MarketAxess (MKTX) 10-K 18 Feb 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 12, 2020	Jun. 30, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Trading Symbol	MKTX
Entity Registrant Name	MARKETAXESS HOLDINGS INC
Entity Central Index Key	0001278021
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		37,921,561
Entity Public Float			$ 10.5
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, $0.003 par value
Security Exchange Name	NASDAQ
Entity File Number	001-34091
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	52-2230784
Entity Address, Address Line One	55 Hudson Yards
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10001
Document Annual Report	true
Document Transition Report	false
City Area Code	212
Local Phone Number	813-6000
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement for the 2020 Annual Meeting of Stockholders are incorporated by reference into Items 10, 11, 12, 13 and 14 of Part III of this Form 10-K.

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
ASSETS
Cash and cash equivalents	$ 270,124	$ 246,322
Investments, at fair value	230,477	240,105
Accounts receivable, net of allowance of $57 and $80 as of December 31, 2019 and 2018, respectively	62,017	57,535
Goodwill	146,861	59,713
Intangible assets, net of accumulated amortization	60,986	2,962
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	71,795	63,010
Operating lease right-of-use assets	81,399
Prepaid expenses and other assets	30,770	22,468
Deferred tax assets, net	501	3,424
Total assets	954,930	695,539
Liabilities
Accrued employee compensation	47,365	39,053
Income and other tax liabilities	16,690	16,432
Deferred revenue	3,499	2,810
Accounts payable, accrued expenses and other liabilities	19,294	29,366
Operating lease liabilities	97,991
Total liabilities	184,839	87,661
Commitments and Contingencies (Note 14)
Stockholders' equity
Preferred stock
Common stock	122	122
Additional paid-in capital	342,541	341,860
Treasury stock - Common stock voting, at cost, 2,810,609 and 2,900,432 shares as of December 31, 2019 and 2018, respectively	(153,388)	(184,962)
Retained earnings	591,086	463,252
Accumulated other comprehensive loss	(10,270)	(12,394)
Total stockholders' equity	770,091	607,878
Total liabilities and stockholders' equity	954,930	695,539
Series A Preferred Stock [Member]
Stockholders' equity
Preferred stock

Consolidated Statements of Fi_2

Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Allowance for accounts receivable	$ 57	$ 80
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	40,746,593	40,540,349
Common stock, shares outstanding	37,935,984	37,639,917
Treasury stock, shares	2,810,609	2,900,432
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, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues
Revenues	$ 511,352	$ 435,565	$ 393,422
Expenses
Employee compensation and benefits	131,079	109,117	102,313
Depreciation and amortization	26,857	23,080	19,274
Technology and communications	26,792	23,866	20,048
Professional and consulting fees	25,534	21,521	19,367
Occupancy	11,639	14,176	6,125
Marketing and advertising	11,559	12,114	9,762
Clearing costs	11,314	7,754	5,797
General and administrative	15,696	11,353	11,121
Total expenses	260,470	222,981	193,807
Operating income	250,882	212,584	199,615
Other income (expense)
Investment income	8,063	6,112	3,619
Other, net	(1,521)	(610)	(1,466)
Total other income	6,542	5,502	2,153
Income before income taxes	257,424	218,086	201,768
Provision for income taxes	52,522	45,234	53,679
Net income	$ 204,902	$ 172,852	$ 148,089
Net income per common share
Basic	$ 5.53	$ 4.68	$ 4.02
Diluted	5.40	4.57	3.89
Cash dividends declared per common share	$ 2.04	$ 1.68	$ 1.32
Weighted average shares outstanding
Basic	37,083	36,958	36,864
Diluted	37,956	37,855	38,038
Commissions [Member]
Revenues
Revenues	$ 463,856	$ 390,834	$ 355,282
Information Services [Member]
Revenues
Revenues	30,730	28,227	25,806
Post-trade Services [Member]
Revenues
Revenues	15,763	15,346	11,090
Other [Member]
Revenues
Revenues	$ 1,003	$ 1,158	$ 1,244

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 204,902	$ 172,852	$ 148,089
Net cumulative translation adjustment and foreign currency exchange hedge, net of tax of $(1,218), $1,290 and $(2,807), respectively	1,128	(2,078)	2,236
Net unrealized gain (loss) on securities available-for-sale, net of tax of $312, $(23), and $(39), respectively	996	(90)	(234)
Comprehensive income	$ 207,026	$ 170,684	$ 150,091

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Foreign currency exchange hedge, tax expense (benefit)	$ (1,218)	$ 1,290	$ (2,807)
Securities available-for-sale, tax expense (benefit)	$ 312	$ (23)	$ (39)

