MarketAxess (MKTX) 10-K 21 Feb 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2016	Feb. 16, 2017	Jun. 30, 2016
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Trading Symbol	MKTX
Entity Registrant Name	MARKETAXESS HOLDINGS INC
Entity Central Index Key	1,278,021
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		37,586,345
Entity Public Float			$ 5.3

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
ASSETS
Cash and cash equivalents	$ 168,243	$ 199,728
Investments, at fair value	194,404	84,706
Accounts receivable, net of allowance of $82 and $109 as of December 31, 2016 and December 31, 2015, respectively	50,668	40,459
Goodwill and intangible assets, net of accumulated amortization	63,443	64,142
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	31,104	30,897
Prepaid expenses and other assets	11,618	9,880
Deferred tax assets, net	8,562	9,229
Total assets	528,042	439,041
Liabilities
Accrued employee compensation	34,783	29,296
Income and other tax liabilities	7,582	4,463
Deferred revenue	2,515	2,312
Accounts payable, accrued expenses and other liabilities	15,149	12,257
Total liabilities	60,029	48,328
Commitments and Contingencies (Note 12)
Stockholders’ equity
Additional paid-in capital	342,311	321,215
Treasury stock - Common stock voting, at cost, 2,562,585 shares and 2,412,245 shares as of December 31, 2016 and December 31, 2015, respectively	(117,330)	(93,405)
Retained earnings	255,140	168,011
Accumulated other comprehensive loss	(12,228)	(5,229)
Total stockholders’ equity	468,013	390,713
Total liabilities and stockholders’ equity	528,042	439,041
Undefined Preferred Stock [Member]
Stockholders’ equity
Preferred stock
Series A Preferred Stock [Member]
Stockholders’ equity
Preferred stock
Voting Common Stock [Member]
Stockholders’ equity
Common stock	$ 120	$ 121

Consolidated Statements of Fin3

Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Allowance for accounts receivable	$ 82	$ 109
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	4,855,000	4,855,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.003	$ 0.003
Common stock, shares authorized	110,000,000	110,000,000
Common stock, shares issued	40,106,360	39,821,519
Common stock, shares outstanding	37,543,775	37,409,274
Treasury stock, shares	2,562,585	2,412,245
Series A Preferred Stock [Member]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	110,000	110,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common Stock Non-Voting [Member]
Common stock, par value	$ 0.003	$ 0.003
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares issued	0	0
Common stock, shares outstanding	0	0

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues
Commissions	$ 332,307	$ 266,221	$ 221,138
Information and post-trade services	31,225	30,660	31,510
Investment income	2,137	905	543
Other	4,250	5,312	9,583
Total revenues	369,919	303,098	262,774
Expenses
Employee compensation and benefits	96,785	83,856	74,995
Depreciation and amortization	17,838	18,542	17,379
Technology and communications	17,275	15,916	17,685
Professional and consulting fees	17,175	13,043	14,375
Occupancy	4,681	4,685	4,381
Marketing and advertising	8,934	6,148	5,769
General and administrative	15,629	13,008	9,654
Total expenses	178,317	155,198	144,238
Income before income taxes	191,602	147,900	118,536
Provision for income taxes	65,430	51,863	43,730
Net income	$ 126,172	$ 96,037	$ 74,806
Net income per common share
Basic	$ 3.42	$ 2.62	$ 2.03
Diluted	3.34	2.55	1.97
Cash dividends declared per common share	$ 1.04	$ 0.80	$ 0.64
Weighted average shares outstanding
Basic	36,844	36,690	36,930
Diluted	37,738	37,637	37,889

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 126,172	$ 96,037	$ 74,806
Net cumulative translation adjustment and foreign currency exchange hedge, net of tax of $5,407, $(258) and $(275), respectively	(7,037)	(512)	(399)
Net unrealized gain (loss) on securities available-for-sale, net of tax of $24, $(111), and $(9), respectively	38	(180)	(16)
Less: reclassification adjustment for realized gain on the sale of securities available-for-sale included in Other Income, net of tax of $(0), $(0) and $(24), respectively			(39)
Net change in unrealized gain (loss) on securities available-for-sale, net of tax	38	(180)	(55)
Comprehensive income	$ 119,173	$ 95,345	$ 74,352

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Foreign currency exchange hedge, tax expense (benefit)	$ 5,407	$ (258)	$ (275)
Securities available-for-sale, tax expense (benefit)	24	(111)	(9)
Sale of securities available- for-sale included in Other Income, tax benefit	$ 0	$ 0	$ (24)

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock Voting [Member]	Additional Paid-in Capital [Member]	Treasury Stock - Common Stock Voting [Member]	Retained Earnings (Deficit) [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Dec. 31, 2013	$ 310,362	$ 119	$ 295,557	$ (32,273)	$ 51,042	$ (4,083)
Net income	74,806				74,806
Cumulative translation adjustment and foreign currency exchange hedge, net of tax	(399)					(399)
Unrealized net gain (loss) on securities available-for-sale, net of tax	(55)					(55)
Stock-based compensation	9,769		9,769
Exercise of stock options	2,511	1	2,510
Withholding tax payments on restricted stock vesting and stock option exercises	(5,020)		(5,020)
Excess tax benefits from stock-based compensation	4,243		4,243
Repurchases of common stock	(37,974)			(37,974)
Cash dividend on common stock	(24,035)				(24,035)
Ending Balance at Dec. 31, 2014	334,208	120	307,059	(70,247)	101,813	(4,537)
Net income	96,037				96,037
Cumulative translation adjustment and foreign currency exchange hedge, net of tax	(512)					(512)
Unrealized net gain (loss) on securities available-for-sale, net of tax	(180)					(180)
Stock-based compensation	12,519		12,519
Exercise of stock options	1,824	1	1,823
Withholding tax payments on restricted stock vesting and stock option exercises	(4,496)		(4,496)
Excess tax benefits from stock-based compensation	4,310		4,310
Repurchases of common stock	(23,158)			(23,158)
Cash dividend on common stock	(29,839)				(29,839)
Ending Balance at Dec. 31, 2015	390,713	121	321,215	(93,405)	168,011	(5,229)
Net income	126,172				126,172
Cumulative translation adjustment and foreign currency exchange hedge, net of tax	(7,037)					(7,037)
Unrealized net gain (loss) on securities available-for-sale, net of tax	38					38
Stock-based compensation	14,511		14,511
Exercise of stock options	2,299		2,299
Withholding tax payments on restricted stock vesting and stock option exercises	(5,173)	(1)	(5,172)
Excess tax benefits from stock-based compensation	9,458		9,458
Repurchases of common stock	(23,925)			(23,925)
Cash dividend on common stock	(39,043)				(39,043)
Ending Balance at Dec. 31, 2016	$ 468,013	$ 120	$ 342,311	$ (117,330)	$ 255,140	$ (12,228)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities
Net income	$ 126,172	$ 96,037	$ 74,806
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	17,838	18,542	17,379
Stock-based compensation expense	14,511	12,519	9,769
Deferred taxes	(2,581)	(2,424)	(374)
Other	1,170	2,049	1,725
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable	(10,429)	(6,748)	827
(Increase) decrease in prepaid expenses and other assets	(2,125)	(2,662)	3,344
Increase in accrued employee compensation	5,487	3,986	1,309
Increase (decrease) in income and other tax liabilities	3,221	(941)	2,365
Increase (decrease) in deferred revenue	203	(153)	(248)
Increase (decrease) in accounts payable, accrued expenses and other liabilities	2,344	(9)	(950)
Net cash provided by operating activities	80,289	120,196	109,952
Cash flows from investing activities
Proceeds from maturities and sales, available-for-sale investments	46,347	35,248	17,574
Purchase, available-for-sale investments	(81,438)	(57,175)	(16,423)
Purchases of furniture, equipment and leasehold improvements	(6,385)	(4,795)	(4,627)
Capitalization of software development costs	(12,118)	(10,589)	(10,160)
Other	414	(642)	611
Net cash (used in) investing activities	(53,180)	(37,953)	(13,025)
Cash flows from financing activities
Cash dividend on common stock	(38,495)	(29,534)	(23,941)
Exercise of stock options	2,299	1,824	2,511
Withholding tax payments on restricted stock vesting and stock option exercises	(5,173)	(4,496)	(5,020)
Excess tax benefits from stock-based compensation	9,458	4,310	4,243
Repurchases of common stock	(23,925)	(23,158)	(37,974)
Other			(42)
Net cash (used in) financing activities	(55,836)	(51,054)	(60,223)
Effect of exchange rate changes on cash and cash equivalents	(2,758)	(385)	(471)
Cash and cash equivalents
Net (decrease) increase for the period	(31,485)	30,804	36,233
Beginning of period	199,728	168,924	132,691
End of period	168,243	199,728	168,924
Cash paid during the year
Cash paid for income taxes	58,268	$ 50,875	$ 33,627
Corporate Debt [Member]
Changes in operating assets and liabilities:
(Increase) in trading securities	(74,195)
Mutual Funds Held In Rabbi Trust [Member]
Changes in operating assets and liabilities:
(Increase) in trading securities	$ (1,327)

Organization and Principal Busi

Organization and Principal Business Activity	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Organization and Principal Business Activity	1. Organization and Principal Business Activity MarketAxess Holdings Inc. (the “Company” or “MarketAxess”) was incorporated in the State of Delaware on April 11, 2000. Through its subsidiaries, MarketAxess operates a leading electronic trading platform that enables fixed-income market participants to efficiently trade corporate bonds and other types of fixed-income instruments using MarketAxess’ patented trading technology. Over 1,200 institutional investor and broker-dealer firms are active users of the MarketAxess trading platform, accessing global liquidity in U.S. high-grade corporate bonds, emerging markets and high-yield bonds, European bonds, U.S. agency bonds, municipal bonds, credit default swaps and other fixed-income securities. Through its Open Trading™ protocols, MarketAxess executes certain bond transactions between and among institutional investor and broker-dealer clients on a matched principal basis by serving as counterparty to both the buyer and the seller in trades which then settle through a third-party clearing broker. MarketAxess also offers a number of trading-related products and services, including: market data to assist clients with trading decisions; connectivity solutions that facilitate straight-through processing; technology services to optimize trading environments; and execution services for exchange-traded fund managers and other clients. Through its Trax ®

