling Interest	6 Months Ended
	Jun. 30, 2016
Equity [Abstract]
Redeemable Noncontrolling Interest	NOTE 4 — REDEEMABLE NONCONTROLLING INTEREST Redeemable noncontrolling interests are reported on the condensed consolidated balance sheets in mezzanine equity in "Redeemable Noncontrolling Interests." We recognize changes to the redemption value of redeemable noncontrolling interests as they occur and adjust the carrying value to equal the redemption value at the end of each reporting period. The resulting increases or decreases in the estimated redemption amount are affected by corresponding charges or credits against retained earnings, or in the absence of retained earnings, additional paid in capital. The redemption amounts have been estimated based on the fair value of the majority-owned subsidiary, determined based on a weighting of the discounted cash flow and other economic factors. For the six months ended June 30, 2016 , the following reflects changes in our redeemable noncontrolling interests (in thousands): Redeemable Noncontrolling Interest Balance as of January 1, 2016 $ — Increase due to acquiring majority of outstanding equity of Vest 12,600 Net loss attributable to redeemable noncontrolling interest (523 ) Redemption value adjustment 523 Balance as of June 30, 2016 $ 12,600

Net Income per Common Share

Net Income per Common Share	6 Months Ended
	Jun. 30, 2016
Earnings Per Share [Abstract]
New Income per Common Share	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. Additionally, in accordance with accounting guidance, the change in the redemption value for the noncontrolling interest in Vest reduces net income allocated to common shareholders. The following table reconciles net income allocated to common stockholders and the number of shares used to calculate the basic and diluted net income per common share for the three and six months ended June 30, 2016 and 2015 : Three Months Ended June 30, Six Months Ended June 30, (in thousands, except per share amounts) 2016 2015 2016 2015 Basic EPS Numerator: Net Income $ 50,931 $ 44,845 $ 100,107 $ 87,105 Loss attributable to noncontrolling interests 299 — 523 — Net income excluding noncontrolling interests 51,230 44,845 100,630 87,105 Change in redemption value of noncontrolling interest (299 ) — (523 ) — Earnings allocated to participating securities (212 ) (199 ) (414 ) (379 ) Net Income allocated to common stockholders $ 50,719 $ 44,646 $ 99,693 $ 86,726 Basic EPS Denominator: Weighted average shares outstanding 81,343 83,290 81,580 83,621 Basic Net Income Per Common Share $ 0.62 $ 0.54 $ 1.22 $ 1.04 Diluted EPS Numerator: Net Income $ 50,931 $ 44,845 $ 100,107 $ 87,105 Loss attributable to noncontrolling interests 299 — 523 — Net income excluding noncontrolling interests 51,230 44,845 100,630 87,105 Change in redemption value of noncontrolling interest (299 ) — (523 ) — Earnings allocated to participating securities (212 ) (199 ) (414 ) (379 ) Net Income allocated to common stockholders $ 50,719 $ 44,646 $ 99,693 $ 86,726 Diluted EPS Denominator: Weighted average shares outstanding 81,343 83,290 81,580 83,621 Dilutive common shares issued under stock program — — — — Diluted Net Income Per Common Share $ 0.62 $ 0.54 $ 1.22 $ 1.04 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.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2016
Share-based Compensation [Abstract]
Stock-Based Compensation	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. On February 19, 2016 , the Company granted 170,081 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 $61.80 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 RSUs will be forfeited if the officer or employee leaves the Company prior to the applicable vesting date, except in limited circumstances. The RSUs have no voting rights but entitle the holder to receive dividend equivalents. In addition, on February 19, 2016 , the Company granted 49,238 RSUs contingent on the achievement of performance conditions, including 24,619 RSUs, at a fair value of $61.80 per RSU, related to earnings per share during the performance period and 24,619 RSUs, at a fair value of $83.00 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 ( 0.90% ), three-year volatility ( 21.1% ) and three-year correlation with S&P 500 Index ( 0.41 ). 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 RSUs contingent on the achievement of performance is three years. For each of the performance awards, the RSUs will be settled in shares of our common stock following vesting of the RSU assuming that the participant has been continuously employed during the vesting period, subject to acceleration in the event of a change in control of the Company or in the event of a participant’s earlier death or disability. Participants have no voting rights with respect to RSUs 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 19, 2016 , the Company granted 20,553 shares of stock, at a fair value of $63.29 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 stock will be forfeited if the director leaves the company prior to the applicable vesting date. For the three and six months ended June 30, 2016 and 2015 , the Company recognized $3.7 million and $3.1 million and $7.1 million and $5.8 million in stock-based compensation expense, respectively. The three and six months ended June 30, 2016 included $0.3 million and $0.5 million of accelerated stock-based compensation expense, respectively, for certain officers and employees as a result of attaining certain age and service based requirements in our long-term incentive plan and award agreements. Stock-based compensation expense is included in compensation and benefits in the condensed consolidated statements of income. As of June 30, 2016 , the Company had unrecognized stock-based compensation of $25.3 million . The remaining unrecognized stock-based compensation is expected to be recognized over a weighted average period of 26.8 months. The activity in the Company’s restricted stock and restricted stock units for the six months ended June 30, 2016 was as follows: Number of Shares Weighted Average Unvested at January 1, 2016 456,570 $ 55.70 Granted 241,681 64.10 Vested (211,235 ) 48.14 Forfeited (4,133 ) 59.67 Unvested at June 30, 2016 482,883 $ 63.34