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 [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Dec. 31, 2016	$ 468,013	$ 120	$ 342,311	$ (117,330)	$ 255,140	$ (12,228)
Net income	148,089				148,089
Cumulative translation adjustment and foreign currency exchange hedge, net of tax	2,236					2,236
Unrealized net gain (loss) on securities available-for-sale, net of tax	(234)					(234)
Stock-based compensation	14,421		14,421
Exercise of stock options	1,972	1	1,971
Withholding tax payments on restricted stock vesting and stock option exercises	(27,691)		(27,691)
Repurchases of common stock	(42,461)			(42,461)
Cumulative effect of change in accounting for employee share-based payments	17		69		(52)
Cash dividend on common stock	(49,594)				(49,594)
Ending Balance at Dec. 31, 2017	514,768	121	331,081	(159,791)	353,583	(10,226)
Net income	172,852				172,852
Cumulative translation adjustment and foreign currency exchange hedge, net of tax	(2,078)					(2,078)
Unrealized net gain (loss) on securities available-for-sale, net of tax	(90)					(90)
Stock-based compensation	15,850		15,850
Exercise of stock options	2,973	1	2,972
Withholding tax payments on restricted stock vesting and stock option exercises	(8,043)		(8,043)
Repurchases of common stock	(25,171)			(25,171)
Cash dividend on common stock	(63,183)				(63,183)
Ending Balance at Dec. 31, 2018	607,878	122	341,860	(184,962)	463,252	(12,394)
Net income	204,902				204,902
Cumulative translation adjustment and foreign currency exchange hedge, net of tax	1,128					1,128
Unrealized net gain (loss) on securities available-for-sale, net of tax	996					996
Stock-based compensation	25,294		25,294
Exercise of stock options	1,207		1,207
Withholding tax payments on restricted stock vesting and stock option exercises	(25,820)		(25,820)
Treasury shares used for acquisition	48,830			48,830
Repurchases of common stock	(17,256)			(17,256)
Cash dividend on common stock	(77,068)				(77,068)
Ending Balance at Dec. 31, 2019	$ 770,091	$ 122	$ 342,541	$ (153,388)	$ 591,086	$ (10,270)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities
Net income	$ 204,902	$ 172,852	$ 148,089
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	26,857	23,080	19,274
Amortization of operating lease right-of-use assets	5,795
Stock-based compensation expense	25,294	15,850	14,421
Deferred taxes	2,682	(1,258)	6,590
Other	(786)	2,338	1,953
Changes in operating assets and liabilities:
(Increase) in accounts receivable	(2,962)	(5,117)	(2,353)
(Increase) in prepaid expenses and other assets	(4,624)	(3,791)	(7,039)
Decrease (Increase) in trading securities	4,045	856	(17,081)
Increase in accrued employee compensation	8,312	2,551	1,719
Increase in income and other tax liabilities	187	2,965	5,770
Increase in deferred revenue	689	150	145
(Decrease) increase in accounts payable, accrued expenses and other liabilities	(1,509)	14,374	(1,614)
(Decrease) in operating lease liabilities	(829)
Net cash provided by operating activities	265,935	223,917	168,035
Cash flows from investing activities
Acquisition of business, net of cash and cash equivalents acquired	(97,430)
Proceeds from maturities and sales, available-for-sale investments	170,936	333,791	187,794
Purchases, available-for-sale investments	(160,827)	(336,533)	(215,831)
Purchases of furniture, equipment and leasehold improvements	(12,292)	(35,888)	(12,086)
Capitalization of software development costs	(22,408)	(11,705)	(13,471)
Other	(30)	39	(59)
Net cash (used in) investing activities	(122,051)	(50,296)	(53,653)
Cash flows from financing activities
Cash dividend on common stock	(76,231)	(62,432)	(48,888)
Exercise of stock options	1,207	2,973	1,972
Withholding tax payments on restricted stock vesting and stock option exercises	(25,820)	(8,043)	(27,691)
Repurchases of common stock	(17,256)	(25,171)	(42,461)
Net cash (used in) financing activities	(118,100)	(92,673)	(117,068)
Effect of exchange rate changes on cash and cash equivalents	1,011	(1,640)	1,457
Cash and cash equivalents including restricted cash
Net increase (decrease) for the period	26,795	79,308	(1,229)
Beginning of period	247,458	168,150	169,379
End of period	274,253	247,458	168,150
Supplemental cash flow information:
Cash paid during the year for income taxes	51,766	47,208	43,997
Right-of-use assets obtained in exchange for operating lease liabilities	7,464
Non-cash investing and financing activity:
Fair value of assets acquired	148,425
Acquisition of business, net of cash and cash equivalents acquired	(97,430)
Treasury stock used for acquisition of business	(48,830)
Liabilities assumed	2,165
Mutual Funds Held In Rabbi Trust [Member]
Changes in operating assets and liabilities:
Decrease (Increase) in trading securities	$ (2,118)	$ (933)	$ (1,839)

Organization and Principal Busi

Organization and Principal Business Activity	12 Months Ended
	Dec. 31, 2019
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 leading electronic trading platforms delivering expanded liquidity opportunities, improved execution quality and significant cost savings across global fixed-income markets. Over 1,700 institutional investor and broker-dealer firms are active users of MarketAxess’ patented trading technology, accessing global liquidity on our platforms in U.S. investment-grade bonds, U.S. high-yield bonds, U.S. Treasuries, emerging market debt, Eurobonds and other fixed income securities. Through its Open Trading TM TM