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies Basis of Presentation The consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany transactions and balances have been eliminated. Cash and Cash Equivalents Cash and cash equivalents includes cash and money market instruments that are primarily maintained at one major global bank. Given this concentration, the Company is exposed to certain credit risk in relation to its deposits at this bank. The Company defines cash equivalents as short-term interest-bearing investments with maturities at the time of purchase of three months or less. Investments The Company determines the appropriate classification of securities at the time of purchase which are recorded in the Consolidated Statements of Financial Condition on the trade date. Securities are classified as available-for-sale or trading. The Company’s available-for-sale investments are comprised of municipal bonds and investment grade corporate debt securities. Available-for-sale investments are carried at fair value with the unrealized gains or losses reported in accumulated other comprehensive loss in the Consolidated Statements of Financial Condition. Trading investments primarily include investment grade corporate debt securities and are carried at fair value, with realized and unrealized gains or losses included in other income in the Consolidated Statements of Operations. The Company assesses whether an other-than-temporary impairment loss on the available-for-sale investments has occurred due to declines in fair value or other market conditions. The portion of an other-than-temporary impairment related to credit loss is recorded as a charge in the Consolidated Statements of Operations. The remainder is recognized in accumulated other comprehensive loss if the Company does not intend to sell the security and it is more likely than not that the Company will not be required to sell the security prior to recovery. No charges for other-than-temporary losses were recorded during the years ended December 31, 2016, 2015 and 2014. Fair Value Financial Instruments Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” A three-tiered hierarchy for determining fair value has been established that prioritizes inputs to valuation techniques used in fair value calculations. The three levels of inputs are defined as Level 1 (unadjusted quoted prices for identical assets or liabilities in active markets), Level 2 (inputs that are observable in the marketplace other than those inputs classified in Level 1) and Level 3 (inputs that are unobservable in the marketplace). The Company’s financial assets and liabilities measured at fair value on a recurring basis consist of its money market funds, securities available-for-sale, trading securities and foreign currency forward contracts. All other financial instruments are short-term in nature and the carrying amount is reported on the Consolidated Statements of Financial Condition at approximate fair value. Allowance for Doubtful Accounts All accounts receivable have contractual maturities of less than one year and are derived from trading-related fees and commissions and revenues from products and services. The Company continually monitors collections and payments from its customers and maintains an allowance for doubtful accounts. The allowance for doubtful accounts is based upon the historical collection experience and specific collection issues that have been identified. Additions to the allowance for doubtful accounts are charged to bad debt expense, which is included in general and administrative expense in the Company’s Consolidated Statements of Operations. The allowance for doubtful accounts was $0.1 million, $0.1 million and $0.0 million as of December 31, 2016, 2015 and 2014, respectively. The provision for bad debts was $0.2 million, $0.2 million and $0.1 million for the years ended December 31, 2016, 2015 and 2014, respectively. Write-offs and other charges against the allowance for doubtful accounts were $0.1 million, $0.1 million and $0.0 million for the years ended December 31, 2016, 2015 and 2014, respectively. Depreciation and Amortization Fixed assets are carried at cost less accumulated depreciation. The Company uses the straight-line method of depreciation over three to seven years. The Company amortizes leasehold improvements on a straight-line basis over the lesser of the life of the improvement or the remaining term of the lease. Software Development Costs The Company capitalizes certain costs associated with the development of internal use software, including among other items, employee compensation and related benefits and third party consulting costs at the point at which the conceptual formulation, design and testing of possible software project alternatives have been completed. Once the product is ready for its intended use, such costs are amortized on a straight-line basis over three years. The Company reviews the amounts capitalized for impairment whenever events or changes in circumstances indicate that the carrying amounts of the assets may not be recoverable. Cash Provided as Collateral Cash is provided as collateral for broker-dealer clearing accounts. Cash provided as collateral is included in prepaid expenses and other assets in the Consolidated Statements of Financial Condition. Foreign Currency Translation and Forward Contracts Assets and liabilities denominated in foreign currencies are translated using exchange rates at the end of the period; revenues and expenses are translated at average monthly rates. Gains and losses on foreign currency translation are a component of accumulated other comprehensive loss in the Consolidated Statements of Financial Condition. Transaction gains and losses are recorded in general and administrative expense in the Consolidated Statements of Operations. The Company enters into foreign currency forward contracts to hedge its net investment in its U.K. subsidiaries. Gains and losses on these transactions are included in accumulated other comprehensive loss in the Consolidated Statements of Financial Condition. Revenue Recognition The majority of the Company’s revenues are derived from commissions for trades executed on its platform and distribution fees that are billed to its broker-dealer clients on a monthly basis. The Company also derives revenues from information and post-trade services, technology products and services, investment income and other income. Commission revenue. Commissions are generally calculated as a percentage of the notional dollar volume of bonds traded on the platform and vary based on the type, size, yield and maturity of the bond traded. Under the Company’s transaction fee plans, bonds that are more actively traded or that have shorter maturities are generally charged lower commissions, while bonds that are less actively traded or that have longer maturities generally command higher commissions. For trades that the Company executes between and among institutional investor and broker-dealer clients on a matched principal basis by serving as counterparty to both the buyer and the seller, the Company earns the commission through the difference in price between the two matched principal trades. Fee programs for certain products include distribution fees which are recognized monthly. Information and post-trade services. The Company generates revenue from information services provided to our broker-dealer clients, institutional investor clients and data-only subscribers. Information services are invoiced monthly, quarterly or annually. When billed in advance, revenues are deferred and recognized monthly on a straight-line basis. The Company also generates revenue from regulatory transaction reporting and trade matching services. Revenue is recognized in the period the services are provided. Technology products and services. The Company generates revenues from professional consulting services, technology software licenses and maintenance and support services. Revenue from professional consulting services is recognized as services are performed and software license subscription revenue and maintenance and support services are recognized ratably over the contract period. Technology products and services revenue is reported in other income in the Consolidated Statements of Operations. Initial set-up fees. The Company enters into agreements with its broker-dealer clients pursuant to which the Company provides access to its platform through a non-exclusive and non-transferable license. Broker-dealer clients may pay an initial set-up fee, which is typically due and payable upon execution of a dealer agreement. The initial set-up fee, if any, varies by agreement. Revenue is recognized over the initial term of the agreement, which is generally two years. Initial set-up fees are reported in other income in the Consolidated Statements of Operations. Stock-Based Compensation The Company measures and recognizes compensation expense for all share-based payment awards based on their estimated fair values measured as of the grant date. These costs are recognized as an expense in the Consolidated Statements of Operations over the requisite service period, which is typically the vesting period, with an offsetting increase to additional paid-in capital. Income Taxes Income taxes are accounted for using the asset and liability method. Deferred income taxes reflect the net tax effects of temporary differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when such differences are expected to reverse. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance is recognized against deferred tax assets if it is more likely than not that such assets will not be realized in future years. The Company recognizes interest and penalties related to unrecognized tax benefits in general and administrative expenses in the Consolidated Statements of Operations. Business Combinations, Goodwill and Intangible Assets Business combinations are accounted for under the purchase method of accounting. The total cost of an acquisition is allocated to the underlying net assets based on their respective estimated fair values. The excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill. Determining the fair value of certain assets acquired and liabilities assumed is judgmental in nature and often involves the use of significant estimates and assumptions, including assumptions with respect to future cash flows, discount rates, growth rates and asset lives. The Company operates as a single reporting unit. Subsequent to an acquisition, goodwill no longer retains its identification with a particular acquisition, but instead becomes identifiable with the entire reporting unit. As a result, all of the fair value of the Company is available to support the value of goodwill. An impairment review of goodwill is performed on an annual basis, at year-end, or more frequently if circumstances change. Intangible assets with definite lives, including purchased technologies, customer relationships and other intangible assets, are amortized on a straight-line basis over their estimated useful lives, ranging from three to 15 years. Intangible assets are assessed for impairment when events or circumstances indicate the existence of a possible impairment. Earnings Per Share Basic earnings per share is computed by dividing the net income attributable to common stock by the weighted-average number of shares of common stock outstanding during the period. For purposes of computing diluted earnings per share, the weighted-average shares outstanding of common stock reflects the dilutive effect that could occur if convertible securities or other contracts to issue common stock were converted into or exercised for common stock. Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Out-of-Period Adjustments During the first quarter of 2016, the Company determined that it had incorrectly recorded deferred taxes for the cumulative translation adjustment (“CTA”) that arises from converting the local currency financial statements into U.S. dollars. Upon making a permanent reinvestment assertion on unremitted earnings from foreign subsidiaries effective January 1, 2013, the Company should have eliminated any deferred tax balances derived from the CTA balance. The Company also determined that gains and losses on the foreign currency forward contracts used to hedge the net investment in certain foreign subsidiaries were not appropriately considered as taxable income or expense in the consolidated tax returns. The Company assessed these errors and determined that they were not material to previous reporting periods. Therefore, the Company recorded these items as out-of-period adjustments in the three months ended March 31, 2016 by decreasing deferred tax assets by $3.1 million, decreasing other comprehensive income by $2.1 million and increasing prepaid expenses and other assets by $1.0 million in the Consolidated Statements of Financial Condition. Reclassifications Certain reclassifications have been made to the prior years’ Consolidated Financial Statements in order to conform to the current year presentation. Such reclassifications had no effect on previously reported net income. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”) requiring an entity to recognize revenue for the transfer of goods or services equal to the amount that it expects to be entitled to receive for those goods or services. The standard can be implemented using either a retrospective method or a cumulative-effect approach .In August 2015, the FASB deferred the effective date of the new revenue standard for periods beginning after December 15, 2016 to December 15, 2017, with early adoption permitted but not earlier than the original effective date. The ASU will be effective for the Company beginning January 1, 2018. While certain implementation issues are still pending resolution, including trade date versus settlement date recognition for broker dealers, the adoption of this accounting guidance is not expected to have a material effect on the Company’s Consolidated Financial Statements. In February 2016, the FASB issued ASU 2016-02, “Leases” (“ASU 2016-02”) requiring lessees to recognize lease assets and lease liabilities on the balance sheet for those leases previously classified as operating leases. ASU 2016-02 will be effective for the Company beginning January 1, 2019 and early adoption is permitted. The Company is currently evaluating the potential adoption impact and expects to recognize lease assets and lease liabilities in its Consolidated Statements of Financial Condition. The Company does not expect material changes to the recognition of operating lease expense in its Consolidated Statements of Operations. In March 2016, the FASB issued ASU 2016-09, “Improvements to Employee Share-Based Payment Accounting” (“ASU 2016-09”). ASU 2016-09 simplifies several aspects related to the accounting for share-based payment transactions, including the accounting for income taxes, statutory tax withholding requirements and classification on the statement of cash flows. The Company will adopt ASU 2016-09 beginning January 1, 2017 and, since the tax effects related to share-based payments will be recorded through the income tax provision, expects the new standard will have a significant impact and cause volatility in the Company’s net income, effective tax rate and diluted earnings per share. The volatility in future periods will depend on the Company’s stock price at the vest date for restricted stock awards or exercise date for stock options and the number of awards that vest or are exercised in each period. In November 2016, the FASB issued ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash” (“ASU 2016-18”) requiring amounts generally described as restricted cash or restricted cash equivalents be included with cash and cash equivalents when reconciling the total beginning and ending amounts for the periods shown on the statement of cash flows. ASU 2016-18 will be effective for the Company beginning January 1, 2018 and early adoption is permitted. The Company is in the process of determining the method of adoption and assessing the impact of ASU 2016-18 on the Company’s Consolidated Financial Statements.

Net Capital Requirements

Net Capital Requirements	12 Months Ended
	Dec. 31, 2016
Net Capital [Abstract]
Net Capital Requirements	3. Net Capital Requirements Certain U.S. subsidiaries of the Company are registered as a broker-dealer or swap execution facility and therefore are subject to the applicable rules and regulations of the Securities and Exchange Commission and the Commodity Futures Trading Commission. These rules contain minimum net capital requirements, as defined in the applicable regulations, and also may require a significant part of the registrants’ assets be kept in relatively liquid form. Certain of the Company’s foreign subsidiaries are regulated by the Financial Conduct Authority in the U.K. or Ontario Securities Commission in Canada and must maintain financial resources, as defined in the applicable regulations, in excess of the applicable financial resources requirement. As of December 31, 2016, each of the Company’s subsidiaries that are subject to these regulations had net capital or financial resources in excess of their minimum requirements. As of December 31, 2016, the Company’s subsidiaries maintained aggregate net capital and financial resources that was $126.0 million in excess of the required levels of $10.6 million. Each of the Company’s U.S. and foreign regulated subsidiaries are subject to local regulations which generally prohibit repayment of borrowings from the Company or affiliates, paying cash dividends, making loans to the Company or affiliates or otherwise entering into transactions that result in a significant reduction in regulatory net capital or financial resources without prior notification to or approval from such regulated entity’s principal regulator.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements The following table summarizes the valuation of the Company’s assets and liabilities measured at fair value as categorized based on the hierarchy described in Note 2. Level 1 Level 2 Level 3 Total As of December 31, 2016 (In thousands) Money market funds $ 58,573 $ — $ — $ 58,573 Securities available-for-sale Corporate debt — 118,870 — 118,870 Trading securities Corporate debt 74,207 74,207 Mutual funds held in rabbi trust — 1,327 — 1,327 Foreign currency forward position — (266 ) — (266 ) Total $ 58,573 $ 194,138 $ — $ 252,711 As of December 31, 2015 Money market funds $ 61,913 $ — $ — $ 61,913 Securities available-for-sale Corporate debt — 82,671 — 82,671 Municipal securities — 2,035 — 2,035 Foreign currency forward position — 354 — 354 Total $ 61,913 $ 85,060 $ — $ 146,973 Securities classified within Level 2 were valued using a market approach utilizing prices and other relevant information generated by market transactions involving comparable assets. The foreign currency forward contracts are classified within Level 2 as the valuation inputs are based on quoted market prices. The mutual funds held in a rabbi trust represent investments associated with the deferred cash incentive plan (see Note 14). There were no financial assets classified within Level 3 during the years ended December 31, 2016 and 2015. The Company enters into foreign currency forward contracts to hedge the net investment in the Company’s U.K. subsidiaries. The Company designates each foreign currency forward contract as a hedge and assesses the risk management objective and strategy, including identification of the hedging instrument, the hedged item and the risk exposure and how effectiveness is to be assessed prospectively and retrospectively. These hedges are for a one-month period and are used to limit exposure to foreign currency exchange rate fluctuations. The fair value of the asset is included in prepaid expenses and other assets and the fair value of the liability is included in accounts payable, accrued expenses and other liabilities in the Consolidated Statements of Financial Condition. Gains or losses on foreign currency forward contracts designated as hedges are included in accumulated other comprehensive loss in the Consolidated Statements of Financial Condition. A summary of the foreign currency forward position is as follows: As of December 31, 2016 2015 (In thousands) Notional value $ 66,972 $ 45,716 Fair value of notional 67,238 45,362 Fair value of the (liability) asset $ (266 ) $ 354 The following is a summary of the Company’s investments: Gross Gross Estimated Amortized unrealized unrealized fair cost gains losses value (In thousands) As of December 31, 2016 Securities available-for-sale Corporate debt $ 119,073 $ 13 $ (216 ) $ 118,870 Trading securities Corporate debt $ 74,394 $ 47 $ (234 ) $ 74,207 Mutual funds held in rabbi trust 1,212 115 — 1,327 Total trading securities $ 75,606 $ 162 $ (234 ) $ 75,534 Total investments $ 194,679 $ 175 $ (450 ) $ 194,404 As of December 31, 2015 Securities available-for-sale Corporate debt $ 82,937 $ 4 $ (270 ) $ 82,671 Municipal securities 2,035 — — 2,035 Total securities available-for-sale $ 84,972 $ 4 $ (270 ) $ 84,706 The following table summarizes the fair value of the investments based upon the contractual maturities: As of December 31, 2016 2015 (In thousands) Less than one year $ 117,904 $ 37,694 Due in 1 - 5 years 76,500 47,012 Total $ 194,404 $ 84,706 Proceeds from the sales and maturities of investments during the years ended December 31, 2016, 2015 and 2014 were $69.5 million, $35.2 million and $17.6 million, respectively. For the year ended December 31, 2016, net realized gains and net unrealized losses on corporate debt trading securities were $12 thousand and $0.2 million, respectively. The following table provides fair values and unrealized losses on investments and by the aging of the securities' continuous unrealized loss position as of December 31, 2016 and 2015 respectively: Less than Twelve Months Twelve Months or More Total Estimated Gross Estimated Gross Estimated Gross fair unrealized fair unrealized fair unrealized value losses value losses value losses (In thousands) As of December 31, 2016 Corporate debt $ 136,667 $ (449 ) $ 2,000 $ (1 ) $ 138,667 $ (450 ) As of December 31, 2015 Corporate debt $ 70,651 $ (270 ) $ — $ — $ 70,651 $ (270 )