Investments

Investments	6 Months Ended
	Jun. 30, 2016
Investments in and Advances to Affiliates, Schedule of Investments [Abstract]
Investments in Affiliates	INVESTMENTS At June 30, 2016 and December 31, 2015 , the Company's investments were comprised of the following (in thousands): June 30, December 31, Equity Method Investment in Signal Trading Systems, LLC 12,183 12,185 Investment in CBOE Stock Exchange, LLC — — Total equity method investments 12,183 12,185 Cost Method Investment in OCC 30,333 30,333 Other cost method investments 30,182 5,912 Total cost method investments 60,515 36,245 Total Investments $ 72,698 $ 48,430 Equity Method The carrying amount of our equity method investments totaled $12.2 million as of June 30, 2016 and December 31, 2015 , and is included in Investments in our Condensed Consolidated Balance Sheet. Our equity method investments include our investments in Signal Trading Systems, LLC ("Signal") and CBOE Stock Exchange, LLC ("CBSX"). In May 2010, CBOE acquired a 50% interest in Signal 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 under the equity method due to the substantive participating rights provided to the other limited liability company member, FlexTrade. In the six months ended June 30, 2016 , the Company recorded contributions to Signal of $1.0 million and equity earnings in Signal of $0.5 million . Additionally, the Company received a distribution of $0.5 million which reduced the carrying value of our investment. The Company currently holds a 49.96% equity interest in CBSX in return for non-cash property contributions. 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 CBSX with financial, accounting and technology support. Cost method The carrying amount of our cost method investments totaled $60.5 million and $36.2 million as of June 30, 2016 and December 31, 2015 , respectively, and is included in Investments in our Condensed Consolidated Balance Sheet. We account for investments under the cost-method primarily as a result of our inability to exercise significant influence. As of June 30, 2016 , our cost method investments primarily reflect our 20% investment in OCC and minority investments in American Financial Exchange ("AFX"), CurveGlobal and Eris Exchange Holdings, LLC ("Eris"). As previously reported in our Annual Report on Form 10-K for the year ended December 31, 2015, the SEC approved OCC’s rule change implementing OCC's new capital plan on February 11, 2016. Certain petitioners subsequently appealed the SEC approval order for the OCC capital plan to the U.S. Court of Appeals for the D.C. Circuit and moved to stay the SEC approval order. On February 23, 2016, the Court denied the petitioners’ motion to stay. The appeal of the SEC approval order remains pending. In 2015, CBOE Holdings, through its subsidiary Loan Markets, LLC, acquired a minority interest in AFX, an electronic marketplace for small and mid-sized banks to lend and borrow short-term funds. In January 2016, CBOE Holdings, through its subsidiary CBOE III, LLC, acquired a minority interest in CurveGlobal, a new interest rate derivatives venture. In May 2016, CBOE Holdings, through its subsidiary CBOE III, LLC, acquired a minority interest in Eris, the parent of a U.S. based futures exchange group.

Accounts Payable and Accured Li

Accounts Payable and Accured Liabilities	6 Months Ended
	Jun. 30, 2016
Payables and Accruals [Abstract]
Accounts Payable and Accrued Liabilities	ACCOUNTS PAYABLE AND ACCRUED LIABILITIES As of June 30, 2016 and December 31, 2015 , accounts payable and accrued liabilities consisted of the following (in thousands): June 30, December 31, Compensation and benefit-related liabilities (1) $ 14,459 $ 23,304 Royalties 17,099 15,409 Contract services 7,550 6,684 Accounts payable 1,939 1,762 Purchase of common stock (2) — 1,778 Facilities 2,170 2,099 Legal 2,345 1,536 Market linkage 1,672 628 Other 7,487 6,904 Total $ 54,721 $ 60,104 (1) As of June 30, 2016 , primarily reflects accrued costs for 2016 incentive compensation expense. At December 31, 2015 , primarily reflects 2015 annual accrued incentive compensation, which was paid in the first quarter of 2016 . (2) Reflects shares purchased at the end of the period not settled until three trading days after the trade occurs.

Marketing Fee

Marketing Fee	6 Months Ended
	Jun. 30, 2016
Marketing Fee [Abstract]
Marketing Fees	MARKETING FEE CBOE 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 June 30, 2016 and December 31, 2015 , amounts assessed by the Company on behalf of others included in current assets totaled $7.1 million and $5.7 million , respectively, and payments due to others included in current liabilities totaled $7.5 million and $6.1 million , respectively.