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
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. Accounting Pronouncements, Recently Adopted In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-15, “Intangibles—Goodwill and Other—Internal-Use Software: Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract” (“ASU 2018-15”). The standard requires the capitalization of implementation costs incurred in a cloud computing arrangement to be aligned with the requirements for capitalizing costs incurred to develop or obtain internal use software. The updated guidance is effective for annual and interim reporting periods beginning after December 15, 2019, with early adoption permitted. The Company adopted ASU 2018-15 effective July 1, 2019 on a prospective basis. The Company completed its analysis and the adoption of this guidance did not have a material impact 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 with lease terms greater than 12 months. The Company adopted ASU 2016-02 effective January 1, 2019 using a modified retrospective transition approach and will not restate comparative periods. In addition, the Company elected the package of practical expedients permitted under the transition guidance within the new standard which allowed it to carry forward the historical lease classification. In May 2014, the FASB issued 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 also requires new disclosure concerning contracts with customers, including the significant judgments made when applying the guidance. The Company adopted ASU 2014-09 effective January 1, 2018 using the modified retrospective transition approach. The adoption of this guidance did not have a material impact on the Company’s Consolidated Financial Statements. Accounting Pronouncements, Not Yet Adopted as of December 31, 2019 In January 2017, the FASB issued ASU 2017-04, “Intangibles-Goodwill and Other” (“ASU 2017-04”). ASU 2017-04 simplifies the testing for goodwill impairment. The guidance will be effective for the Company beginning January 1, 2020 and early adoption is permitted and should be applied prospectively. The adoption of this guidance is not expected to have a material effect on the Company’s Consolidated Financial Statements. 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 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 include investment grade corporate debt securities and U.S. Treasuries and are carried at fair value, with realized and unrealized gains or losses included in other, net 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, 2019, 2018 and 2017. 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 $0.2 million as of December 31, 2019, 2018 and 2017, respectively. The provision for bad debts was $0.3 million, $0.2 million and $0.4 million for the years ended December 31, 2019, 2018 and 2017, respectively. Write-offs and other charges against the allowance for doubtful accounts were $0.1 million, $0.2 million and $0.1 million for the years ended December 31, 2019, 2018 and 2017, 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. Cloud Computing Costs The Company capitalizes certain costs associated with cloud computing arrangements, including, among other items, employee compensation and related benefits and third-party consulting costs that are part of the application development stage. These costs are setup as a prepaid asset on the balance sheet and are amortized over the period of the hosting service contract. 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 other, net 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 Company’s classification of revenues in the Consolidated Statements of Operations represents revenues from contracts with customers disaggregated by type of revenue. The Company has four revenue streams as described below. Commission Revenue. The Company charges its broker-dealer clients variable transaction fees for trades executed on its platform and, under certain plans, distribution fees or monthly minimum fees to use the platform for a particular product area. Variable transaction fees 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 disclosed trading transaction fee plans, bonds that are more actively traded or that have shorter maturities generally generate lower commissions, while bonds that are less actively traded or that have longer maturities generally command higher commissions. Variable transaction fees, distribution fees and unused monthly fee commitments are invoiced and recorded on a monthly basis. For Open Trading 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 its commission through the difference in price between the two trades. The commission is collected upon settlement of the trade, which typically occurs within one to two trading days after the trade date. For U.S. Treasury matched principal trades, commissions are invoiced and recorded on a monthly basis. The following table presents commission revenue by fee type: Year Ended December 31, 2019 2018 2017 (In thousands) Commission revenue by fee type Variable transaction fees Disclosed trading $ 266,916 $ 228,004 $ 234,143 Open Trading - matched principal trading 98,080 65,932 45,660 U.S. Treasuries - matched principal trading 2,184 — — Total variable transaction fees 367,180 293,936 279,803 Distribution fees and unused minimum fees 96,676 96,898 75,479 Total commissions $ 463,856 $ 390,834 $ 355,282 Information services – Information services includes data licensed to the Company’s broker-dealer clients, institutional investor clients and data-only subscribers; professional and consulting services; technology software licenses; and maintenance and support services. The nature and timing of each performance obligation may vary as these contracts are either subscription - based services transferred over time , and may be net of volume -based discounts , or one-time services that are transferred at a point in time. Revenues for services transferred over time are recognized ratably over the contract period as the Company’s performance obligation is met whereas revenues for services transferred at a point in time are recognized in the period the services are provided. Customers are generally billed monthly, quarterly, or annually; revenues billed in advance are deferred and recognized ratably over the contract period. The following table presents information services revenue by timing of recognition: Year Ended December 31, 2019 2018 2017 (In thousands) Information services revenue by timing of recognition Services transferred over time $ 29,619 $ 27,475 $ 25,242 Services transferred at a point in time 1,111 752 564 Total information services revenues $ 30,730 $ 28,227 $ 25,806 Post-trade services – Post-trade services revenue is generated from regulatory transaction reporting, trade publication and trade matching services. Customers are generally billed monthly in arrears and revenue is recognized in the period transactions are processed. Revenues billed in advance are deferred and recognized ratably over the contract period. The Company also generates one-time implementation fees for onboarding clients which are invoiced and recognized in the period the implementation is completed. The following table presents post-trade services revenue by timing of recognition: Year Ended December 31, 2019 2018 2017 (In thousands) Post-trade services revenue by timing of recognition Services transferred over time $ 15,669 $ 15,013 $ 9,657 Services transferred at a point in time 94 333 1,433 Total post-trade services revenues $ 15,763 $ 15,346 $ 11,090 Other revenues – Other revenues primarily includes revenue from telecommunications line charges to broker-dealer clients. Contract liabilities consist of deferred revenues that the Company records when cash payments are received or due in advance of services to be performed. The revenue recognized from contract liabilities and the remaining balance is shown below: December 31, 2018 Payments received in advance of services to be performed Revenue recognized for services performed during the period Foreign Currency Translation December 31, 2019 (In thousands) Information services $ 1,959 $ 7,439 $ (7,260 ) $ — $ 2,138 Post-trade services 851 13,617 (13,136 ) 29 1,361 Total deferred revenue $ 2,810 $ 21,056 $ (20,396 ) $ 29 $ 3,499 The majority of the Company’s contracts are short-term in nature with durations of less than one-year. For contracts extending beyond one year, the aggregate amount of the transaction price allocated to remaining performance obligations was $41.7 million as of December 31, 2019. The Company expects to recognize revenue associated with the remaining performance obligations over the next 31 months. 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. Forfeitures are recognized as they occur. 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 other, net in the Consolidated Statements of Operations. All tax effects related to share-based payments are recorded through tax expense in the periods during which the awards are exercised or vest. 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, customer attrition 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 over their estimated useful lives which range from one to 15 years using either a straight-line or accelerated amortization method based on the pattern of economic benefit the Company expects to realize from such assets. 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 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.

Net Capital Requirements

Net Capital Requirements	12 Months Ended
	Dec. 31, 2019
Brokers And Dealers [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 (“SEC”) 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 other foreign regulators and must maintain financial resources, as defined in the applicable regulations, in excess of the applicable financial resources requirement. As of December 31, 2019, 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, 2019, the Company’s subsidiaries maintained aggregate net capital and financial resources that were $219.7 million in excess of the required levels of $15.8 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, 2019
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 (In thousands) As of December 31, 2019 Money market funds $ 99,755 $ — $ — $ 99,755 Securities available-for-sale Corporate debt — 137,835 — 137,835 Trading securities Corporate debt — 31,120 — 31,120 U.S. Treasuries — 55,305 — 55,305 Mutual funds held in rabbi trust — 6,217 — 6,217 Foreign currency forward position — (2,772 ) — (2,772 ) Total $ 99,755 $ 227,705 $ — $ 327,460 As of December 31, 2018 Money market funds $ 112,529 $ — $ — $ 112,529 Securities available-for-sale Corporate debt — 146,966 — 146,966 Trading securities Corporate debt — 71,861 — 71,861 U.S. Treasuries — 17,178 — 17,178 Mutual funds held in rabbi trust — 4,100 — 4,100 Foreign currency forward position — (1,021 ) — (1,021 ) Total $ 112,529 $ 239,084 $ — $ 351,613 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 Company’s deferred cash incentive plan. There were no financial assets classified within Level 3 during the years ended December 31, 201 9 and 201 8 . 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 As of December 31, 2019 2018 (In thousands) Notional value $ 155,885 $ 106,306 Fair value of notional 158,657 107,327 Fair value of the (liability) $ (2,772 ) $ (1,021 ) The following is a summary of the Company’s investments: Amortized cost Gross unrealized gains Gross unrealized losses Estimated fair value (In thousands) As of December 31, 2019 Securities available-for-sale Corporate debt $ 137,119 $ 721 $ (5 ) $ 137,835 Trading securities Corporate debt 31,120 14 (14 ) 31,120 U.S. Treasuries 54,738 567 — 55,305 Mutual funds held in rabbi trust 5,173 1,044 — 6,217 Total trading securities 91,031 1,625 (14 ) 92,642 Total investments $ 228,150 $ 2,346 $ (19 ) $ 230,477 As of December 31, 2018 Securities available-for-sale Corporate debt $ 147,556 $ 27 $ (617 ) $ 146,966 Trading securities Corporate debt 72,274 8 (421 ) 71,861 U.S. Treasuries 16,953 225 — 17,178 Mutual funds held in rabbi trust 4,347 — (247 ) 4,100 Total trading securities 93,574 233 (668 ) 93,139 Total investments $ 241,130 $ 260 $ (1,285 ) $ 240,105 The following table summarizes the fair value of the investments based upon the contractual maturities: As of December 31, 2019 2018 (In thousands) Less than one year $ 120,850 $ 134,255 Due in 1 - 5 years 109,627 105,850 Total $ 230,477 $ 240,105 Proceeds from the sales and maturities of investments during the years ended December 31, 2019, 2018 and 2017 were $262.1 million, $409.3 million and $219.2 million, respectively. Net unrealized gains on trading securities were $0.8 million for the year ended December 31, 2019 and were immaterial for the years ended December 31, 2018 and 2017. Net realized gains and losses were immaterial for the three years ended December 31, 2019. The following table provides fair values and unrealized losses on corporate debt investments and by the aging of the securities' continuous unrealized loss position as of December 31, 2019 and 2018 respectively: Less than Twelve Months Twelve Months or More Total Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses (In thousands) As of December 31, 2019 Corporate debt $ 27,999 $ (18 ) $ 4,406 $ (1 ) $ 32,405 $ (19 ) As of December 31, 2018 Corporate debt $ 80,282 $ (256 ) $ 87,028 $ (782 ) $ 167,310 $ (1,038 )