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	5. Goodwill and Intangible Assets Goodwill and intangible assets with indefinite lives was $59.7 million as of both December 31, 2016 and 2015. Intangible assets that are subject to amortization, including the related accumulated amortization, are comprised of the following: December 31, 2016 December 31, 2015 Cost Accumulated Amortization Net Carrying Amount Cost Accumulated Amortization Net Carrying Amount (In thousands) Technology $ 5,770 $ (5,770 ) $ - $ 5,770 $ (5,492 ) $ 278 Customer relationships 5,628 (1,897 ) 3,731 5,668 (1,553 ) 4,115 Non-competition agreements 380 (380 ) - 380 (359 ) 21 Tradenames 370 (370 ) - 370 (353 ) 17 Total $ 12,148 $ (8,417 ) $ 3,731 $ 12,188 $ (7,757 ) $ 4,431 Amortization expense associated with identifiable intangible assets was $0.7 million, $2.3 million and $2.3 million, respectively, for the years ended December 31, 2016, 2015 and 2014. Estimated total amortization expense is

Capitalized Software, Furniture

Capitalized Software, Furniture, Equipment and Leasehold Improvements	12 Months Ended
	Dec. 31, 2016
Property Plant And Equipment [Abstract]
Capitalized Software, Furniture, Equipment and Leasehold Improvements	6. Capitalized Software, Furniture, Equipment and Leasehold Improvements Capitalized software development costs, furniture, equipment and leasehold improvements, net of accumulated depreciation and amortization, are comprised of the following: As of December 31, 2016 2015 (In thousands) Software development costs $ 71,551 $ 60,724 Computer hardware and related software 20,152 26,328 Office hardware 4,228 3,414 Furniture and fixtures 2,001 1,955 Leasehold improvements 8,351 8,457 106,283 100,878 Accumulated depreciation and amortization (75,179 ) (69,981 ) Total $ 31,104 $ 30,897 During the years ended December 31, 2016 and 2015, software development costs totaling $12.3 million and $10.6 million, respectively, were capitalized. Non-capitalized software costs and routine maintenance costs are expensed as incurred and are included in employee compensation and benefits and professional and consulting fees in the Consolidated Statements of Operations.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	7. Income Taxes The provision for income taxes consists of the following: Year Ended December 31, 2016 2015 2014 (In thousands) Current: Federal $ 45,455 $ 38,357 $ 31,700 State and local 7,087 7,180 6,505 Foreign 6,166 4,346 1,456 Total current provision 58,708 49,883 39,661 Deferred: Federal 5,884 1,492 3,583 State and local 1,141 299 530 Foreign (303 ) 189 (44 ) Total deferred provision 6,722 1,980 4,069 Provision for income taxes $ 65,430 $ 51,863 $ 43,730 Pre-tax income from U.S. operations was $161.9 million, $126.4 million and $112.5 million for the years ended December 31, 2016, 2015 and 2014, respectively. Pre-tax income from foreign operations was $29.7 million, $21.5 million and $6.0 million for the years ended December 31, 2016, 2015 and 2014, respectively. The difference between the Company’s reported provision for income taxes and the U.S. federal statutory rate of 35% is as follows: Year Ended December 31, 2016 2015 2014 U.S. federal tax at statutory rate 35.0 % 35.0 % 35.0 % State and local taxes - net of federal benefit 2.9 3.4 4.2 Credits and deductions related to research activities (1.3 ) (1.3 ) (1.7 ) Foreign rate differential benefit (2.3 ) (2.0 ) (0.6 ) Other, net (0.2 ) — — Provision for income taxes 34.1 % 35.1 % 36.9 % The following is a summary of the Company’s net deferred tax assets: As of December 31, 2016 2015 (In thousands) Deferred tax assets U.S. net operating loss carryforwards $ 1,909 $ 2,580 Capital loss carryforwards 7,235 7,294 Stock compensation expense 11,307 9,115 Other 1,468 3,745 Total deferred tax assets 21,919 22,734 Valuation allowance (7,235 ) (7,294 ) Net deferred tax assets 14,684 15,440 Deferred tax liabilities Depreciation and amortization (1,456 ) (1,953 ) Capitalized software development costs (4,923 ) (4,344 ) Intangible assets (1,037 ) (1,310 ) Deferred tax assets, net $ 7,268 $ 7,833 In 2001 and 2000, MarketAxess Holdings Inc. and MarketAxess Corporation had an ownership change within the meaning of Section 382 of the Internal Revenue Code. As of December 31, 2016, the Company had restricted U.S. federal net operating loss carryforwards of approximately $5.4 million, which begin to expire in 2021. The Company’s net operating loss carryforwards may be subject to additional annual limitations if there is a 50% or greater change in the Company’s ownership, as determined over a rolling three-year period. The ultimate realization of deferred income tax assets is dependent upon the generation of future taxable income during the periods in which the temporary differences become deductible. If it is not more likely than not that some portion or all of the gross deferred income tax assets will be realized in future years, a valuation allowance is recorded. As of December 31, 2016, the valuation allowance relates to certain capital loss carryforwards that are not expected to be realized. In October 2013, the Company recognized a $20.6 million capital loss on the sale of Greenline Financial Technologies, Inc. of which $1.2 million was carried back or otherwise utilized against current period capital gains. A full valuation allowance was provided against the remaining capital loss carryforward. A summary of the changes in the valuation allowance is as follows: Year Ended December 31, 2016 2015 2014 (In thousands) Valuation allowance at beginning of year $ 7,294 $ 7,428 $ 7,743 (Decrease) to valuation allowance attributable to: Current year income — — (101 ) State net operating loss — — (155 ) Other changes (59 ) (134 ) (59 ) Valuation allowance at end of year $ 7,235 $ 7,294 $ 7,428 The Company or one of its subsidiaries files U.S. federal, state and foreign income tax returns. Income tax returns for U.S. Federal (through 2013), New York City (through 2003) and state (through 2009) and Connecticut state (through 2003) have been audited. An examination of the Company’s New York State income tax returns for 2010 through 2012 is currently underway. The Company cannot estimate when the examination will conclude or the impact such examinations will have on the Company’s Consolidated Financial Statements, if any. A reconciliation of the unrecognized tax benefits is as follows: Year Ended December 31, 2016 2015 2014 (In thousands) Balance at beginning of year $ 265 $ 265 $ 265 Reductions for tax positions of prior years (236 ) — — Balance at end of year $ 29 $ 265 $ 265 The Company has determined that unremitted earnings of its foreign subsidiaries will be considered indefinitely reinvested outside of the United States. No provision has been made for income tax on approximately $36.9 million of undistributed earnings of foreign subsidiaries at December 31, 2016. If these earnings were repatriated to the United States or no longer determined to be indefinitely reinvested outside the United States, the deferred tax liability associated with such earnings would have been approximately $1.2 million.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Stockholders' Equity	8. Stockholders’ Equity Common Stock As of December 31, 2016 and 2015, the Company had 110,000,000 authorized shares of voting common stock and 10,000,000 authorized shares of non-voting common stock. Voting common stock entitles the holder to one vote per share of common stock held. The following is a summary of the change in the Company’s outstanding shares of voting common stock: Year Ended December 31, 2016 2015 2014 (In thousands) Outstanding shares of voting common stock at the beginning of year 37,409 37,319 37,729 Exercise of stock options 181 183 120 Issuance of restricted stock, net of shares withheld for tax payments and cancellations 104 178 116 Repurchases (150 ) (271 ) (646 ) Outstanding shares of voting common stock at the end of year 37,544 37,409 37,319 In January 2014, the Board of Directors of the Company authorized a two-year share repurchase program for up to $35.0 million of the Company’s common stock, and in July 2014, the Board of Directors increased the authorization by an additional $65.0 million. A total of 917,354 shares were repurchased under this program. Dividends During 2016, 2015 and 2014, we paid quarterly cash dividends of $0.26 per share, $0.20 per share and $0.16 per share, respectively.