Deferred Revenue

Deferred Revenue	6 Months Ended
	Jun. 30, 2016
Deferred Revenue [Abstract]
Deferred Revenue	DEFERRED REVENUE The following table summarizes the activity in deferred revenue for the six months ended June 30, 2016 (in thousands): Balance at December 31, 2015 Cash Additions Revenue Recognition Balance at June 30, 2016 Other – net $ 4,019 $ 7,716 $ (6,859 ) $ 4,876 Liquidity provider sliding scale (1) — 11,400 (5,400 ) 6,000 Total deferred revenue $ 4,019 $ 19,116 $ (12,259 ) $ 10,876 (1) 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 calendar month. The prepayment of 2016 transaction fees totaled $11.4 million . This amount is amortized and recorded ratably, as transaction fees, over the respective twelve month period.

Employee Benefits

Employee Benefits	6 Months Ended
	Jun. 30, 2016
Employee Benefits [Abstract]
Employee Benefits	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). In addition, 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 under Internal Revenue Code. The Company contributed $2.7 million and $2.2 million to the defined contribution plans for the six months ended June 30, 2016 and 2015 , respectively. The Company has a post-retirement medical plan for former members of senior management. The Company recorded immaterial post-retirement benefits expense for the six months ended June 30, 2016 and 2015 .

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES Income tax provision includes United States federal, state and local taxes and is based on reported pre-tax income. For the three and six months ended June 30, 2016 and 2015 , the Company recorded income tax provisions of $32.9 million and $64.2 million and $28.8 million and $55.8 million , respectively. For the three months ended June 30, 2016 and 2015 the effective tax rate was 39.2% and 39.1% , respectively. The effective tax rate for the six months ended June 30, 2016 and 2015 was 39.1% and 39.0% , respectively. Income tax expense is provided on an interim basis based upon our estimate of the annual effective income tax rate, adjusted each quarter for discrete items. In determining the estimated annual effective income tax rate, we analyze various factors, including projections of our annual earnings and taxing jurisdictions in which the earnings will be generated, the impact of state and local income taxes, and our ability to use tax credits. As of June 30, 2016 and December 31, 2015 , the Company had $32.9 million and $31.9 million , in unrecognized tax benefits, respectively, all of which would favorably impact the effective tax rate if recognized. As of June 30, 2016 and December 31, 2015 , the Company has recognized a liability for interest and penalties of $9.2 million and $7.7 million , respectively. We file income tax returns in the U.S. federal jurisdiction and various state jurisdictions. Federal income tax returns are generally not subject to examination by the Internal Revenue Service ("IRS") for tax years prior to 2008. Tax years open to examination by state and local taxing authorities vary by jurisdiction. We are generally not subject to state or local tax examinations for tax years prior to 2007. The IRS is currently examining tax years 2008 through 2013. The New York State Department of Taxation and Finance is currently examining the returns filed for tax years 2007 through 2012. Tax returns for tax years 2010 through 2012 are currently under examination by the New Jersey Division of Taxation. We have been notified by the Illinois Department of Revenue that it intends to examine our tax returns filed for the 2013 and 2014 tax years.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Disclosures	FAIR VALUE MEASUREMENTS Fair value is the price that would be received upon the sale of an asset or paid upon the 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 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 non-financial 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 condensed consolidated balance sheet as of June 30, 2016 and December 31, 2015 . 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 $ 34,500 $ — $ — $ 34,500 Total assets at fair value at June 30, 2016 $ 34,500 $ — $ — $ 34,500 (amounts in thousands) Level 1 Level 2 Level 3 Total Assets at fair value: Money market funds $ 84,000 $ — $ — $ 84,000 Total assets at fair value at December 31, 2015 $ 84,000 $ — $ — $ 84,000 In 2015, CBOE Holdings, through its subsidiary Loan Markets, LLC, acquired a minority interest in AFX. 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 January 2016, CBOE Holdings, through its subsidiary CBOE III, LLC, acquired a minority interest in CurveGlobal. 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 May 2016, CBOE Holdings, through its subsidiary CBOE III, LLC, acquired a minority interest in Eris. 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. The Company has recorded contingent consideration of $3.4 million through June 30, 2016, categorized as level 3, which is based on management's estimate of the achievement by Livevol of certain performance targets at nine and eighteen months from the acquisition date. If Livevol were to exceed management's estimates it could result in an additional payment in excess of the recorded contingent consideration.