Acquisition

Acquisition	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Acquisition	5. Acquisition On November 1, 2019, the Company and one of its subsidiaries completed their acquisition (the “Acquisition”) of all of the outstanding equity interests of LiquidityEdge LLC (“LiquidityEdge”) pursuant to the terms and conditions of a Unit Purchase Agreement entered into among the Company, LiquidityEdge, the holders of all the outstanding equity interests in LiquidityEdge and certain other persons named therein on August 12, 2019 (as amended, the “Agreement”). The aggregate consideration for the Acquisition was $152.7 million, comprised of approximately $103.9 million in cash and 146,450 shares of common stock of the Company (valued at approximately $48.8 million as of the closing date of the Acquisition, as described below). The aggregate consideration is subject to customary adjustments for cash on hand, outstanding debt, transaction expenses and working capital as set forth in the Agreement. A portion of the stock consideration, amounting to 43,937 shares of common stock, was placed in escrow for up to 18 months to secure the sellers’ indemnification obligations under the Agreement. In addition, under the Agreement, the sellers are generally prohibited from transferring any of the Company common stock received in the Acquisition for a period of six months following the November 1, 2019 closing date. The value ascribed to the shares by the Company was discounted from the market value on the date of closing to reflect the non-marketability of such shares during the restriction period. LiquidityEdge is a limited liability company organized in the state of Delaware and is a broker-dealer registered with the SEC and the Financial Industry Regulatory Authority. LiquidityEdge offers an electronic trading platform for U.S. Treasuries. The Company has completed a preliminary allocation of the purchase price to the fair value of assets acquired and liabilities assumed at the date of acquisition. The Company utilized an independent third-party to determine the fair value of the acquired intangible assets. It is possible that the purchase price allocation will be adjusted upon finalization of the accounting for the acquired assets. The preliminary purchase price allocation is as follows (in thousands): Purchase price $ 152,677 Less: acquired cash (2,935 ) Purchase price, net of acquired cash 149,742 Accounts receivable (1,811 ) Intangible assets (58,780 ) Prepaid expenses and other assets (4,168 ) Accounts payable, accrued expenses and other liabilities 2,165 Goodwill $ 87,148 The acquired intangible assets are as follows (in thousands, except for useful lives): Costs Useful Lives Customer relationships $ 58,690 15 years Tradename - finite life 90 1 year Total $ 58,780

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	6. Goodwill and Intangible Assets The following is a summary of changes in goodwill and intangible assets with indefinite lives for the year ended December 31, 2019 (in thousands): Balance at beginning of period $ 59,713 Goodwill from LiquidityEdge acquisition 87,148 Balance at end of period $ 146,861 Intangible assets that are subject to amortization, including the related accumulated amortization, are comprised of the following: December 31, 2019 December 31, 2018 Cost Accumulated amortization Net carrying amount Cost Accumulated amortization Net carrying amount (In thousands) Technology $ 5,770 $ (5,770 ) $ — $ 5,770 $ (5,770 ) $ — Customer relationships 64,332 (3,451 ) 60,881 5,634 (2,672 ) 2,962 Non-competition agreements 380 (380 ) — 380 (380 ) — Tradenames and patents 490 (385 ) 105 370 (370 ) — Total $ 70,972 $ (9,986 ) $ 60,986 $ 12,154 $ (9,192 ) $ 2,962 Amortization expense associated with identifiable intangible assets was $0.8 million, $0.4 million and $ 0.4 million for the years ended December 31, 2019, 2018 and 2017, respectively. Annual estimated total amortization expense is $3.3 million, $5.7 million, $6.9 million, $7.9 million and $6.7 million for 2020 through 2024.