Stock-Based Compensation Plans

Stock-Based Compensation Plans	12 Months Ended
	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation Plans	9. Stock-Based Compensation Plans The Company has a stock incentive plan which provides for the grant of stock options, stock appreciation rights, restricted stock, performance shares, performance units, or other stock-based awards as incentives and rewards to encourage employees, consultants and non-employee directors to participate in the long-term success of the Company. As of December 31, 2016, there were 360,035 shares available for grant under the stock incentive plan. Total stock-based compensation expense was as follows: Year Ended December 31, 2016 2015 2014 (In thousands) Employee: Restricted stock and performance shares $ 12,459 $ 10,792 $ 8,193 Stock options 1,143 826 676 13,602 11,618 8,869 Non-employee directors: Restricted stock 909 901 900 Total stock-based compensation $ 14,511 $ 12,519 $ 9,769 The Company records stock-based compensation expense for employees in employee compensation and benefits and for non-employee directors in general and administrative expenses in the Consolidated Statements of Operations. Stock Options The exercise price of each option granted is equal to the market price of the Company’s common stock on the date of grant. Generally, option grants have provided for vesting over a three or five-year period. Options generally expire in six or ten years from the date of grant. The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model. The determination of fair value of share-based payment awards on the date of grant using an option-pricing model is affected by the Company’s stock price as well as assumptions regarding a number of highly complex and subjective variables, including the expected stock price volatility over the term of the awards, the risk-free interest rate, the expected dividend yield rate and the expected term. Expected volatilities are based on historical volatility of the Company’s stock. The risk-free interest rate is based on U.S. Treasury securities with a maturity value approximating the expected term of the option. The dividend yield rate is based on the expected annual dividends to be paid divided by the expected stock price. The expected term represents the period of time that options granted are expected to be outstanding based on actual and projected employee stock option exercise behavior. The weighted-average fair value for options granted during 2016, 2015 and 2014 was $32.24, $36.46 and $19.25, respectively. The following table represents the assumptions used for the Black-Scholes option-pricing model to determine the per share weighted-average fair value for options granted for the three years ended December 31, 2016: 2016 2015 2014 Expected life (years) 6.0 7.0 5.0 Risk-free interest rate 1.9 % 1.9 % 1.7 % Expected volatility 33.0 % 56.7 % 35.5 % Expected dividend yield 1.0 % 1.1 % 1.0 % In addition to the option grants above, the Company granted 119,981 stock options to the Company’s Chief Executive Officer in January 2015 which expire in 5.5 years from the grant date. Subject to the Chief Executive Officer’s continued employment with the Company through the applicable vesting date, one-third of the options under the option award will vest and become exercisable on each of January 15, 2018, 2019 and 2020. The fair value of the option award as of the date of the grant was $2.0 million as determined by an independent third party using a Monte Carlo simulation model. Key assumptions used for the Monte Carlo pricing model included an exercise price of $88.25 (125% of the market price on the date of the grant), a risk free interest rate of 1.4%, volatility of 27.3% and a dividend yield of 0.9%. The following table reports stock option activity during the three years ended December 31, 2016 and the intrinsic value as of December 31, 2016: Weighted- Remaining Number of Average Contractual Shares Exercise Price ($) Term Intrinsic Value ($) (In thousands) Outstanding at December 31, 2013 1,220,449 $ 15.01 Granted 382 63.07 Canceled (41,071 ) 41.47 Exercised (165,340 ) 15.85 Outstanding at December 31, 2014 1,014,420 13.81 Granted 120,650 88.15 Canceled — — Exercised (196,034 ) 11.60 Outstanding at December 31, 2015 939,036 23.83 Granted 112,988 102.40 Canceled (874 ) 101.77 Exercised (195,410 ) 12.35 $ 21,929 Outstanding at December 31, 2016 855,740 36.80 2.8 94,235 Exercisable at December 31, 2016 623,076 14.98 2.2 82,208 The intrinsic value is the amount by which the closing price of the Company’s common stock on December 31, 2016 of $146.92 or the price on the day of exercise exceeds the exercise price of the stock options multiplied by the number of shares. As of December 31, 2016, there was $4.1 million of total unrecognized compensation cost related to non-vested stock options. That cost is expected to be recognized over a weighted-average period of 3.2 years. Restricted Stock and Performance Shares Restricted stock generally vests over a three or five-year period. Compensation expense is measured at the grant date and recognized ratably over the vesting period. Annual performance share awards are granted to certain officers and senior managers. Each performance share award is earned or forfeited based on the level of achievement by the Company of pre-tax operating income, as defined. The pay-out ranges from zero to 150% of the performance share award. For each performance share earned, a participant is awarded an equal number of shares of restricted stock. Any restricted stock awarded to a participant vests and ceases to be restricted stock in two equal installments on each of the second and third anniversaries of the date of grant of the applicable performance share award. Compensation expense for performance shares is measured at the grant date and recognized on a graded basis over the vesting period. Performance year 2016 2015 2014 Share pay-out at plan 15,390 28,520 29,678 Actual share pay-out in following year 21,423 37,696 25,228 Weighted average fair value per share on grant date $ 101.77 $ 70.60 $ 63.07 In January 2016, the Company granted 33,509 multi-year performance shares to certain officers and senior managers. Each performance share award is earned or forfeited based on the level of achievement by the Company of aggregate operating income over the three year period beginning January 1, 2016. The pay-out ranges from zero to 150% of the performance award value. Any restricted stock awarded will vest 50% on January 31, 2020 and 50% on January 31, 2021. The fair value per share of the awards on the grant date was $103.30. In addition to the grants above, the Company granted 116,659 performance shares to the Company’s Chief Executive Officer in January 2015. The performance share award provided that the number of performance shares earned by the Chief Executive Officer would be based on the Company’s achievement of certain performance levels. Upon achievement of the performance levels, a total of 92,419 shares and . The following table reports restricted stock and performance share activity during the three years ended December 31, 2016: Weighted-Average Number of Grant Date Fair Restricted Shares Value Outstanding at December 31, 2013 569,734 $ 31.86 Granted 149,349 Performance share pay-out 46,340 Canceled (43,185 ) Vested (286,249 ) Outstanding at December 31, 2014 435,989 $ 41.83 Granted 117,668 Performance share pay-out 117,647 Canceled (3,845 ) Vested (235,321 ) Outstanding at December 31, 2015 432,138 $ 56.24 Granted 95,419 Performance share pay-out 61,936 Canceled (12,786 ) Vested (192,729 ) Outstanding at December 31, 2016 383,978 $ 71.50 As of December 31, 2016, there was $18.7 million of total unrecognized compensation expense related to non-vested restricted stock and performance shares. That cost is expected to be recognized over a weighted-average period of 2.0 years. Employee Stock Purchase Plan During 2015, the Company established a non-qualified employee stock purchase plan for non-executive employees. Under the plan, participants are granted the right to purchase shares of common stock based on the fair market value on the last day of the six-month offering period. On the purchase date, the Company will grant to the participants a number of shares of common stock equal to 20% of the aggregate shares purchased by the participant. These matching shares vest over a one-year period.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Earnings Per Share	10. Earnings Per Share The following table sets forth the computation of basic and diluted earnings per common share: Year Ended December 31, 2016 2015 2014 (In thousands, except per share amounts) Net income $ 126,172 $ 96,037 $ 74,806 Basic weighted average shares outstanding 36,844 36,690 36,930 Dilutive effect of stock options and restricted stock 894 947 959 Diluted weighted average shares outstanding 37,738 37,637 37,889 Basic earnings per share $ 3.42 $ 2.62 $ 2.03 Diluted earnings per share $ 3.34 $ 2.55 $ 1.97 Stock options and restricted stock totaling 84,052 shares, 128,383 shares and 66,637 shares for the years ended December 31, 2016, 2015 and 2014, respectively, were excluded from the computation of diluted earnings per share because their effect would have been antidilutive. The computation of diluted shares can vary among periods due, in part, to the change in the average price of the Company’s common stock.

Credit Agreement

Credit Agreement	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Credit Agreement	11. Credit Agreement In January 2013, the Company entered into a three-year credit agreement that provided for revolving loans and letters of credit up to an aggregate of $50.0 million. In October 2015, the company entered into an amended and restated credit agreement (the “Credit Agreement”) increasing the borrowing capacity to an aggregate of $100.0 million, including a $5.0 million sub-limit for standby letters of credit. The Credit Agreement will mature in October 2017. As of December 31, 2016, the Company had $0.9 million in letters of credit outstanding and $99.1 million in available borrowing capacity under the Credit Agreement. Subject to satisfaction of certain specified conditions, the Company is permitted to upsize the borrowing capacity under the Credit Agreement by an additional $50.0 million. Borrowings under the Credit Agreement will bear interest at a rate per annum equal to either of the following, as designated by the Company for each borrowing: (A) the sum of (i) the greatest of (a) the prime rate, as defined, (b) the federal funds effective rate plus 0.50% and (c) one month adjusted LIBOR plus 1.00% plus (ii) 0.50% or (B) the sum of (i) adjusted LIBOR plus (ii) 1.50%. Default interest is 2.00% per annum in excess of the rate otherwise applicable in the case of any overdue principal or any other overdue amount. The Company is also required to pay a commitment fee to the lenders under the Credit Agreement in respect of unutilized revolving loan commitments at a rate of 0.40% per annum. The Company’s existing and future domestic subsidiaries (other than any regulated subsidiary) have guaranteed the Company’s obligations under the Credit Agreement. Subject to customary exceptions and exclusions, the Company’s borrowings under the Credit Agreement are collateralized by first priority pledges (subject to permitted liens) of substantially all of the Company’s personal property assets and the personal property assets of the Company’s domestic subsidiaries that have guaranteed the Credit Agreement, including the equity interests of the Company’s domestic subsidiaries and the equity interests of certain of the Company’s foreign subsidiaries (limited, in the case of the voting equity interests of the foreign subsidiaries, to a pledge of 65% of those equity interests). The Credit Agreement requires that the Company’s consolidated total leverage ratio tested on the last day of each fiscal quarter not exceed 2.5 to 1.0 and a consolidated interest coverage ratio tested on the last day of each fiscal quarter not be less than 3.5 to 1.0. The Credit Agreement also requires that the Company’s trailing twelve month adjusted EBITDA tested on the last day of each fiscal quarter not be less than $80 million. The Company was in compliance with all applicable covenants at December 31, 2016 and 2015. If an event of default occurs, including failure to pay principal or interest due on the loan balance, a voluntary or involuntary proceeding seeking liquidation, change in control of the Company, or one or more material judgments against the Company in excess of $10.0 million, the lenders would be entitled to accelerate the borrowings under the Credit Agreement and take various other actions, including all actions permitted to be taken by a secured creditor. If certain bankruptcy events of default occur, the borrowings under the Credit Agreement will automatically accelerate.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	12. Commitments and Contingencies Lease Commitments The Company leases office space under non-cancelable lease agreements expiring at various dates through 2033. Office space leases are subject to escalation based on certain costs incurred by the landlord. Minimum rental commitments as of December 31, 2016 under such operating leases were as follows (in thousands): 2017 $ 4,438 2018 4,296 2019 9,205 2020 10,492 2021 10,079 2022 and thereafter 107,815 $ 146,325 Rental expense for the years ended December 31, 2016, 2015 and 2014 was $4.0 million, $4.1 million and $3.8 million, respectively, and is included in occupancy expense in the Consolidated Statements of Operations. Rental expense has been recorded based on the total minimum lease payments after giving effect to rent abatement and concessions, which are being amortized on a straight-line basis over the life of the lease. The Company is contingently obligated for standby letters of credit amounting to $0.9 million that were issued to landlords for office space. During 2016, the Company entered into non-cancelable lease agreements for approximately 108,000 square feet of office space with commencement dates on or after December 1, 2016 that expire through December 31, 2033. The aggregate minimum rental commitment under such leases is $127.4 million. The Company has assigned a lease agreement on a leased property to a third party and is contingently liable should the assignee default on future lease obligations through the November 2020 lease termination date. The aggregate amount of the future lease obligation under this arrangement is $1.0 million as of December 31, 2016. Legal In the normal course of business, the Company and its subsidiaries included in the consolidated financial statements may be involved in various lawsuits, proceedings and regulatory examinations. The Company assesses its liabilities and contingencies in connection with outstanding legal proceedings, if any, utilizing the latest information available. For matters where it is probable that the Company will incur a material loss and the amount can be reasonably estimated, the Company would establish an accrual for the loss. Once established, the accrual would be adjusted to reflect any relevant developments. When a loss contingency is not both probable and estimable, the Company does not establish an accrual. Based on currently available information, the outcome of the Company’s outstanding matters is not expected to have a material adverse impact on the Company’s financial position. It is not presently possible to determine the ultimate exposure to these matters and there is no assurance that the resolution of the outstanding matters will not significantly exceed any reserves accrued by the Company. Other The Company, through two regulated subsidiaries, executes certain bond transactions between and among institutional investor and broker-dealer clients on a matched principal basis by serving as counterparty to both the buyer and the seller in trades which settle through third-party clearing brokers. Settlement typically occurs within one to three trading days after the trade date. Cash settlement of the transaction occurs upon receipt or delivery of the underlying instrument that was traded. For the years ended December 31, 2016, 2015 and 2014, revenues from matched principal trading were approximately $37.7 million, $16.9 million and $7.4 million, respectively. Under securities clearing agreements with third party clearing brokers, the Company maintains collateral deposits with each clearing broker in the form of cash. As of December 31, 2016, the amount of the collateral deposits included in prepaid expenses and other assets in the Consolidated Statements of Financial Condition was $1.1 million. For the years ended December 31, 2016, 2015 and 2014, clearing expenses associated with matched principal transactions were $6.1 million, $3.3 million and $1.3 million, respectively, and are classified under general and administrative expense on the Consolidated Statements of Operations. The Company is exposed to credit risk in the event a counterparty does not fulfill its obligation to complete a transaction or if there is a miscommunication or other error in executing a matched principal transaction. Pursuant to the terms of the securities clearing agreements, each clearing broker has the right to charge the Company for any losses they suffer resulting from a counterparty’s failure on any of the Company’s trades. The Company did not record any liabilities or losses with regard to this right for the years ended December 31, 2016 and 2015. In the normal course of business, the Company enters into contracts that contain a variety of representations, warranties and general indemnifications. The Company’s maximum exposure under these arrangements is unknown, as this would involve future claims that may be made against the Company that have not yet occurred. However, based on experience, the Company expects the risk of loss to be remote.

Segment and Geographic Informat

Segment and Geographic Information	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Segment and Geographic Information	13. Segment and Geographic Information The Company operates an electronic multi-party platform for the trading of fixed-income securities and provides related data, analytics, compliance tools and post-trade services. The Company’s operations constitute a single business segment because of the highly integrated nature of these product and services, of the financial markets in which the Company competes and of the Company’s worldwide business activities. The Company believes that results by geographic region or client sector are not necessarily meaningful in understanding its business. For the years ended December 31, 2016, 2015 and 2014, the U.K. was the only individual foreign country in which the Company had a subsidiary that accounted for 10% or more of the total revenues or total long-lived assets. Revenues and long-lived assets are attributed to geographic area based on the location of the particular subsidiary. Long-lived assets are defined as furniture, equipment, leasehold improvements and capitalized software Year Ended December 31, 2016 2015 2014 (In thousands) Revenues United States $ 314,343 $ 262,558 $ 223,741 United Kingdom 54,015 39,338 38,189 Other 1,561 1,202 844 Total $ 369,919 $ 303,098 $ 262,774 As of December 31, 2016 2015 (In thousands) Long-lived assets, as defined United States $ 23,370 $ 21,968 United Kingdom 7,713 8,910 Other 21 19 Total $ 31,104 $ 30,897

Retirement and Deferred Compens

Retirement and Deferred Compensation Plans	12 Months Ended
	Dec. 31, 2016
Compensation And Retirement Disclosure [Abstract]
Retirement and Deferred Compensation Plans	14. Retirement and Deferred Compensation Plans The Company, through its U.S. and U.K. subsidiaries, offers its employees the opportunity to invest in defined contribution plans. For the years ended December 31, 2016, 2015 and 2014, the Company contributed $1.9 million, $1.9 million and $1.8 million, respectively, to the plans. In 2015, the Company adopted a non-qualified deferred cash incentive plan for certain officers and other employees. Under the plan, eligible employees may defer up to 100% of their annual cash incentive pay. The Company has elected to fund its deferred compensation obligations through a rabbi trust. The rabbi trust is subject to creditor claims in the event of insolvency but such assets are not available for general corporate purposes. Assets held in the rabbi trust are invested in mutual funds, as selected by the participants, which are designated as trading securities and carried at fair value. The initial deferrals occurred in January 2016 and as of December 31, 2016, the fair value of the mutual fund investments and deferred compensation obligation was $1.3 million. Changes in the fair value of securities held in the rabbi trust are recognized as trading gains and losses and included in other revenues and offsetting increases or decreases in the deferred compensation obligation will be recorded in employee compensation and benefits. For the year ended December 31, 2016, the trading gains and compensation expense were each $0.2 million.