Legal Proceedings

Legal Proceedings	6 Months Ended
	Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Legal Proceedings	NOTE 14 — LEGAL PROCEEDINGS As of June 30, 2016 , the end of the period covered by this report, the Company was subject to various legal proceedings and claims, 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. For a description of each of these proceedings, please see Note 12 to our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2015 . 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 June 30, 2016 , 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. The following information updates the legal proceedings disclosures in our Annual Report on Form 10-K for the year ended December 31, 2015 and subsequent Quarterly Reports on Form 10-Q. ISE -- '707 On November 22, 2006, International Securities Exchange, LLC ("ISE") filed an action in the United States District Court for the Southern District of New York claiming that CBOE's Hybrid trading system infringes ISE's U.S. Patent No. 6,618,707 (the "'707 patent"). On January 31, 2007, CBOE filed an action in federal court in the Northern District of Illinois seeking a declaratory judgment that the '707 patent was not infringed, not valid and/or not enforceable against CBOE. The New York case was transferred to the federal court in the Northern District of Illinois on August 9, 2007. On March 14, 2013, ISE conceded to an adverse judgment in this matter and asked that the federal court in the Northern District of Illinois enter judgment for CBOE. ISE appealed certain court rulings to the Federal Circuit Court of Appeals. The federal court in the Northern District of Illinois on January 14, 2014 issued an opinion and order awarding certain costs associated with the litigation to CBOE. On April 7, 2014, the Federal Circuit Court of Appeals issued a favorable opinion to CBOE. On March 31, 2016, the federal court in the Northern District of Illinois granted CBOE’s motion for attorney fees and expenses and CBOE subsequently supplemented such request on April 7, 2016. On May 18, 2016, ISE agreed with CBOE to settle the amount owed for attorney fees and expenses. Pursuant to such agreement, ISE paid CBOE a total of $5.5 million, recorded in investment and other income, in the second quarter of 2016.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2016
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS On July 28, 2016 , the Company announced that its board of directors declared a quarterly cash dividend of $0.25 per share. The dividend is payable September 16, 2016 to stockholders of record at the close of business on September 2, 2016 .

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2016
Accounting Policies [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements 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 FASB deferred the effective date by one year to December 15, 2017 for annual reporting periods beginning after that date. Early adoption of the standard is permitted, but not before the original effective date of December 15, 2016. 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. In September 2015, the FASB issued ASU 2015-16, Business Combinations . This standard simplifies the accounting for adjustments made to provisional amounts recognized in a business combination. First, it requires that the acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amount is determined. The acquirer also should record, in the same period's financial statements, the effect on earnings of changes in depreciation, amortization, or other income effects, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date. The amendments should be applied prospectively to adjustments to provisional amounts that are identified after December 15, 2015 and that are within the measurement period. Upon transition, an entity would be required to disclose the nature of, and reason for, the change in accounting principle. An entity would provide that disclosure in the first annual period of adoption and in the interim periods within the first annual period. The Company has adopted this guidance, though we do not expect it will materially impact our consolidated balance sheets, statements of income, comprehensive income or cash flows. In February 2016, the FASB issued ASU 2016-02, Leases . This update requires a lessee to recognize on the balance sheet a liability to make lease payments and a corresponding right-of-use asset. The guidance also requires certain qualitative and quantitative disclosures about the amount, timing and uncertainty of cash flows arising from leases. This update is effective for annual and interim periods beginning after December 15, 2018. Early adoption is 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. In March 2016, the FASB issued ASU 2016-09, Compensation — Stock Compensation . This standard simplifies several aspects of the accounting for stock-based payment transactions, including the recognition of excess tax benefits and deficiencies, the classification of those excess tax benefits on the statement of cash flows, an accounting policy election for forfeitures, the amount an employer can withhold to cover income taxes and still qualify for equity classification and the classification of those taxes paid on the statement of cash flows. This update is effective for annual and interim periods beginning after December 15, 2016 and can be applied either prospectively, retrospectively or using a modified retrospective transition method, depending on the area covered in this update. Early adoption is 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.

Acquisitions- Goodwill and In25

Acquisitions- Goodwill and Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2016
Business Combinations [Abstract]
Allocation of Purchase Price	The purchase price was allocated on a preliminary basis, subject to final allocation, to the assets acquired based on their fair values at the acquisition date. (amounts in thousands) Purchase Price $ 18,900 Fair Value of Assets Acquired: Cash $ 4,700 Intangible assets 8,000 Goodwill 18,800 Total Assets Acquired $ 31,500 Redeemable noncontrolling interests 12,600 Net Assets Acquired $ 18,900
Schedule of Acquired Intangible Assets	Intangible assets totaling $2.6 million were recorded in 2015 in connection with the acquisition of Livevol include: customer relationships, trade names, existing technology, non-compete agreements and leasehold rights. Intangible assets and related accumulated amortization consisted of the following as of June 30, 2016 (in thousands): As of June 30, 2016 Estimated Useful Lives Customer relationships $ 910 13 years Trade names 370 10 years Technology 1,130 2-5 years Other 150 1-4 years Total 2,560 Less accumulated amortization 400 Total Intangibles, net $ 2,160 Intangible assets totaling $8.0 million were recorded in 2016 in connection with the acquisition of Vest and include: customer relationships, trade names, and technology. Intangible assets and related accumulated amortization consisted of the following as of June 30, 2016 (in thousands): As of June 30, 2016 Estimated Useful Lives Customer relationships $ 3,000 9 years Trade names 1,000 7 years Technology 4,000 5 years Total Intangible Assets Acquired 8,000 Less accumulated amortization 638 Total Intangibles, net $ 7,362
Intangible Assets Amortization Schedule	For the three and six months ended June 30, 2016 , amortization of Vest intangible assets was $0.3 million and $0.6 million , respectively. The remaining weighted average useful lives of the intangible assets is 5.9 years as of June 30, 2016 . The future expected amortization expense from the intangible assets related to the Vest acquisition as of June 30, 2016 is as follows (in thousands): Year Amortization expense 2016 (1) $ 638 2017 1,276 2018 1,276 2019 1,276 2020 1,276 Total $ 5,742 For the three and six months ended June 30, 2016 , amortization of Livevol intangible assets was $0.1 million and $0.2 million , respectively. The remaining weighted average useful lives of the intangible assets is 7.8 years as of June 30, 2016 . The future expected amortization expense from the intangible assets related to the Livevol acquisition as of June 30, 2016 is as follows (in thousands): Year Amortization expense 2016 (1) $ 217 2017 379 2018 349 2019 309 2020 206 Total $ 1,460