Capitalized Software, Furniture

Capitalized Software, Furniture, Equipment and Leasehold Improvements	12 Months Ended
	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Capitalized Software, Furniture, Equipment and Leasehold Improvements	7. 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, 2019 2018 (In thousands) Software development costs $ 119,911 $ 97,113 Computer hardware and related software 48,379 42,705 Office hardware 5,725 5,909 Furniture and fixtures 5,000 5,385 Leasehold improvements 27,966 32,527 206,981 183,639 Accumulated depreciation and amortization (135,186 ) (120,629 ) Total $ 71,795 $ 63,010 During the years ended December 31, 2019 and 2018, software development costs totaling $22.4 million and $11.7 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, 2019
Income Tax Disclosure [Abstract]
Income Taxes	8. Income Taxes The provision for income taxes consists of the following: Year Ended December 31, 2019 2018 2017 (In thousands) Current: Federal $ 28,928 $ 31,617 $ 36,045 State and local 7,686 5,928 3,848 Foreign 13,234 8,862 7,234 Total current provision 49,848 46,407 47,127 Deferred: Federal 2,579 (1,416 ) 6,171 State and local 403 (272 ) 661 Foreign (308 ) 515 (280 ) Total deferred provision 2,674 (1,173 ) 6,552 Provision for income taxes $ 52,522 $ 45,234 $ 53,679 Pre-tax income from U.S. operations was $190.4 million, $168.5 million and $165.2 million for the years ended December 31, 2019, 2018 and 2017, respectively. Pre-tax income from foreign operations was $67.0 million, $49.6 million and $36.6 million for the years ended December 31, 2019, 2018 and 2017, respectively. On December 22, 2017, the Tax Cut and Jobs Act (“Tax Act”) was enacted into law. The Tax Act significantly revised the U.S. corporate income tax regime by, among other things, lowering the U.S. federal corporate income tax rate from 35% to 21%, implementing a territorial tax system and imposing a repatriation tax on deemed earnings of foreign subsidiaries. The Company recorded a provisional tax charge in 2017 of $11.7 million, composed of $6.7 million to re-measure U.S. deferred tax assets and $5.0 million for the repatriation tax on accumulated undistributed foreign earnings. In 2018, the Company reduced the provisional tax charge by $0.4 million as a result of new regulatory guidance and changes in interpretations and assumptions made by the Company. The difference between the Company’s reported provision for income taxes and the U.S. federal statutory rate of 21% is as follows: Year Ended December 31, 2019 2018 2017 U.S. federal tax at statutory rate 21.0 % 21.0 % 35.0 % State and local taxes - net of federal benefit 2.5 2.0 1.5 Credits and deductions related to research activities (0.3 ) (0.3 ) (1.2 ) Foreign rate differential benefit (0.5 ) (0.5 ) (2.9 ) Excess tax benefit from stock-based compensation (3.5 ) (2.1 ) (11.6 ) Tax Cuts and Jobs Act provisional tax charge — (0.2 ) 5.8 Other, net 1.2 0.8 — Provision for income taxes 20.4 % 20.7 % 26.6 % The following is a summary of the Company’s net deferred tax assets: As of December 31, 2019 2018 (In thousands) Deferred tax assets: Stock compensation expense $ 4,926 $ 4,967 Operating lease liabilities 20,227 — Other 892 3,569 Total deferred tax assets 26,045 8,536 Valuation allowance — — Net deferred tax assets 26,045 8,536 Deferred tax liabilities: Depreciation and amortization (4,085 ) (1,847 ) Capitalized software development costs (5,306 ) (3,776 ) Goodwill and intangible assets (1,120 ) (898 ) Operating lease right-of-use assets (16,515 ) — Deferred tax (liability) asset, net $ (981 ) $ 2,015 A summary of the changes in the valuation allowance is as follows: Year Ended December 31, 2019 2018 2017 (In thousands) Valuation allowance at beginning of year $ — $ 4,648 $ 7,235 (Decrease) to valuation allowance attributable to: Expiration of capital loss carryforwards — (4,648 ) — Federal and state tax rate changes — — (2,587 ) Valuation allowance at end of year $ — $ — $ 4,648 The Company and certain of its subsidiaries file U.S. federal, state and foreign income tax returns. The Company is currently under a New York State income tax examination for tax years 2010 through 2017. At this time, the Company cannot estimate when the examinations will conclude or the impact such examinations will have on the Company’s Consolidated Financial Statements, if any. Generally, the Company is no longer subject to tax examinations by tax authorities for years prior to 2016. A reconciliation of the unrecognized tax benefits is as follows: Year Ended December 31, 2019 2018 2017 (In thousands) Balance at beginning of year $ 4,718 $ 2,650 $ 29 Additions attributable to state and local apportionment 2,113 2,068 2,650 Reductions for tax positions of prior years — — (29 ) Balance at end of year $ 6,831 $ 4,718 $ 2,650 As of December 31, 2019, the Company recorded $6.8 million of unrecognized tax benefits which, if recognized, would affect the Company’s effective tax rate. Due to the uncertainty related to the timing and potential outcome of audits, the Company cannot reasonably estimate the amount of the unrecognized tax benefit that could be adjusted in the next 12 months. During the years ended December 31, 2019, 2018 and 2017, the Company recognized $0.6 million, $0.4 million and $0.2 million, respectively, in penalties and interest. The Company had $1.2 million and $0.6 million accrued for the payment of interest and penalties at December 31, 2019 and 2018, respectively.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Stockholders' Equity	9 . Stockholders’ Equity Common Stock As of December 31, 2019 and 2018, 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, 2019 2018 2017 (In thousands) Outstanding shares of voting common stock at the beginning of year 37,640 37,621 37,544 Exercise of stock options 107 121 262 Issuance of restricted stock, net of shares withheld for withholding tax payments and cancellations 103 22 39 Treasury shares used for acquisition 146 — — Repurchases (60 ) (124 ) (224 ) Outstanding shares of voting common stock at the end of year 37,936 37,640 37,621 In January 2016, the Board of Directors authorized a share repurchase program for up to $25.0 million of the Company’s common stock. In October 2016, the Board of Directors approved a $50.0 million increase in the size of the repurchase program. This program expired in September 2017. In September 2017, the Board of Directors authorized a fifteen-month two-year Dividends During 2019, 2018 and 2017, the Company paid quarterly cash dividends of $0.51 per share, $0.42 per share and $0.33 per share, respectively. Any future declaration and payment of dividends will be at the sole discretion of the Company’s Board of Directors. The Board of Directors may take into account such matters as general business conditions, the Company’s financial results, capital requirements, contractual obligations, legal, and regulatory restrictions on the payment of dividends to the Company’s stockholders or by the Company’s subsidiaries to their respective parent entities, and any such other factors as the Board of Directors may deem relevant.