Customer Concentration

Customer Concentration	12 Months Ended
	Dec. 31, 2016
Risks And Uncertainties [Abstract]
Customer Concentration	15. Customer Concentration During the years ended December 31, 2016, 2015 and 2014, no single client accounted for more than 10% of total revenue. One institutional investor client accounted for approximately 14.2%, 15.3% and 14.0% of trading volumes during the years ended December 31, 2016, 2015 and 2014, respectively. As of December 31, 2016, investment funds managed by this institutional investor client beneficially owned approximately 7.6% of the outstanding shares of the Company’s common stock, primarily through passive index and ETF funds.

Significant Accounting Polici24

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany transactions and balances have been eliminated.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents includes cash and money market instruments that are primarily maintained at one major global bank. Given this concentration, the Company is exposed to certain credit risk in relation to its deposits at this bank. The Company defines cash equivalents as short-term interest-bearing investments with maturities at the time of purchase of three months or less.
Investments	Investments The Company determines the appropriate classification of securities at the time of purchase which are recorded in the Consolidated Statements of Financial Condition on the trade date. Securities are classified as available-for-sale or trading. The Company’s available-for-sale investments are comprised of municipal bonds and investment grade corporate debt securities. Available-for-sale investments are carried at fair value with the unrealized gains or losses reported in accumulated other comprehensive loss in the Consolidated Statements of Financial Condition. Trading investments primarily include investment grade corporate debt securities and are carried at fair value, with realized and unrealized gains or losses included in other income in the Consolidated Statements of Operations. The Company assesses whether an other-than-temporary impairment loss on the available-for-sale investments has occurred due to declines in fair value or other market conditions. The portion of an other-than-temporary impairment related to credit loss is recorded as a charge in the Consolidated Statements of Operations. The remainder is recognized in accumulated other comprehensive loss if the Company does not intend to sell the security and it is more likely than not that the Company will not be required to sell the security prior to recovery. No charges for other-than-temporary losses were recorded during the years ended December 31, 2016, 2015 and 2014.
Fair Value Financial Instruments	Fair Value Financial Instruments Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” A three-tiered hierarchy for determining fair value has been established that prioritizes inputs to valuation techniques used in fair value calculations. The three levels of inputs are defined as Level 1 (unadjusted quoted prices for identical assets or liabilities in active markets), Level 2 (inputs that are observable in the marketplace other than those inputs classified in Level 1) and Level 3 (inputs that are unobservable in the marketplace). The Company’s financial assets and liabilities measured at fair value on a recurring basis consist of its money market funds, securities available-for-sale, trading securities and foreign currency forward contracts. All other financial instruments are short-term in nature and the carrying amount is reported on the Consolidated Statements of Financial Condition at approximate fair value.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts All accounts receivable have contractual maturities of less than one year and are derived from trading-related fees and commissions and revenues from products and services. The Company continually monitors collections and payments from its customers and maintains an allowance for doubtful accounts. The allowance for doubtful accounts is based upon the historical collection experience and specific collection issues that have been identified. Additions to the allowance for doubtful accounts are charged to bad debt expense, which is included in general and administrative expense in the Company’s Consolidated Statements of Operations. The allowance for doubtful accounts was $0.1 million, $0.1 million and $0.0 million as of December 31, 2016, 2015 and 2014, respectively. The provision for bad debts was $0.2 million, $0.2 million and $0.1 million for the years ended December 31, 2016, 2015 and 2014, respectively. Write-offs and other charges against the allowance for doubtful accounts were $0.1 million, $0.1 million and $0.0 million for the years ended December 31, 2016, 2015 and 2014, respectively.
Depreciation and Amortization	Depreciation and Amortization Fixed assets are carried at cost less accumulated depreciation. The Company uses the straight-line method of depreciation over three to seven years. The Company amortizes leasehold improvements on a straight-line basis over the lesser of the life of the improvement or the remaining term of the lease.
Software Development Costs	Software Development Costs The Company capitalizes certain costs associated with the development of internal use software, including among other items, employee compensation and related benefits and third party consulting costs at the point at which the conceptual formulation, design and testing of possible software project alternatives have been completed. Once the product is ready for its intended use, such costs are amortized on a straight-line basis over three years. The Company reviews the amounts capitalized for impairment whenever events or changes in circumstances indicate that the carrying amounts of the assets may not be recoverable.
Cash Provided as Collateral	Cash Provided as Collateral Cash is provided as collateral for broker-dealer clearing accounts. Cash provided as collateral is included in prepaid expenses and other assets in the Consolidated Statements of Financial Condition.
Foreign Currency Translation and Forward Contracts	Foreign Currency Translation and Forward Contracts Assets and liabilities denominated in foreign currencies are translated using exchange rates at the end of the period; revenues and expenses are translated at average monthly rates. Gains and losses on foreign currency translation are a component of accumulated other comprehensive loss in the Consolidated Statements of Financial Condition. Transaction gains and losses are recorded in general and administrative expense in the Consolidated Statements of Operations. The Company enters into foreign currency forward contracts to hedge its net investment in its U.K. subsidiaries. Gains and losses on these transactions are included in accumulated other comprehensive loss in the Consolidated Statements of Financial Condition.
Revenue Recognition	Revenue Recognition The majority of the Company’s revenues are derived from commissions for trades executed on its platform and distribution fees that are billed to its broker-dealer clients on a monthly basis. The Company also derives revenues from information and post-trade services, technology products and services, investment income and other income. Commission revenue. Commissions are generally calculated as a percentage of the notional dollar volume of bonds traded on the platform and vary based on the type, size, yield and maturity of the bond traded. Under the Company’s transaction fee plans, bonds that are more actively traded or that have shorter maturities are generally charged lower commissions, while bonds that are less actively traded or that have longer maturities generally command higher commissions. For trades that the Company executes between and among institutional investor and broker-dealer clients on a matched principal basis by serving as counterparty to both the buyer and the seller, the Company earns the commission through the difference in price between the two matched principal trades. Fee programs for certain products include distribution fees which are recognized monthly. Information and post-trade services. The Company generates revenue from information services provided to our broker-dealer clients, institutional investor clients and data-only subscribers. Information services are invoiced monthly, quarterly or annually. When billed in advance, revenues are deferred and recognized monthly on a straight-line basis. The Company also generates revenue from regulatory transaction reporting and trade matching services. Revenue is recognized in the period the services are provided. Technology products and services. The Company generates revenues from professional consulting services, technology software licenses and maintenance and support services. Revenue from professional consulting services is recognized as services are performed and software license subscription revenue and maintenance and support services are recognized ratably over the contract period. Technology products and services revenue is reported in other income in the Consolidated Statements of Operations. Initial set-up fees. The Company enters into agreements with its broker-dealer clients pursuant to which the Company provides access to its platform through a non-exclusive and non-transferable license. Broker-dealer clients may pay an initial set-up fee, which is typically due and payable upon execution of a dealer agreement. The initial set-up fee, if any, varies by agreement. Revenue is recognized over the initial term of the agreement, which is generally two years. Initial set-up fees are reported in other income in the Consolidated Statements of Operations.
Stock-Based Compensation	Stock-Based Compensation The Company measures and recognizes compensation expense for all share-based payment awards based on their estimated fair values measured as of the grant date. These costs are recognized as an expense in the Consolidated Statements of Operations over the requisite service period, which is typically the vesting period, with an offsetting increase to additional paid-in capital.
Income Taxes	Income Taxes Income taxes are accounted for using the asset and liability method. Deferred income taxes reflect the net tax effects of temporary differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when such differences are expected to reverse. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance is recognized against deferred tax assets if it is more likely than not that such assets will not be realized in future years. The Company recognizes interest and penalties related to unrecognized tax benefits in general and administrative expenses in the Consolidated Statements of Operations.
Business Combinations, Goodwill and Intangible Assets	Business Combinations, Goodwill and Intangible Assets Business combinations are accounted for under the purchase method of accounting. The total cost of an acquisition is allocated to the underlying net assets based on their respective estimated fair values. The excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill. Determining the fair value of certain assets acquired and liabilities assumed is judgmental in nature and often involves the use of significant estimates and assumptions, including assumptions with respect to future cash flows, discount rates, growth rates and asset lives. The Company operates as a single reporting unit. Subsequent to an acquisition, goodwill no longer retains its identification with a particular acquisition, but instead becomes identifiable with the entire reporting unit. As a result, all of the fair value of the Company is available to support the value of goodwill. An impairment review of goodwill is performed on an annual basis, at year-end, or more frequently if circumstances change. Intangible assets with definite lives, including purchased technologies, customer relationships and other intangible assets, are amortized on a straight-line basis over their estimated useful lives, ranging from three to 15 years. Intangible assets are assessed for impairment when events or circumstances indicate the existence of a possible impairment.
Earnings Per Share	Earnings Per Share Basic earnings per share is computed by dividing the net income attributable to common stock by the weighted-average number of shares of common stock outstanding during the period. For purposes of computing diluted earnings per share, the weighted-average shares outstanding of common stock reflects the dilutive effect that could occur if convertible securities or other contracts to issue common stock were converted into or exercised for common stock.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Out-of-Period Adjustments	Out-of-Period Adjustments During the first quarter of 2016, the Company determined that it had incorrectly recorded deferred taxes for the cumulative translation adjustment (“CTA”) that arises from converting the local currency financial statements into U.S. dollars. Upon making a permanent reinvestment assertion on unremitted earnings from foreign subsidiaries effective January 1, 2013, the Company should have eliminated any deferred tax balances derived from the CTA balance. The Company also determined that gains and losses on the foreign currency forward contracts used to hedge the net investment in certain foreign subsidiaries were not appropriately considered as taxable income or expense in the consolidated tax returns. The Company assessed these errors and determined that they were not material to previous reporting periods. Therefore, the Company recorded these items as out-of-period adjustments in the three months ended March 31, 2016 by decreasing deferred tax assets by $3.1 million, decreasing other comprehensive income by $2.1 million and increasing prepaid expenses and other assets by $1.0 million in the Consolidated Statements of Financial Condition.
Reclassifications	Reclassifications Certain reclassifications have been made to the prior years’ Consolidated Financial Statements in order to conform to the current year presentation. Such reclassifications had no effect on previously reported net income.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”) requiring an entity to recognize revenue for the transfer of goods or services equal to the amount that it expects to be entitled to receive for those goods or services. The standard can be implemented using either a retrospective method or a cumulative-effect approach .In August 2015, the FASB deferred the effective date of the new revenue standard for periods beginning after December 15, 2016 to December 15, 2017, with early adoption permitted but not earlier than the original effective date. The ASU will be effective for the Company beginning January 1, 2018. While certain implementation issues are still pending resolution, including trade date versus settlement date recognition for broker dealers, the adoption of this accounting guidance is not expected to have a material effect on the Company’s Consolidated Financial Statements. In February 2016, the FASB issued ASU 2016-02, “Leases” (“ASU 2016-02”) requiring lessees to recognize lease assets and lease liabilities on the balance sheet for those leases previously classified as operating leases. ASU 2016-02 will be effective for the Company beginning January 1, 2019 and early adoption is permitted. The Company is currently evaluating the potential adoption impact and expects to recognize lease assets and lease liabilities in its Consolidated Statements of Financial Condition. The Company does not expect material changes to the recognition of operating lease expense in its Consolidated Statements of Operations. In March 2016, the FASB issued ASU 2016-09, “Improvements to Employee Share-Based Payment Accounting” (“ASU 2016-09”). ASU 2016-09 simplifies several aspects related to the accounting for share-based payment transactions, including the accounting for income taxes, statutory tax withholding requirements and classification on the statement of cash flows. The Company will adopt ASU 2016-09 beginning January 1, 2017 and, since the tax effects related to share-based payments will be recorded through the income tax provision, expects the new standard will have a significant impact and cause volatility in the Company’s net income, effective tax rate and diluted earnings per share. The volatility in future periods will depend on the Company’s stock price at the vest date for restricted stock awards or exercise date for stock options and the number of awards that vest or are exercised in each period. In November 2016, the FASB issued ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash” (“ASU 2016-18”) requiring amounts generally described as restricted cash or restricted cash equivalents be included with cash and cash equivalents when reconciling the total beginning and ending amounts for the periods shown on the statement of cash flows. ASU 2016-18 will be effective for the Company beginning January 1, 2018 and early adoption is permitted. The Company is in the process of determining the method of adoption and assessing the impact of ASU 2016-18 on the Company’s Consolidated Financial Statements.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Valuation of Company's Assets and Liabilities Measured at Fair Value	The following table summarizes the valuation of the Company’s assets and liabilities measured at fair value as categorized based on the hierarchy described in Note 2. Level 1 Level 2 Level 3 Total As of December 31, 2016 (In thousands) Money market funds $ 58,573 $ — $ — $ 58,573 Securities available-for-sale Corporate debt — 118,870 — 118,870 Trading securities Corporate debt 74,207 74,207 Mutual funds held in rabbi trust — 1,327 — 1,327 Foreign currency forward position — (266 ) — (266 ) Total $ 58,573 $ 194,138 $ — $ 252,711 As of December 31, 2015 Money market funds $ 61,913 $ — $ — $ 61,913 Securities available-for-sale Corporate debt — 82,671 — 82,671 Municipal securities — 2,035 — 2,035 Foreign currency forward position — 354 — 354 Total $ 61,913 $ 85,060 $ — $ 146,973
Summary of Foreign Currency Forward Contracts	A summary of the foreign currency forward position is as follows: As of December 31, 2016 2015 (In thousands) Notional value $ 66,972 $ 45,716 Fair value of notional 67,238 45,362 Fair value of the (liability) asset $ (266 ) $ 354
Summary of Company's Investments	The following is a summary of the Company’s investments: Gross Gross Estimated Amortized unrealized unrealized fair cost gains losses value (In thousands) As of December 31, 2016 Securities available-for-sale Corporate debt $ 119,073 $ 13 $ (216 ) $ 118,870 Trading securities Corporate debt $ 74,394 $ 47 $ (234 ) $ 74,207 Mutual funds held in rabbi trust 1,212 115 — 1,327 Total trading securities $ 75,606 $ 162 $ (234 ) $ 75,534 Total investments $ 194,679 $ 175 $ (450 ) $ 194,404 As of December 31, 2015 Securities available-for-sale Corporate debt $ 82,937 $ 4 $ (270 ) $ 82,671 Municipal securities 2,035 — — 2,035 Total securities available-for-sale $ 84,972 $ 4 $ (270 ) $ 84,706
Summary of Fair Value of Investments Based upon Contractual Maturities	The following table summarizes the fair value of the investments based upon the contractual maturities: As of December 31, 2016 2015 (In thousands) Less than one year $ 117,904 $ 37,694 Due in 1 - 5 years 76,500 47,012 Total $ 194,404 $ 84,706
Fair Values and Unrealized Losses on Investments	The following table provides fair values and unrealized losses on investments and by the aging of the securities' continuous unrealized loss position as of December 31, 2016 and 2015 respectively: Less than Twelve Months Twelve Months or More Total Estimated Gross Estimated Gross Estimated Gross fair unrealized fair unrealized fair unrealized value losses value losses value losses (In thousands) As of December 31, 2016 Corporate debt $ 136,667 $ (449 ) $ 2,000 $ (1 ) $ 138,667 $ (450 ) As of December 31, 2015 Corporate debt $ 70,651 $ (270 ) $ — $ — $ 70,651 $ (270 )