Redeemable Noncontrolling Int26

Redeemable Noncontrolling Interest (Tables)	6 Months Ended
	Jun. 30, 2016
Equity [Abstract]
Redeemable Noncontrolling Interest	For the six months ended June 30, 2016 , the following reflects changes in our redeemable noncontrolling interests (in thousands): Redeemable Noncontrolling Interest Balance as of January 1, 2016 $ — Increase due to acquiring majority of outstanding equity of Vest 12,600 Net loss attributable to redeemable noncontrolling interest (523 ) Redemption value adjustment 523 Balance as of June 30, 2016 $ 12,600

Net Income per Common Share (Ta

Net Income per Common Share (Tables)	6 Months Ended
	Jun. 30, 2016
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table reconciles net income allocated to common stockholders and the number of shares used to calculate the basic and diluted net income per common share for the three and six months ended June 30, 2016 and 2015 : Three Months Ended June 30, Six Months Ended June 30, (in thousands, except per share amounts) 2016 2015 2016 2015 Basic EPS Numerator: Net Income $ 50,931 $ 44,845 $ 100,107 $ 87,105 Loss attributable to noncontrolling interests 299 — 523 — Net income excluding noncontrolling interests 51,230 44,845 100,630 87,105 Change in redemption value of noncontrolling interest (299 ) — (523 ) — Earnings allocated to participating securities (212 ) (199 ) (414 ) (379 ) Net Income allocated to common stockholders $ 50,719 $ 44,646 $ 99,693 $ 86,726 Basic EPS Denominator: Weighted average shares outstanding 81,343 83,290 81,580 83,621 Basic Net Income Per Common Share $ 0.62 $ 0.54 $ 1.22 $ 1.04 Diluted EPS Numerator: Net Income $ 50,931 $ 44,845 $ 100,107 $ 87,105 Loss attributable to noncontrolling interests 299 — 523 — Net income excluding noncontrolling interests 51,230 44,845 100,630 87,105 Change in redemption value of noncontrolling interest (299 ) — (523 ) — Earnings allocated to participating securities (212 ) (199 ) (414 ) (379 ) Net Income allocated to common stockholders $ 50,719 $ 44,646 $ 99,693 $ 86,726 Diluted EPS Denominator: Weighted average shares outstanding 81,343 83,290 81,580 83,621 Dilutive common shares issued under stock program — — — — Diluted Net Income Per Common Share $ 0.62 $ 0.54 $ 1.22 $ 1.04 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.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2016
Share-based Compensation [Abstract]
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	The activity in the Company’s restricted stock and restricted stock units for the six months ended June 30, 2016 was as follows: Number of Shares Weighted Average Unvested at January 1, 2016 456,570 $ 55.70 Granted 241,681 64.10 Vested (211,235 ) 48.14 Forfeited (4,133 ) 59.67 Unvested at June 30, 2016 482,883 $ 63.34

Investments (Tables)

Investments (Tables)	6 Months Ended
	Jun. 30, 2016
Investments in and Advances to Affiliates, Schedule of Investments [Abstract]
Investments in and Advances to Affiliates	At June 30, 2016 and December 31, 2015 , the Company's investments were comprised of the following (in thousands): June 30, December 31, Equity Method Investment in Signal Trading Systems, LLC 12,183 12,185 Investment in CBOE Stock Exchange, LLC — — Total equity method investments 12,183 12,185 Cost Method Investment in OCC 30,333 30,333 Other cost method investments 30,182 5,912 Total cost method investments 60,515 36,245 Total Investments $ 72,698 $ 48,430

Accounts Payable and Accured 30

Accounts Payable and Accured Liabilities (Tables)	6 Months Ended
	Jun. 30, 2016
Payables and Accruals [Abstract]
Schedule of Accounts Payable and Accrued Liabilities	As of June 30, 2016 and December 31, 2015 , accounts payable and accrued liabilities consisted of the following (in thousands): June 30, December 31, Compensation and benefit-related liabilities (1) $ 14,459 $ 23,304 Royalties 17,099 15,409 Contract services 7,550 6,684 Accounts payable 1,939 1,762 Purchase of common stock (2) — 1,778 Facilities 2,170 2,099 Legal 2,345 1,536 Market linkage 1,672 628 Other 7,487 6,904 Total $ 54,721 $ 60,104 (1) As of June 30, 2016 , primarily reflects accrued costs for 2016 incentive compensation expense. At December 31, 2015 , primarily reflects 2015 annual accrued incentive compensation, which was paid in the first quarter of 2016 . (2) Reflects shares purchased at the end of the period not settled until three trading days after the trade occurs.