Stock-Based Compensation Plans

Stock-Based Compensation Plans	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation Plans	10 . Stock-Based Compensation Plans The Company maintains 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, 2019, there were 93,946 shares available for grant under the stock incentive plan. Total stock-based compensation expense was as follows: Year Ended December 31, 2019 2018 2017 (In thousands) Employees: Restricted stock and performance shares $ 20,182 $ 12,559 $ 11,566 Stock options 4,032 2,193 1,882 24,214 14,752 13,448 Non-employee directors: Restricted stock 1,080 1,098 973 Total stock-based compensation $ 25,294 $ 15,850 $ 14,421 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 The weighted-average fair value for options granted during 2019, 2018 and 2017 was $58.37, $56.11 and $40.08, 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, excluding the two awards discussed below: Year Ended December 31, 2019 2018 2017 Expected life (years) 5.0 5.0 5.0 Risk-free interest rate 2.6 % 2.2 % 1.9 % Expected volatility 25.9 % 26.9 % 28.0 % Expected dividend yield 0.8 % 0.8 % 0.8 % In addition to the option grants above, 76,868 stock options were granted to the Company’s President and Chief Operating Officer in January 2019 with an aggregate grant date fair value of $2.9 million as determined by an independent third party using a Monte Carlo simulation model. The exercise price is $272.88 for 35,679 of the stock options and $294.71 for the remaining 41,189 stock options, which is equal to 125% and 135%, respectively, of the fair market value of the Company’s common stock on the grant date. Subject to the grantee’s continued employment with the Company, the options will vest and become exercisable on January 22, 2024. The options expire on July 22, 2024. Key assumptions used for the Monte Carlo model included a risk-free interest rate of 2.6%, volatility of 25.8% and a dividend yield of 0.8%. In November 2018, 148,524 stock options were granted to the Company’s Chief Executive Officer with a grant date fair value of $5.5 million as determined by an independent third party using a Monte Carlo simulation model. The exercise price is $257.78 for 69,113 of the stock options and $278.40 for the remaining 79,411 stock options, which is equal to 125% and 135%, respectively, of the fair market value of the Company’s stock on the grant date. Subject to the grantee’s continued employment with the Company, the options will vest and become exercisable on November 8, 2023. The options expire on May 8, 2024. Key assumptions used for the Monte Carlo model included a risk-free interest rate of 3.1%, volatility of 25.9% and a dividend yield of 0.8%. The following table reports stock option activity during the three years ended December 31, 2019 and the intrinsic value as of December 31, 2019: Number of Shares Weighted-Average Exercise Price ($) Remaining Contractual Term Intrinsic Value ($) (In thousands) Outstanding at December 31, 2016 855,740 $ 36.80 Granted 54,838 156.85 Canceled — — Exercised (380,967 ) 11.26 Outstanding at December 31, 2017 529,611 67.60 Granted 168,217 261.19 Canceled (1,676 ) 142.69 Exercised (120,588 ) 24.66 Outstanding at December 31, 2018 575,564 132.93 Granted 82,474 279.57 Canceled (548 ) 198.67 Exercised (106,899 ) 28.24 $ 33,639 Outstanding at December 31, 2019 550,591 175.16 2.8 112,294 Exercisable at December 31, 2019 171,782 96.71 1.5 48,512 The intrinsic value is the amount by which the closing price of the Company’s common stock on December 31, 2019 of $379.11 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, 2019, there was $7.8 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 2.6 years. Restricted Stock and Performance Shares Restricted stock generally vests over a three or five-year The following table reports performance share activity for annual awards for the three years ended December 31, 2019: Performance year: 2019 2018 2017 Target share pay-out 16,716 10,479 12,971 Actual share pay-out (paid in following year) 19,400 10,479 8,094 Weighted average fair value per share on grant date $ 223.81 $ 202.04 $ 155.53 In addition to the grants above, 18,914 performance shares were granted to the Company’s President and Chief Operating Officer in January 2019 with an aggregate fair value of $2.9 million as determined by an independent third party using a Monte Carlo simulation model. The performance share award provides that the number of shares earned will be based on the Company’s achievement of certain share price levels during the five-year In November 2018, 37,742 performance shares were granted to the Company’s Chief Executive Officer with a grant date fair value of $5.5 million as determined by an independent third party using a Monte Carlo simulation model. The performance share award provides that the number of shares earned will be based on the Company’s achievement of certain share price levels during the five-year In April 2017, the Company granted 9,367 multi-year performance shares to a certain officer. The performance share awards are earned or forfeited based on attaining certain cumulative operating income thresholds of the Company and select subsidiaries over the two-year 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 four-year The following table reports restricted stock and performance share activity during the three years ended December 31, 2019: Number of Restricted Shares Weighted-Average Grant Date Fair Value Outstanding at December 31, 2016 383,978 $ 71.50 Granted 61,434 Performance share pay-out 21,422 Canceled (4,590 ) Vested (142,645 ) Outstanding at December 31, 2017 319,599 $ 88.77 Granted 59,179 Performance share pay-out 8,094 Canceled (4,046 ) Vested (110,956 ) Outstanding at December 31, 2018 271,870 $ 112.47 Granted 118,632 Performance share pay-out 87,163 Canceled (2,321 ) Vested (129,312 ) Outstanding at December 31, 2019 346,032 $ 154.27 As of December 31, 2019, there was $31.0 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 1.6 years. Employee Stock Purchase Plan The Company offers 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 grants 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

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share	11. Earnings Per Share The following table sets forth basic and diluted weighted average shares outstanding used to compute earnings per share: Year Ended December 31, 2019 2018 2017 (In thousands) Basic weighted average shares outstanding 37,083 36,958 36,864 Dilutive effect of stock options and restricted stock 873 897 1,174 Diluted weighted average shares outstanding 37,956 37,855 38,038 Stock options and restricted stock totaling 146,822 shares, 83,718 shares and 31,766 shares for the years ended December 31, 2019, 2018 and 2017, 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, 2019
Debt Disclosure [Abstract]
Credit Agreement	12. Credit Agreement In October 2015, the Company entered into a two-year October 2018 one-year October 2019 October 2020 Borrowings under the Credit Agreement will bear interest at a rate per annum equal to the base rate or adjusted LIBOR plus an applicable margin that varies with the Company’s consolidated total leverage ratio. The Credit Agreement requires that the Company satisfies certain covenants, which includes leverage ratios, a minimum net regulatory capital balance for certain subsidiaries and minimum earnings before interest, tax, depreciation and amortization requirements. The Company was in compliance with all applicable covenants at December 31, 2019 and December 31, 2018. 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). 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.