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Company's Intangible Assets	Goodwill and intangible assets with indefinite lives was $59.7 million as of both December 31, 2016 and 2015. Intangible assets that are subject to amortization, including the related accumulated amortization, are comprised of the following: December 31, 2016 December 31, 2015 Cost Accumulated Amortization Net Carrying Amount Cost Accumulated Amortization Net Carrying Amount (In thousands) Technology $ 5,770 $ (5,770 ) $ - $ 5,770 $ (5,492 ) $ 278 Customer relationships 5,628 (1,897 ) 3,731 5,668 (1,553 ) 4,115 Non-competition agreements 380 (380 ) - 380 (359 ) 21 Tradenames 370 (370 ) - 370 (353 ) 17 Total $ 12,148 $ (8,417 ) $ 3,731 $ 12,188 $ (7,757 ) $ 4,431

Capitalized Software, Furnitu27

Capitalized Software, Furniture, Equipment and Leasehold Improvements (Tables)	12 Months Ended
	Dec. 31, 2016
Property Plant And Equipment [Abstract]
Capitalized Software Development Costs, Furniture, Equipment and Leasehold Improvements, Net of Accumulated Depreciation and Amortization	Capitalized software development costs, furniture, equipment and leasehold improvements, net of accumulated depreciation and amortization, are comprised of the following: As of December 31, 2016 2015 (In thousands) Software development costs $ 71,551 $ 60,724 Computer hardware and related software 20,152 26,328 Office hardware 4,228 3,414 Furniture and fixtures 2,001 1,955 Leasehold improvements 8,351 8,457 106,283 100,878 Accumulated depreciation and amortization (75,179 ) (69,981 ) Total $ 31,104 $ 30,897

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Schedule of Provision for Income Taxes	The provision for income taxes consists of the following: Year Ended December 31, 2016 2015 2014 (In thousands) Current: Federal $ 45,455 $ 38,357 $ 31,700 State and local 7,087 7,180 6,505 Foreign 6,166 4,346 1,456 Total current provision 58,708 49,883 39,661 Deferred: Federal 5,884 1,492 3,583 State and local 1,141 299 530 Foreign (303 ) 189 (44 ) Total deferred provision 6,722 1,980 4,069 Provision for income taxes $ 65,430 $ 51,863 $ 43,730
Difference Between the Company's Reported Provision for Income Taxes and the U.S. Federal Statutory Rate	The difference between the Company’s reported provision for income taxes and the U.S. federal statutory rate of 35% is as follows: Year Ended December 31, 2016 2015 2014 U.S. federal tax at statutory rate 35.0 % 35.0 % 35.0 % State and local taxes - net of federal benefit 2.9 3.4 4.2 Credits and deductions related to research activities (1.3 ) (1.3 ) (1.7 ) Foreign rate differential benefit (2.3 ) (2.0 ) (0.6 ) Other, net (0.2 ) — — Provision for income taxes 34.1 % 35.1 % 36.9 %
Summary of Company's Net Deferred Tax Assets	The following is a summary of the Company’s net deferred tax assets: As of December 31, 2016 2015 (In thousands) Deferred tax assets U.S. net operating loss carryforwards $ 1,909 $ 2,580 Capital loss carryforwards 7,235 7,294 Stock compensation expense 11,307 9,115 Other 1,468 3,745 Total deferred tax assets 21,919 22,734 Valuation allowance (7,235 ) (7,294 ) Net deferred tax assets 14,684 15,440 Deferred tax liabilities Depreciation and amortization (1,456 ) (1,953 ) Capitalized software development costs (4,923 ) (4,344 ) Intangible assets (1,037 ) (1,310 ) Deferred tax assets, net $ 7,268 $ 7,833
Summary of Changes in Valuation Allowance	A summary of the changes in the valuation allowance is as follows: Year Ended December 31, 2016 2015 2014 (In thousands) Valuation allowance at beginning of year $ 7,294 $ 7,428 $ 7,743 (Decrease) to valuation allowance attributable to: Current year income — — (101 ) State net operating loss — — (155 ) Other changes (59 ) (134 ) (59 ) Valuation allowance at end of year $ 7,235 $ 7,294 $ 7,428
Reconciliation of the Unrecognized Tax Benefits	A reconciliation of the unrecognized tax benefits is as follows: Year Ended December 31, 2016 2015 2014 (In thousands) Balance at beginning of year $ 265 $ 265 $ 265 Reductions for tax positions of prior years (236 ) — — Balance at end of year $ 29 $ 265 $ 265

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Summary of the Change in the Company's Outstanding Shares of Common Stock	Year Ended December 31, 2016 2015 2014 (In thousands) Outstanding shares of voting common stock at the beginning of year 37,409 37,319 37,729 Exercise of stock options 181 183 120 Issuance of restricted stock, net of shares withheld for tax payments and cancellations 104 178 116 Repurchases (150 ) (271 ) (646 ) Outstanding shares of voting common stock at the end of year 37,544 37,409 37,319

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation Expense	Total stock-based compensation expense was as follows: Year Ended December 31, 2016 2015 2014 (In thousands) Employee: Restricted stock and performance shares $ 12,459 $ 10,792 $ 8,193 Stock options 1,143 826 676 13,602 11,618 8,869 Non-employee directors: Restricted stock 909 901 900 Total stock-based compensation $ 14,511 $ 12,519 $ 9,769
Assumptions Used for the Black-Scholes Option-Pricing Model to Determine the Per Share Weighted Average Fair Value for Options Granted	The following table represents the assumptions used for the Black-Scholes option-pricing model to determine the per share weighted-average fair value for options granted for the three years ended December 31, 2016: 2016 2015 2014 Expected life (years) 6.0 7.0 5.0 Risk-free interest rate 1.9 % 1.9 % 1.7 % Expected volatility 33.0 % 56.7 % 35.5 % Expected dividend yield 1.0 % 1.1 % 1.0 %
Stock Option Activity	The following table reports stock option activity during the three years ended December 31, 2016 and the intrinsic value as of December 31, 2016: Weighted- Remaining Number of Average Contractual Shares Exercise Price ($) Term Intrinsic Value ($) (In thousands) Outstanding at December 31, 2013 1,220,449 $ 15.01 Granted 382 63.07 Canceled (41,071 ) 41.47 Exercised (165,340 ) 15.85 Outstanding at December 31, 2014 1,014,420 13.81 Granted 120,650 88.15 Canceled — — Exercised (196,034 ) 11.60 Outstanding at December 31, 2015 939,036 23.83 Granted 112,988 102.40 Canceled (874 ) 101.77 Exercised (195,410 ) 12.35 $ 21,929 Outstanding at December 31, 2016 855,740 36.80 2.8 94,235 Exercisable at December 31, 2016 623,076 14.98 2.2 82,208
Summary of Performance of Share Activity for Annual Awards	The following table reports performance share activity for annual awards for the three years ended December 31, 2016: Performance year 2016 2015 2014 Share pay-out at plan 15,390 28,520 29,678 Actual share pay-out in following year 21,423 37,696 25,228 Weighted average fair value per share on grant date $ 101.77 $ 70.60 $ 63.07
Restricted Stock and Performance Share Activity	The following table reports restricted stock and performance share activity during the three years ended December 31, 2016: Weighted-Average Number of Grant Date Fair Restricted Shares Value Outstanding at December 31, 2013 569,734 $ 31.86 Granted 149,349 Performance share pay-out 46,340 Canceled (43,185 ) Vested (286,249 ) Outstanding at December 31, 2014 435,989 $ 41.83 Granted 117,668 Performance share pay-out 117,647 Canceled (3,845 ) Vested (235,321 ) Outstanding at December 31, 2015 432,138 $ 56.24 Granted 95,419 Performance share pay-out 61,936 Canceled (12,786 ) Vested (192,729 ) Outstanding at December 31, 2016 383,978 $ 71.50

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Common Share	The following table sets forth the computation of basic and diluted earnings per common share: Year Ended December 31, 2016 2015 2014 (In thousands, except per share amounts) Net income $ 126,172 $ 96,037 $ 74,806 Basic weighted average shares outstanding 36,844 36,690 36,930 Dilutive effect of stock options and restricted stock 894 947 959 Diluted weighted average shares outstanding 37,738 37,637 37,889 Basic earnings per share $ 3.42 $ 2.62 $ 2.03 Diluted earnings per share $ 3.34 $ 2.55 $ 1.97

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Summary of Minimum Rental Commitments under Operating Leases	Minimum rental commitments as of December 31, 2016 under such operating leases were as follows (in thousands): 2017 $ 4,438 2018 4,296 2019 9,205 2020 10,492 2021 10,079 2022 and thereafter 107,815 $ 146,325

Segment and Geographic Inform33

Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Summary of Revenue and Long-lived Assets	Information regarding revenue for the three years ended December 31, 2016, 2015 and 2014 and long-lived assets as of December 31, 2016 and 2015 follows: Year Ended December 31, 2016 2015 2014 (In thousands) Revenues United States $ 314,343 $ 262,558 $ 223,741 United Kingdom 54,015 39,338 38,189 Other 1,561 1,202 844 Total $ 369,919 $ 303,098 $ 262,774 As of December 31, 2016 2015 (In thousands) Long-lived assets, as defined United States $ 23,370 $ 21,968 United Kingdom 7,713 8,910 Other 21 19 Total $ 31,104 $ 30,897