Deferred Revenue (Tables)

Deferred Revenue (Tables)	6 Months Ended
	Jun. 30, 2016
Deferred Revenue [Abstract]
Deferred Revenue, by Arrangement, Disclosure	The following table summarizes the activity in deferred revenue for the six months ended June 30, 2016 (in thousands): Balance at December 31, 2015 Cash Additions Revenue Recognition Balance at June 30, 2016 Other – net $ 4,019 $ 7,716 $ (6,859 ) $ 4,876 Liquidity provider sliding scale (1) — 11,400 (5,400 ) 6,000 Total deferred revenue $ 4,019 $ 19,116 $ (12,259 ) $ 10,876

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value, Measurement Inputs, Disclosure	The Company has included a tabular disclosure for financial assets that are measured at fair value on a recurring basis in the condensed consolidated balance sheet as of June 30, 2016 and December 31, 2015 . 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 $ 34,500 $ — $ — $ 34,500 Total assets at fair value at June 30, 2016 $ 34,500 $ — $ — $ 34,500 (amounts in thousands) Level 1 Level 2 Level 3 Total Assets at fair value: Money market funds $ 84,000 $ — $ — $ 84,000 Total assets at fair value at December 31, 2015 $ 84,000 $ — $ — $ 84,000

Acquisitions- Goodwill and In33

Acquisitions- Goodwill and Intangible Assets (Vest-Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Purchase price		$ 14,257	$ 0
Goodwill	$ 26,468	26,468		$ 7,655
Vest Financial [Member]
Amortization of intangible assets	$ 300	$ 600
Estimated Useful Lives		5 years 320 days
Purchase price		$ 18,900
Amount paid to Vest owners		14,900
Payments to Vest for newly issued shares		$ 4,000
Ownership interest acquired	60.00%	60.00%
Ownership percentage held by noncontrolling owners	40.00%	40.00%
Goodwill	$ 18,800	$ 18,800
Intangible assets	$ 8,000	$ 8,000

Acquisitions- Goodwill and In34

Acquisitions- Goodwill and Intangible Assets (Vest-Allocation of Purchase Price) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Business Acquisition [Line Items]
Purchase price	$ 14,257	$ 0
Fair Value of Assets Acquired:
Goodwill	26,468		$ 7,655
Redeemable noncontrolling interests	12,600		$ 0
Vest Financial [Member]
Business Acquisition [Line Items]
Purchase price	18,900
Fair Value of Assets Acquired:
Cash	4,700
Intangible assets	8,000
Goodwill	18,800
Total Assets Acquired	31,500
Redeemable noncontrolling interests	12,600
Net Assets Acquired	$ 18,900

Acquisitions- Goodwill and In35

Acquisitions- Goodwill and Intangible Assets (Vest-Intangible Assets) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Less accumulated amortization	$ 1,038,000	$ 182,000
Total Intangibles, net	9,522,000	$ 2,378,000
Vest Financial [Member]
Business Acquisition [Line Items]
Intangible assets	$ 8,000,000
Estimated Useful Lives	5 years 320 days
Less accumulated amortization	$ 638,000
Total Intangibles, net	7,362,000
Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets	$ 3,000,000
Estimated Useful Lives	9 years
Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets	$ 1,000,000
Estimated Useful Lives	7 years
Technology [Member]
Business Acquisition [Line Items]
Intangible assets	$ 4,000,000
Estimated Useful Lives	5 years

Acquisitions- Goodwill and In36

Acquisitions- Goodwill and Intangible Assets (Vest-Amortization Expense) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Total Other Assets—Net	$ 67,562	$ 59,311
Vest Financial [Member]
Business Acquisition [Line Items]
2,016	638
2,017	1,276
2,018	1,276
2,019	1,276
2,020	1,276
Total Other Assets—Net	$ 5,742

Acquisitions- Goodwill and In37

Acquisitions- Goodwill and Intangible Assets (Livevol-Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Business Acquisition [Line Items]
Purchase price		$ 14,257	$ 0
Goodwill	$ 26,468	26,468		$ 7,655
Contingent consideration	3,434	3,434		$ 2,000
Livevol [Member]
Business Acquisition [Line Items]
Purchase price		7,000
Amount paid to existing debt holders		4,000
Amount paid to Livevol owners		3,000
Tangible assets	100	100
Intangible assets	2,560	2,560
Goodwill	7,700	7,700
Contingent consideration	3,400	3,400
Amortization of intangible assets	$ 100	$ 200
Estimated Useful Lives		7 years 9 months 25 days