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	13. Leases The Company has operating leases for corporate offices with initial lease terms ranging from one-year The following table presents the components of occupancy expense for the year ended December 31, 2019: Lease cost: Classification 2019 (In thousands) Operating lease cost Occupancy $ 10,875 Operating lease cost for subleased/assigned properties Other, net 2,422 Variable lease costs Occupancy 169 Sublease income for subleased/assigned properties Other, net (2,422 ) Net lease cost $ 11,044 The Company determines whether an arrangement is, or includes, a lease at contract inception. Operating lease right-of-use assets and liabilities are recognized at commencement date and are initially measured based on the present value of lease payments over the defined lease term. As the Company’s leases do not provide an implicit rate, the Company used its incremental borrowing rate based on the information available at the adoption date in determining the present value of lease payments. The weighted average remaining lease term and weighted average discount rate were 13.3 years and 5.9%, respectively, for operating leases as of December 31, 2019. The following table presents the maturity of lease liabilities as of December 31, 2019: (In thousands) 2020 $ 10,955 2021 11,667 2022 10,379 2023 10,149 2024 10,816 2025 and thereafter 89,690 Total lease payments 143,656 Less: interest 45,665 Present value of lease liabilities $ 97,991 Minimum lease commitments as of December 31, 2018 that had an initial term or remaining lease term in excess of one-year are as follows: (In thousands) 2019 $ 9,764 2020 10,919 2021 10,114 2022 9,067 2023 8,738 2024 and thereafter 95,467 $ 144,069 In September 2019, the Company entered into a lease agreement for approximately 15,646 square feet of office space in London, which commenced on December 1, 2019 and expires on January 15, 2027. At commencement, the aggregate minimum rental commitment under such lease was $8.3 million. The Company recorded a new right-of-use asset and corresponding lease liability of approximately $7.0 million. The Company has entered into agreements that assign the Company’s lease obligations on two properties to third parties and is contingently liable should the third parties default on future lease obligations through the lease termination dates of November 2020 and February 2022. The aggregate amount of the future lease obligations under these arrangements is $3.8 million as of December 31, 2019.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	14. Commitments and Contingencies 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 certain of its subsidiaries, executes 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 two trading days after the trade date. Cash settlement of the transaction occurs upon receipt or delivery of the underlying instrument that was traded. 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, 2019 and 2018, the amount of the collateral deposits, which are disclosed in the Consolidated Statements of Cash Flows as restricted cash, and included in prepaid expenses and other assets in the Consolidated Statements of Financial Condition was $4.1 million and $1.1 million, respectively. 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 third-party 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, 2019, 2018 and 2017. 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, 2019
Segment Reporting [Abstract]
Segment and Geographic Information	15. 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 For the years ended December 31, 2019, 2018 and 2017, 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. Information regarding revenue for the three years ended December 31, 2019, 2018 and 2017 and long-lived assets as of December 31, 2019 and 2018 follows: Year Ended December 31, 2019 2018 2017 (In thousands) Revenues United States $ 424,731 $ 367,373 $ 332,982 United Kingdom 84,076 66,241 58,991 Other 2,545 1,951 1,449 Total $ 511,352 $ 435,565 $ 393,422 As of December 31, 2019 2018 (In thousands) Long-lived assets, as defined United States $ 62,356 $ 55,200 United Kingdom 9,410 7,787 Other 29 23 Total $ 71,795 $ 63,010

Retirement and Deferred Compens

Retirement and Deferred Compensation Plans	12 Months Ended
	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Retirement and Deferred Compensation Plans	16. 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, 2019, 2018 and 2017, the Company contributed $3.3 million, $2.6 million and $1.8 million, respectively, to the plans. The Company offers a non-qualified deferred cash incentive plan to 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. As of December 31, 2019 and 2018, the fair value of the mutual fund investments and deferred compensation obligations were $6.2 million and $4.1 million, respectively. Changes in the fair value of securities held in the rabbi trust and offsetting increases or decreases in the deferred compensation obligation are recognized in other, net in the Company’s Consolidated Statements of Operations.

Parent Company Information

Parent Company Information	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Parent Company Information	17. Parent Company Information The following tables present Parent Company–only financial information and should be read in conjunction with the consolidated financial statements of the Company. MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Financial Condition As of December 31, 2019 December 31, 2018 (In thousands) ASSETS Cash and cash equivalents $ 48,241 $ 95,840 Investments, at fair value 141,318 149,266 Accounts receivable 63 59 Receivable from subsidiaries 5,997 — Intangible assets, net of accumulated amortization 30 — Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization 25,247 25,742 Operating lease right-of-use assets 68,559 — Investments in subsidiaries 570,145 356,363 Prepaid expenses and other assets 3,506 4,439 Deferred tax assets, net 3,472 5,039 Income and other tax receivable 3,219 — Total assets $ 869,797 $ 636,748 LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities Accrued employee compensation $ 6,543 $ 5,667 Income and other tax liabilities — 2,612 Payable to subsidiaries — 3 Accounts payable, accrued expenses and other liabilities 9,254 20,588 Operating lease liabilities 83,909 — Total liabilities 99,706 28,870 Stockholders' equity Preferred stock — — Series A Preferred Stock — — Common stock voting 122 122 Common stock non-voting — — Additional paid-in capital 342,541 341,860 Treasury stock (153,388 ) (184,962 ) Retained earnings 591,086 463,252 Accumulated other comprehensive loss (10,270 ) (12,394 ) Total stockholders' equity 770,091 607,878 Total liabilities and stockholders' equity $ 869,797 $ 636,748 MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Operations and Comprehensive Income Year Ended December 31, 2019 2018 2017 (In thousands) Dividends from subsidiary $ 165,000 $ 130,000 $ 120,000 Expenses Employee compensation and benefits 16,100 10,785 11,289 Depreciation and amortization 1,919 1,760 1,971 Technology and communications 13 43 41 Professional and consulting fees 6,523 4,932 4,185 Occupancy 850 7,381 143 General and administrative 2,252 1,513 852 Total expenses 27,657 26,414 18,481 Operating income 137,343 103,586 101,519 Other income (expense) Investment income 5,305 3,835 2,608 Other, net (1,344 ) (711 ) (685 ) Total other income 3,961 3,124 1,923 Income before income taxes and equity in undistributed income of subsidiaries 141,304 106,710 103,442 Provision for income taxes (9,442 ) (7,350 ) (13,935 ) Income before equity in undistributed income of subsidiaries 150,746 114,060 117,377 Equity in undistributed income of subsidiaries 54,156 58,792 30,712 Net income 204,902 172,852 148,089 Other comprehensive income (loss), net 2,124 (2,168 ) 2,002 Comprehensive income $ 207,026 $ 170,684 $ 150,091 MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Cash Flows Year Ended December 31, 2019 2018 2017 (In thousands) Cash flows from operating activities Net income $ 204,902 $ 172,852 $ 148,089 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation and amortization 1,919 1,760 1,971 Amortization of operating lease right-of-use assets 4,027 — — Stock-based compensation expense 21,800 14,257 13,071 Deferred taxes 1,255 (2,515 ) 5,004 Equity in undistributed income of subsidiaries (54,156 ) (58,792 ) (30,712 ) Other 328 710 1,581 Changes in operating assets and liabilities: (Increase) decrease in accounts receivable (4 ) (14 ) 205 (Increase) decrease in receivable from subsidiaries (6,000 ) 7,529 17,518 Decrease (increase) in prepaid expenses and other assets 933 (782 ) 687 (Increase) in mutual funds held in rabbi trust (1,183 ) (470 ) (949 ) Increase in accrued employee compensation 876 567 607 (Increase) in income and other tax receivable (3,219 ) — — (Decrease) increase in income and other tax liabilities (2,612 ) 469 (825 ) (Decrease) increase in accounts payable, accrued expenses and other liabilities (2,039 ) 13,619 (261 ) Increase in operating lease liabilities 1,191 — — Net cash provided by operating activities 168,018 149,190 155,986 Cash flows from investing activities Acquisition of business, net of cash and cash equivalents acquired (102,320 ) — — Repayment from subsidiary — — 5,000 Available-for-sale investments Proceeds from maturities and sales 170,936 333,791 187,794 Purchases (160,827 ) (336,533 ) (215,831 ) Purchases of furniture, equipment and leasehold improvements (1,424 ) (24,786 ) (2,160 ) Purchase of intangible asset (30 ) — — Net cash (used in) investing activities (93,665 ) (27,528 ) (25,197 ) Cash flows from financing activities Cash dividend on common stock (76,231 ) (62,432 ) (48,888 ) Exercise of stock options 1,207 2,973 1,972 Withholding tax payments on restricted stock vesting and stock option exercises (25,820 ) (8,043 ) (27,691 ) Repurchases of common stock (17,256 ) (25,171 ) (42,461 ) Net cash (used in) financing activities (118,100 ) (92,673 ) (117,068 ) Effect of exchange rate changes on investments (3,852 ) 4,129 (4,687 ) Cash and cash equivalents including restricted cash Net (decrease) increase for the period (47,599 ) 33,118 9,034 Beginning of period 95,840 62,722 53,688 End of period $ 48,241 $ 95,840 $ 62,722 Supplemental cash flow information: Cash paid during the year for income taxes $ 41,025 $ 37,721 $ 37,769 Non-cash investing and financing activity: Treasury stock used for acquisition of business $ (48,830 ) $ — $ —