Organization and Principal Bu34

Organization and Principal Business Activity - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016Institutional_Investor_and_Broker-dealer_Firm
Accounting Policies [Line Items]
Date of incorporation	Apr. 11, 2000
Minimum [Member]
Accounting Policies [Line Items]
Number of institutional investor and broker-dealer firms	1,200

Significant Accounting Polici35

Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Mar. 31, 2016
Significant Accounting Policies [Line Items]
Maximum maturity period for classification of investments as cash equivalents	3 months
Investments other-than-temporary losses	$ 0	$ 0	$ 0
Allowance for doubtful accounts	82,000	109,000	0
Provision for bad debts	200,000	200,000	100,000
Write-offs and other charges against the allowance for doubtful accounts	$ 100,000	100,000	$ 0
Term of agreement for revenue recognition	2 years
Deferred tax assets, net	$ 8,562,000	9,229,000
Other comprehensive income	(12,228,000)	(5,229,000)
Prepaid expenses and other assets	$ 11,618,000	$ 9,880,000
Restatement Adjustment [Member]
Significant Accounting Policies [Line Items]
Deferred tax assets, net				$ 3,100,000
Other comprehensive income				2,100,000
Prepaid expenses and other assets				$ 1,000,000
Maximum [Member]
Significant Accounting Policies [Line Items]
Contractual maturities accounts receivable	1 year
Estimated useful life of fixed assets	7 years
Maximum [Member] | Business Combinations [Member]
Significant Accounting Policies [Line Items]
Estimated life of intangible assets	15 years
Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of fixed assets	3 years
Minimum [Member] | Business Combinations [Member]
Significant Accounting Policies [Line Items]
Estimated life of intangible assets	3 years
Minimum [Member] | Internally Developed Software [Member]
Significant Accounting Policies [Line Items]
Estimated life of intangible assets	3 years

Net Capital Requirements - Addi

Net Capital Requirements - Additional Information (Detail) $ in Millions	Dec. 31, 2016USD ($)
Brokers And Dealers [Abstract]
Aggregate net capital and financial resources in excess of required level	$ 126
Aggregate net capital and financial resources, minimum capital requirement	$ 10.6

Fair Value Measurements - Valua

Fair Value Measurements - Valuation of Company's Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Money market funds	$ 58,573	$ 61,913
Securities available-for-sale		84,706
Trading securities	75,534
Assets Fair Value Total	252,711	146,973
Corporate Debt [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available-for-sale	118,870	82,671
Trading securities	74,207
Mutual Funds Held In Rabbi Trust [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Trading securities	1,327
Municipal Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available-for-sale		2,035
Foreign Currency Forward Position [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Foreign currency forward position	(266)	354
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Money market funds	58,573	61,913
Assets Fair Value Total	58,573	61,913
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets Fair Value Total	194,138	85,060
Level 2 [Member] | Corporate Debt [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available-for-sale	118,870	82,671
Trading securities	74,207
Level 2 [Member] | Mutual Funds Held In Rabbi Trust [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Trading securities	1,327
Level 2 [Member] | Municipal Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available-for-sale		2,035
Level 2 [Member] | Foreign Currency Forward Position [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Foreign currency forward position	$ (266)	$ 354

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Hedge derivative expiration period	1 month
Proceeds from the sales and maturities of securities available-for-sale	$ 69,500	$ 35,200	$ 17,600
Net realized gains on corporate debt trading securities	12
Net unrealized losses on corporate debt trading securities	$ (200)

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Foreign Currency Forward Contract (Detail) - Foreign Currency Forward Position [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Derivatives Fair Value [Line Items]
Notional value	$ 66,972	$ 45,716
Fair value of notional	67,238	45,362
Fair value of the (liability) asset	$ (266)	$ 354

Fair Value Measurements - Sum40

Fair Value Measurements - Summary of Company's Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule Of Available For Sale Securities [Line Items]
Securities available-for-sale, Amortized cost		$ 84,972
Securities available-for-sale, Gross unrealized gains		4
Securities available-for-sale, Gross unrealized losses		(270)
Securities available-for-sale, Estimated fair value		84,706
Trading securities, Amortized cost	$ 75,606
Trading securities, Gross unrealized gains	162
Trading securities, Gross unrealized losses	(234)
Trading securities, Estimated fair value	75,534
Investments, Amortized cost	194,679
Investments, Gross unrealized gains	175
Investments, Gross unrealized losses	(450)
Investments, Estimated fair value	194,404	84,706
Corporate Debt [Member]
Schedule Of Available For Sale Securities [Line Items]
Securities available-for-sale, Amortized cost	119,073	82,937
Securities available-for-sale, Gross unrealized gains	13	4
Securities available-for-sale, Gross unrealized losses	(216)	(270)
Securities available-for-sale, Estimated fair value	118,870	82,671
Trading securities, Amortized cost	74,394
Trading securities, Gross unrealized gains	47
Trading securities, Gross unrealized losses	(234)
Trading securities, Estimated fair value	74,207
Municipal Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Securities available-for-sale, Amortized cost		2,035
Securities available-for-sale, Estimated fair value		$ 2,035
Mutual Funds Held In Rabbi Trust [Member]
Schedule Of Available For Sale Securities [Line Items]
Trading securities, Amortized cost	1,212
Trading securities, Gross unrealized gains	115
Trading securities, Estimated fair value	$ 1,327

Fair Value Measurements - Sum41

Fair Value Measurements - Summary of Fair Value of Investments Based upon Contractual Maturities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Less than one year	$ 117,904	$ 37,694
Due in 1 - 5 years	76,500	47,012
Total	$ 194,404	$ 84,706

Fair Value Measurements - Fair

Fair Value Measurements - Fair Values and Unrealized Losses on Investments (Detail) - Corporate Debt [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule Of Available For Sale Securities [Line Items]
Less than Twelve Months, Estimated fair value	$ 136,667	$ 70,651
Less than Twelve Months, Gross unrealized losses	(449)	(270)
Twelve Months or More, Estimated fair value	2,000
Twelve Months or More, Gross unrealized losses	(1)
Estimated fair value, Total	138,667	70,651
Gross unrealized losses, Total	$ (450)	$ (270)

Goodwill and Intangible Asset43

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Line Items]
Goodwill and intangible assets with indefinite lives	$ 63,443	$ 64,142
Amortization expense associated with identifiable intangible assets	700	2,300	$ 2,300
Estimated total amortization expense 2017	400
Estimated total amortization expense 2018	400
Estimated total amortization expense 2019	400
Estimated total amortization expense 2020	400
Estimated total amortization expense 2021	400
Indefinite-lived Intangible Assets [Member]
Goodwill [Line Items]
Goodwill and intangible assets with indefinite lives	$ 59,700	$ 59,700

Goodwill and Intangible Asset44

Goodwill and Intangible Assets - Summary of Company's Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Finite Lived Intangible Assets [Line Items]
Cost	$ 12,148	$ 12,188
Accumulated Amortization	(8,417)	(7,757)
Net Carrying Amount	3,731	4,431
Technology [Member]
Finite Lived Intangible Assets [Line Items]
Cost	5,770	5,770
Accumulated Amortization	(5,770)	(5,492)
Net Carrying Amount		278
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Cost	5,628	5,668
Accumulated Amortization	(1,897)	(1,553)
Net Carrying Amount	3,731	4,115
Non-Competition Agreements [Member]
Finite Lived Intangible Assets [Line Items]
Cost	380	380
Accumulated Amortization	(380)	(359)
Net Carrying Amount		21
Tradenames - Finite Life [Member]
Finite Lived Intangible Assets [Line Items]
Cost	370	370
Accumulated Amortization	$ (370)	(353)
Net Carrying Amount		$ 17

Capitalized Software, Furnitu45

Capitalized Software, Furniture, Equipment and Leasehold Improvements - Capitalized Software Development Costs, Furniture, Equipment and Leasehold Improvements, Net of Accumulated Depreciation and Amortization (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	$ 106,283	$ 100,878
Accumulated depreciation and amortization	(75,179)	(69,981)
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	31,104	30,897
Software Development Costs [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	71,551	60,724
Computer Hardware and Related Software [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	20,152	26,328
Office Hardware [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	4,228	3,414
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	2,001	1,955
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	$ 8,351	$ 8,457

Capitalized Software, Furnitu46

Capitalized Software, Furniture, Equipment and Leasehold Improvements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Software development costs	$ 12.3	$ 10.6

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal	$ 45,455	$ 38,357	$ 31,700
State and local	7,087	7,180	6,505
Foreign	6,166	4,346	1,456
Total current provision	58,708	49,883	39,661
Deferred:
Federal	5,884	1,492	3,583
State and local	1,141	299	530
Foreign	(303)	189	(44)
Total deferred provision	6,722	1,980	4,069
Provision for income taxes	$ 65,430	$ 51,863	$ 43,730

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule Of Pre Tax Income [Line Items]
Pre-tax income from U.S. operations	$ 161.9	$ 126.4	$ 112.5
U.S. federal tax at statutory rate	35.00%	35.00%	35.00%
Additional annual limitations	50% or greater change
Percentage of change in ownership	50.00%
Additional annual limitations period	3 years
Capital loss on the sale	$ 20.6
Capital loss carried back	1.2
Undistributed earnings of foreign subsidiaries	36.9
Undistributed earnings of foreign subsidiaries, deferred tax liability	$ 1.2
New York State [Member] | Earliest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2,010
New York State [Member] | Latest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2,012
Foreign Country [Member]
Schedule Of Pre Tax Income [Line Items]
Pre-tax income from foreign operations	$ 29.7	$ 21.5	$ 6
US Country [Member]
Schedule Of Pre Tax Income [Line Items]
Net operating loss carryforwards	$ 5.4
Net operating loss carryforwards, expiration date	2,021

Income Taxes - Difference Betwe

Income Taxes - Difference Between the Company's Reported Provision for Income Taxes and the U.S. Federal Statutory Rate (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
U.S. federal tax at statutory rate	35.00%	35.00%	35.00%
State and local taxes - net of federal benefit	2.90%	3.40%	4.20%
Credits and deductions related to research activities	(1.30%)	(1.30%)	(1.70%)
Foreign rate differential benefit	(2.30%)	(2.00%)	(0.60%)
Other, net	(0.20%)
Provision for income taxes	34.10%	35.10%	36.90%

Income Taxes - Summary of Compa

Income Taxes - Summary of Company's Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred tax assets
Capital loss carryforwards	$ 7,235	$ 7,294
Stock compensation expense	11,307	9,115
Other	1,468	3,745
Total deferred tax assets	21,919	22,734
Valuation allowance	(7,235)	(7,294)	$ (7,428)	$ (7,743)
Net deferred tax assets	14,684	15,440
Deferred tax liabilities
Depreciation and amortization	(1,456)	(1,953)
Capitalized software development costs	(4,923)	(4,344)
Intangible assets	(1,037)	(1,310)
Deferred tax assets, net	7,268	7,833
US Country [Member]
Deferred tax assets
U.S. net operating loss carryforwards	$ 1,909	$ 2,580

Income Taxes - Summary of Chang

Income Taxes - Summary of Changes in Valuation Allowance (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Valuation allowance at beginning of year	$ 7,294	$ 7,428	$ 7,743
Current year income			(101)
State net operating loss			(155)
Other changes	(59)	(134)	(59)
Valuation allowance at end of year	$ 7,235	$ 7,294	$ 7,428

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 265	$ 265	$ 265
Reductions for tax positions of prior years	(236)	0	0
Balance at end of year	$ 29	$ 265	$ 265

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended												12 Months Ended
	Jan. 31, 2016	Jan. 31, 2014	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Oct. 31, 2016	Jul. 31, 2014
Class of Stock [Line Items]
Common stock, shares authorized			110,000,000				110,000,000								110,000,000	110,000,000
Common stock entitles															One
Shares repurchase program authorized	$ 25,000,000	$ 35,000,000																	$ 65,000,000
Amount available for repurchase			$ 51,100,000												$ 51,100,000
Cash dividends declared per common share			$ 0.26	$ 0.26	$ 0.26	$ 0.26	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.16	$ 0.16	$ 0.16	$ 0.16	$ 1.04	$ 0.80	$ 0.64
Share Repurchase Program [Member]
Class of Stock [Line Items]
Shares repurchase program period		2 years
Total shares repurchased		917,354
New Share Repurchase Program [Member]
Class of Stock [Line Items]
Shares repurchase program period	2 years
Total shares repurchased	155,868
Commencement date															Mar. 1, 2016
Shares repurchase program additional authorized amount																		$ 50,000,000
Common Stock Non-Voting [Member]
Class of Stock [Line Items]
Common stock, shares authorized			10,000,000				10,000,000								10,000,000	10,000,000
Common Stock Voting [Member]
Class of Stock [Line Items]
Common stock, shares authorized			110,000,000				110,000,000								110,000,000	110,000,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of the Companys Change in the Common Stock (Detail) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Outstanding shares of voting common stock at the beginning of year	37,409,274
Exercise of stock options	195,410	196,034	165,340
Outstanding shares of voting common stock at the end of year	37,543,775	37,409,274
Voting Common Stock [Member]
Class of Stock [Line Items]
Outstanding shares of voting common stock at the beginning of year	37,409,000	37,319,000	37,729,000
Exercise of stock options	181,000	183,000	120,000
Issuance of restricted stock, net of shares withheld for tax payments and cancellations	104,000	178,000	116,000
Repurchases	(150,000)	(271,000)	(646,000)
Outstanding shares of voting common stock at the end of year	37,544,000	37,409,000	37,319,000