Acquisitions- Goodwill and In38

Acquisitions- Goodwill and Intangible Assets (Livevol-Intangible Assets) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Less accumulated amortization	$ 1,038,000	$ 182,000
Total Intangibles, net	9,522,000	$ 2,378,000
Livevol [Member]
Business Acquisition [Line Items]
Intangible assets	$ 2,560,000
Estimated Useful Lives	7 years 9 months 25 days
Less accumulated amortization	$ 400,000
Total Intangibles, net	2,160,000
Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets	$ 3,000,000
Estimated Useful Lives	9 years
Customer Relationships [Member] | Livevol [Member]
Business Acquisition [Line Items]
Intangible assets	$ 910,000
Estimated Useful Lives	13 years
Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets	$ 1,000,000
Estimated Useful Lives	7 years
Trade Names [Member] | Livevol [Member]
Business Acquisition [Line Items]
Intangible assets	$ 370,000
Estimated Useful Lives	10 years
Technology [Member]
Business Acquisition [Line Items]
Intangible assets	$ 4,000,000
Estimated Useful Lives	5 years
Technology [Member] | Minimum [Member]
Business Acquisition [Line Items]
Estimated Useful Lives	2 years
Technology [Member] | Maximum [Member]
Business Acquisition [Line Items]
Estimated Useful Lives	5 years
Technology [Member] | Livevol [Member]
Business Acquisition [Line Items]
Intangible assets	$ 1,130,000
Other [Member] | Minimum [Member]
Business Acquisition [Line Items]
Estimated Useful Lives	1 year
Other [Member] | Maximum [Member]
Business Acquisition [Line Items]
Estimated Useful Lives	4 years
Other [Member] | Livevol [Member]
Business Acquisition [Line Items]
Intangible assets	$ 150,000

Acquisitions- Goodwill and In39

Acquisitions- Goodwill and Intangible Assets (Livevol-Schedule of Amortization Expense) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Total	$ 67,562	$ 59,311
Livevol [Member]
Business Acquisition [Line Items]
2,016	217
2,017	379
2,018	349
2,019	309
2,020	206
Total	$ 1,460

Redeemable Noncontrolling Int40

Redeemable Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Increase (Decrease) in Temporary Equity [Roll Forward]
Redeemable Noncontrolling Interests, beginning value			$ 0
Increase due to acquiring majority of outstanding equity of Vest			12,600
Loss attributable to noncontrolling interests	$ (299)	$ 0	(523)	$ 0
Redeemable Noncontrolling Interests, ending value	$ 12,600		$ 12,600

Net Income per Common Share (De

Net Income per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Net Income	$ 50,931	$ 44,845	$ 100,107	$ 87,105
Loss attributable to noncontrolling interests	(299)	0	(523)	0
Change in redemption value of noncontrolling interest	(299)	0	(523)	0
Net Income Excluding Noncontrolling Interests	51,230	44,845	100,630	87,105
Earnings allocated to participating securities	212	199	414	379
Net Income allocated to common stockholders	$ 50,719	$ 44,646	$ 99,693	$ 86,726
Basic EPS Denominator:
Weighted average shares outstanding	81,343	83,290	81,580	83,621
Basic Net Income Per Common Share (in dollars per share)	$ 0.62	$ 0.54	$ 1.22	$ 1.04
Diluted EPS Denominator:
Weighted average shares outstanding	81,343	83,290	81,580	83,621
Dilutive common shares issued under stock program	0	0	0	0
Diluted Net Income Per Common Share (in dollars per share)	$ 0.62	$ 0.54	$ 1.22	$ 1.04

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) $ / shares in Units, $ in Thousands	May 19, 2016$ / sharesshares	Feb. 20, 2016$ / sharesshares	Feb. 19, 2016$ / sharesshares	Jun. 30, 2016USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2016USD ($)$ / sharesshares	Jun. 30, 2015USD ($)
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Equity instruments other than options, grants in period (in shares) | shares						241,681
Equity instruments other than options, grants in period, weighted average grant date fair value (in USD per share) | $ / shares						$ 64.10
Stock-based compensation expense | $				$ 3,700	$ 3,100	$ 7,105	$ 5,801
Accelerated compensation cost | $				300		500
Unrecognized stock-based compensation expense | $				$ 25,300		$ 25,300
Unrecognized stock-based compensation expense, period for recognition						26 months 24 days
Restricted Stock Units (RSUs) [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Equity instruments other than options, grants in period (in shares) | shares		170,081
Equity instruments other than options, grants in period, weighted average grant date fair value (in USD per share) | $ / shares		$ 61.80
Performance Shares [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Equity instruments other than options, grants in period (in shares) | shares	20,553		49,238
Equity instruments other than options, grants in period, weighted average grant date fair value (in USD per share) | $ / shares	$ 63.29
Award vesting period	12 months
Risk free interest rate			0.90%
Expected volatility rate			21.10%
Correlation with S&P 500			0.41
Performance Shares [Member] | Minimum [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares which may be awarded if performance conditions are met			0.00%
Performance Shares [Member] | Maximum [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares which may be awarded if performance conditions are met			200.00%
Earnings Per Share [Member] | Performance Shares [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Equity instruments other than options, grants in period (in shares) | shares			24,619
Equity instruments other than options, grants in period, weighted average grant date fair value (in USD per share) | $ / shares			$ 61.80
Total Shareholder Return [Member] | Performance Shares [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Equity instruments other than options, grants in period (in shares) | shares			24,619
Equity instruments other than options, grants in period, weighted average grant date fair value (in USD per share) | $ / shares			$ 83