Stock-Based Compensation Plan55

Stock-Based Compensation Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for grant under the stock incentive plans			360,035
Exercise price for the shares of the Company's common stock			$ 32.24	$ 36.46	$ 19.25
Grant date fair value			$ 21,929
Fair value assumptions, Dividend yield rate			1.00%	1.10%	1.00%
Closing price of common stock			$ 146.92
Unrecognized compensation costs related to non-vested			$ 4,100
Weighted-average period over which cost is expected to be recognized			3 years 2 months 12 days
Pay-out ranges, Minimum			0.00%
Pay-out ranges, Maximum			150.00%
Restricted Stock and Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs related to non-vested			$ 18,700
Weighted-average period over which cost is expected to be recognized			2 years
Employees Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period vested for option grants				1 year
Number of non-option equity instruments granted during the period			1,190	0
Percentage of shares grant to participants				20.00%
Chief Executive Officer [Member] | Incentive Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options Expiration Period		5 years 6 months
Exercise price for the shares of the Company's common stock		$ 88.25
Number of stock option equity instruments granted during the period		119,981
Grant date fair value		$ 2,000
Percentage of fair market value of the common stock on the grant date		125.00%
Fair value assumptions, Risk free interest rate		1.40%
Fair value assumptions, Volatility rate		27.30%
Fair value assumptions, Dividend yield rate		0.90%
Chief Executive Officer [Member] | Performance Based Share [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grant date fair value		$ 6,000
Fair value assumptions, Risk free interest rate		1.30%
Fair value assumptions, Volatility rate		27.30%
Fair value assumptions, Dividend yield rate		0.90%
Number of non-option equity instruments granted during the period		116,659
Share-based compensation arrangement by share-based payment award, equity instruments other than options, nonvested, number			24,240	92,419
Chief Executive Officer [Member] | Share-based Compensation Award, Tranche One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award award vesting date		Jan. 15, 2018
Chief Executive Officer [Member] | Share-based Compensation Award, Tranche One [Member] | Incentive Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting rights		33.33%
Chief Executive Officer [Member] | Share-based Compensation Award, Tranche One [Member] | Performance Based Share [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting rights		50.00%
Chief Executive Officer [Member] | Share-based Compensation Award, Tranche Two [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting rights		50.00%
Share-based compensation arrangement by share-based payment award award vesting date		Jan. 15, 2019
Chief Executive Officer [Member] | Share-based Compensation Award, Tranche Two [Member] | Incentive Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting rights		33.33%
Chief Executive Officer [Member] | Share-based Compensation Award, Tranche Three [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award award vesting date		Jan. 15, 2020
Chief Executive Officer [Member] | Share-based Compensation Award, Tranche Three [Member] | Incentive Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting rights		33.33%
Officers and Senior Managers [Member] | Performance Based Share [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options Expiration Period	3 years
Pay-out ranges, Minimum	0.00%
Pay-out ranges, Maximum	150.00%
Number of non-option equity instruments granted during the period	33,509
Fair value per share on the grant date	$ 103.30
Officers and Senior Managers [Member] | Share-based Compensation Award, Tranche One [Member] | Performance Based Share [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting rights	50.00%
Share-based compensation arrangement by share-based payment award award vesting date	Jan. 31, 2020
Officers and Senior Managers [Member] | Share-based Compensation Award, Tranche Two [Member] | Performance Based Share [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting rights	50.00%
Share-based compensation arrangement by share-based payment award award vesting date	Jan. 31, 2021
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period vested for option grants			3 years
Options Expiration Period			6 years
Minimum [Member] | Restricted Stock and Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period vested for option grants			3 years
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period vested for option grants			5 years
Options Expiration Period			10 years
Maximum [Member] | Restricted Stock and Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period vested for option grants			5 years

Stock-Based Compensation Plan56

Stock-Based Compensation Plans - Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employees [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 13,602	$ 11,618	$ 8,869
Employees [Member] | Restricted Stock and Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	12,459	10,792	8,193
Employees [Member] | Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	1,143	826	676
Non-Employee Directors [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	14,511	12,519	9,769
Non-Employee Directors [Member] | Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 909	$ 901	$ 900

Stock-Based Compensation Plan57

Stock-Based Compensation Plans - Assumptions Used for the Black-Scholes Option-Pricing Model to Determine the Per Share Weighted Average Fair Value for Options Granted (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected life (years)	6 years	7 years	5 years
Risk-free interest rate	1.90%	1.90%	1.70%
Expected volatility	33.00%	56.70%	35.50%
Expected dividend yield	1.00%	1.10%	1.00%

Stock-Based Compensation Plan58

Stock-Based Compensation Plans - Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Beginning balance	939,036	1,014,420	1,220,449
Number of Shares, Granted	112,988	120,650	382
Number of Shares, Canceled	(874)		(41,071)
Number of Shares, Exercised	(195,410)	(196,034)	(165,340)
Number of Shares, Ending Balance	855,740	939,036	1,014,420
Number of Shares, Exercisable	623,076
Weighted Average Exercise Price, Beginning Balance	$ 23.83	$ 13.81	$ 15.01
Weighted Average Exercise Price, Granted	102.40	88.15	63.07
Weighted Average Exercise Price, Canceled	101.77		41.47
Weighted Average Exercise Price, Exercised	12.35	11.60	15.85
Weighted Average Exercise Price, Ending Balance	36.80	$ 23.83	$ 13.81
Weighted Average Exercise Price, Exercisable	$ 14.98
Remaining Contractual Term, Outstanding at December 31, 2016	2 years 9 months 18 days
Remaining Contractual Term, Exercisable at December 31, 2016	2 years 2 months 12 days
Intrinsic Value, Exercised	$ 21,929
Intrinsic Value, Ending Balance	94,235
Intrinsic Value, Exercisable	$ 82,208

Stock-Based Compensation Plan59

Stock-Based Compensation Plans - Summary of Performance of Share Activity for Annual Awards (Detail) - Performance Shares [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share pay-out at plan	15,390	28,520	29,678
Actual share pay-out in following year	21,423	37,696	25,228
Weighted average fair value per share on grant date	$ 101.77	$ 70.60	$ 63.07

Stock-Based Compensation Plan60

Stock-Based Compensation Plans - Restricted Stock and Performance Share Activity (Detail) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Restricted Shares, Beginning balance	432,138	435,989	569,734
Number of Restricted Shares, Granted	95,419	117,668	149,349
Number of Restricted Shares, Performance share pay-out	61,936	117,647	46,340
Number of Restricted Shares, Canceled	(12,786)	(3,845)	(43,185)
Number of Restricted Shares, Vested	(192,729)	(235,321)	(286,249)
Number of Restricted Shares, Ending balance	383,978	432,138	435,989
Weighted Average Grant Date Fair Value, Beginning balance	$ 56.24	$ 41.83	$ 31.86
Weighted Average Grant Date Fair Value, Ending balance	$ 71.50	$ 56.24	$ 41.83

Earnings Per Share - Computatio

Earnings Per Share - Computation of Basic and Diluted Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share Basic And Diluted [Abstract]
Net income	$ 126,172	$ 96,037	$ 74,806
Basic weighted average shares outstanding	36,844	36,690	36,930
Dilutive effect of stock options and restricted stock	894	947	959
Diluted weighted average shares outstanding	37,738	37,637	37,889
Basic earnings per share	$ 3.42	$ 2.62	$ 2.03
Diluted earnings per share	$ 3.34	$ 2.55	$ 1.97

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock Options and Restricted Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options and restricted stock excluded from the computation of diluted earnings per share	84,052	128,383	66,637

Credit Agreement - Additional I

Credit Agreement - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Jan. 31, 2013	Dec. 31, 2016	Oct. 31, 2015
Line Of Credit Facility [Line Items]
Revolving loans and letters of credit	$ 50,000,000		$ 100,000,000
Letter of credit outstanding		$ 900,000
Additional Credit Agreement	$ 50,000,000
Amount available under credit agreement		$ 99,100,000
Period of credit agreement	3 years
LIBOR rate description		(A) the sum of (i) the greatest of (a) the prime rate, as defined, (b) the federal funds effective rate plus 0.50% and (c) one month adjusted LIBOR plus 1.00% plus (ii) 0.50% or (B) the sum of (i) adjusted LIBOR plus (ii) 1.50%
Federal funds effective rate		0.50%
One month adjusted LIBOR		1.00%
LIBOR Rate		0.50%
Adjusted LIBOR rate		1.50%
Interest per annum		2.00%
Revolving loan commitment rate		0.40%
Equity interest		65.00%
Maximum [Member]
Line Of Credit Facility [Line Items]
Total leverage ratio		250.00%
Minimum [Member]
Line Of Credit Facility [Line Items]
Interest coverage ratio		350.00%
Adjusted EBITDA		$ 80,000,000
Excess judgments against the company		$ 10,000,000
Standby Letters of Credit [Member]
Line Of Credit Facility [Line Items]
Revolving loans and letters of credit			$ 5,000,000
Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Expiration period of credit agreement		Oct. 31, 2017

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)ft²AgreementSubsidiary	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Loss Contingencies [Line Items]
Non-cancelable leases expiration date	Dec. 31, 2033
Rental expense	$ 4,000	$ 4,100	$ 3,800
Aggregate minimum rental commitment under non-cancelable leases	$ 146,325
Number of lease agreements assigned to third parties | Agreement	1
Lease termination dates	2020-11
Future lease obligation under sublease arrangements	$ 1,000
Number of subsidiaries | Subsidiary	2
Settlement days of bond transaction	Within one to three trading days
Revenues from riskless principal transactions	$ 37,700	16,900	7,400
Collateral deposits	1,100
General and Administrative Expense [Member]
Loss Contingencies [Line Items]
Clearing expenses	6,100	$ 3,300	$ 1,300
Standby Letters of Credit [Member]
Loss Contingencies [Line Items]
Contingent obligation for standby letter of credit issued to Landlord	$ 900
Non-Cancelable Leases Commence on or after December 1, 2016 [Member]
Loss Contingencies [Line Items]
Non-cancelable leases expiration date	Dec. 31, 2033
Area of office space under non-cancelable leases | ft²	108,000
Non-cancelable leases commencement date	Dec. 1, 2016
Aggregate minimum rental commitment under non-cancelable leases	$ 127,400

Commitments and Contingencies65

Commitments and Contingencies - Summary of Minimum Rental Commitments under Operating Leases (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Operating Leases Future Minimum Payments Due [Abstract]
2,017	$ 4,438
2,018	4,296
2,019	9,205
2,020	10,492
2,021	10,079
2022 and thereafter	107,815
Operating Leases	$ 146,325

Segment and Geographic Inform66

Segment and Geographic Information - Additional Information (Detail) - Segment	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues From External Customers And Long Lived Assets [Line Items]
Number of operating segment	1
Geographic Concentration Risk [Member] | Total Revenue and Long-lived Assets [Member] | United Kingdom [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Concentration Risk, Percentage	10.00%	10.00%	10.00%

Segment and Geographic Inform67

Segment and Geographic Information - Summary of Revenue and Long-lived Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenues	$ 369,919	$ 303,098	$ 262,774
Long-lived assets	31,104	30,897
United States [Member]
Segment Reporting Information [Line Items]
Revenues	314,343	262,558	223,741
Long-lived assets	23,370	21,968
United Kingdom [Member]
Segment Reporting Information [Line Items]
Revenues	54,015	39,338	38,189
Long-lived assets	7,713	8,910
Other [Member]
Segment Reporting Information [Line Items]
Revenues	1,561	1,202	$ 844
Long-lived assets	$ 21	$ 19

Retirement and Deferred Compe68

Retirement and Deferred Compensation Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Compensation And Retirement Disclosure [Abstract]
Contribution to defined plans	$ 1.9	$ 1.9	$ 1.8
Non-qualified deferred cash incentive plan maximum eligibility percentage of employees		100.00%
Mutual fund investments and deferred compensation obligation, at fair value	1.3
Trading gain and compensation expense	$ 0.2

Customer Concentration - Additi

Customer Concentration - Additional Information (Detail) - Customer	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Concentration Risk [Line Items]
Number of client accounted for more than 10% of total revenue	0	0	0
Percentage of outstanding shares owned by single client	7.60%
Customer Concentration Risk [Member] | Trading Volume [Member]
Concentration Risk [Line Items]
Percentage of trading volumes by single client	14.20%	15.30%	14.00%