Stock-Based Compensation (Resti

Stock-Based Compensation (Resticted Stock Units) (Details) - $ / shares	May 19, 2016	Feb. 20, 2016	Feb. 19, 2016	Jun. 30, 2016
Unrecognized stock-based compensation expense, period for recognition				26 months 24 days
Number of Shares
Beginning balance (in shares)				456,570
Granted (in shares)				241,681
Vested (in shares)				(211,235)
Forfeited (in shares)				(4,133)
Ending balance (in shares)				482,883
Weighted Average Grant Date Fair Value
Beginning balance (in USD per share)				$ 55.70
Granted (in USD per share)				64.10
Vested (in USD per share)				48.14
Forfeited (in USD per share)				59.67
Ending balance (in USD per share)				$ 63.34
Restricted Stock Units (RSUs) [Member]
Number of Shares
Granted (in shares)		170,081
Weighted Average Grant Date Fair Value
Granted (in USD per share)		$ 61.80
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	12 months
Number of Shares
Granted (in shares)	20,553		49,238
Weighted Average Grant Date Fair Value
Granted (in USD per share)	$ 63.29
Earnings Per Share [Member] | Performance Shares [Member]
Number of Shares
Granted (in shares)			24,619
Weighted Average Grant Date Fair Value
Granted (in USD per share)			$ 61.80
Total Shareholder Return [Member] | Performance Shares [Member]
Number of Shares
Granted (in shares)			24,619
Weighted Average Grant Date Fair Value
Granted (in USD per share)			$ 83

Investments (Details)

Investments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Equity method investments	$ 12,183		$ 12,183		$ 12,185
Cost method investments	60,515		60,515		36,245
Investments	72,698		72,698		48,430
Net income/(loss) from investments	$ 218	$ 202	$ 524	$ (125)
Cost method investment, ownership percentage	20.00%		20.00%
Investment in Signal Trading Systems, LLC [Member]
Equity method investments	$ 12,183		$ 12,183		12,185
Equity method investment, ownership percentage	50.00%		50.00%
Payments to acquire investments	$ 1,000
Net income/(loss) from investments			$ 500
Distributions which reduce carrying value of investments	500
Investment in CBOE Stock Exchange, LLC [Member] [Member]
Equity method investments	$ 0		$ 0		0
Equity method investment, ownership percentage	49.96%		49.96%
Investment in OCC [Member]
Cost method investments	$ 30,333		$ 30,333		30,333
Other Cost Method Investments [Member]
Cost method investments	$ 30,182		$ 30,182		$ 5,912

Accounts Payable and Accured 45

Accounts Payable and Accured Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Compensation and benefit-related liabilities	$ 14,459	$ 23,304
Royalties	17,099	15,409
Contract services	7,550	6,684
Accounts payable	1,939	1,762
Purchase of common stock	0	1,778
Facilities	2,170	2,099
Legal	2,345	1,536
Market linkage	1,672	628
Other	7,487	6,904
Total	$ 54,721	$ 60,104

Marketing Fee (Details)

Marketing Fee (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Marketing Fee [Abstract]
Marketing fee receivable	$ 7,052	$ 5,682
Marketing fee payable	$ 7,532	$ 6,141

Deferred Revenue (Details)

Deferred Revenue (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2016USD ($)
Deferred Revenue [Roll Forward]
Balance at December 31, 2015	$ 4,019
Cash Additions	19,116
Revenue Recognition	(12,259)
Balance at June 30, 2016	10,876
Other – net
Deferred Revenue [Roll Forward]
Balance at December 31, 2015	4,019
Cash Additions	7,716
Revenue Recognition	(6,859)
Balance at June 30, 2016	4,876
Liquidity Provider Sliding Scale
Deferred Revenue [Roll Forward]
Balance at December 31, 2015	0
Cash Additions	11,400
Revenue Recognition	(5,400)
Balance at June 30, 2016	$ 6,000

Employee Benefits (Details)

Employee Benefits (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Employee Benefits [Abstract]
Contributions by employer	$ 2.7	$ 2.2

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income tax provision	$ 32,883	$ 28,786	$ 64,175	$ 55,804
Effective tax rate	39.20%	39.10%	39.10%	39.00%
Unrecognized tax benefits	$ 32,900		$ 32,900		$ 31,900
Unrecognized tax benefits, liability for interest and penalties	$ 9,200		$ 9,200		$ 7,700

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Contingent consideration - long term	$ 0	$ 1,379

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Money market funds	$ 34,500	$ 84,000
Assets at fair value	34,500	84,000
Contingent consideration	3,434	2,000
Level 1
Money market funds	34,500	84,000
Assets at fair value	34,500	84,000
Level 2
Money market funds	0	0
Assets at fair value	0	0
Level 3
Money market funds	0	0
Assets at fair value	$ 0	$ 0

Legal Proceedings Legal Proceed

Legal Proceedings Legal Proceedings (Details) $ in Millions	3 Months Ended
	Jun. 30, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
Cash received from settlement with ISE	$ 5.5

Subsequent Events (Details)

Subsequent Events (Details)	Jul. 28, 2016$ / shares
Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends declared	$ 0.25