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
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.
Accounting Pronouncements, Recently Adopted	Accounting Pronouncements, Recently Adopted In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-15, “Intangibles—Goodwill and Other—Internal-Use Software: Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract” (“ASU 2018-15”). The standard requires the capitalization of implementation costs incurred in a cloud computing arrangement to be aligned with the requirements for capitalizing costs incurred to develop or obtain internal use software. The updated guidance is effective for annual and interim reporting periods beginning after December 15, 2019, with early adoption permitted. The Company adopted ASU 2018-15 effective July 1, 2019 on a prospective basis. The Company completed its analysis and the adoption of this guidance did not have a material impact 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 with lease terms greater than 12 months. The Company adopted ASU 2016-02 effective January 1, 2019 using a modified retrospective transition approach and will not restate comparative periods. In addition, the Company elected the package of practical expedients permitted under the transition guidance within the new standard which allowed it to carry forward the historical lease classification. In May 2014, the FASB issued 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 also requires new disclosure concerning contracts with customers, including the significant judgments made when applying the guidance. The Company adopted ASU 2014-09 effective January 1, 2018 using the modified retrospective transition approach. The adoption of this guidance did not have a material impact on the Company’s Consolidated Financial Statements.
Accounting Pronouncements, Not Yet Adopted as of December 31, 2019	Accounting Pronouncements, Not Yet Adopted as of December 31, 2019 In January 2017, the FASB issued ASU 2017-04, “Intangibles-Goodwill and Other” (“ASU 2017-04”). ASU 2017-04 simplifies the testing for goodwill impairment. The guidance will be effective for the Company beginning January 1, 2020 and early adoption is permitted and should be applied prospectively. The adoption of this guidance is not expected to have a material effect on the Company’s Consolidated Financial Statements.
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 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 include investment grade corporate debt securities and U.S. Treasuries and are carried at fair value, with realized and unrealized gains or losses included in other, net 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, 2019, 2018 and 2017.
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 $0.2 million as of December 31, 2019, 2018 and 2017, respectively. The provision for bad debts was $0.3 million, $0.2 million and $0.4 million for the years ended December 31, 2019, 2018 and 2017, respectively. Write-offs and other charges against the allowance for doubtful accounts were $0.1 million, $0.2 million and $0.1 million for the years ended December 31, 2019, 2018 and 2017, 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.
Cloud Computing Costs	Cloud Computing Costs The Company capitalizes certain costs associated with cloud computing arrangements, including, among other items, employee compensation and related benefits and third-party consulting costs that are part of the application development stage. These costs are setup as a prepaid asset on the balance sheet and are amortized over the period of the hosting service contract. 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 other, net 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 Company’s classification of revenues in the Consolidated Statements of Operations represents revenues from contracts with customers disaggregated by type of revenue. The Company has four revenue streams as described below. Commission Revenue. The Company charges its broker-dealer clients variable transaction fees for trades executed on its platform and, under certain plans, distribution fees or monthly minimum fees to use the platform for a particular product area. Variable transaction fees 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 disclosed trading transaction fee plans, bonds that are more actively traded or that have shorter maturities generally generate lower commissions, while bonds that are less actively traded or that have longer maturities generally command higher commissions. Variable transaction fees, distribution fees and unused monthly fee commitments are invoiced and recorded on a monthly basis. For Open Trading 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 its commission through the difference in price between the two trades. The commission is collected upon settlement of the trade, which typically occurs within one to two trading days after the trade date. For U.S. Treasury matched principal trades, commissions are invoiced and recorded on a monthly basis. The following table presents commission revenue by fee type: Year Ended December 31, 2019 2018 2017 (In thousands) Commission revenue by fee type Variable transaction fees Disclosed trading $ 266,916 $ 228,004 $ 234,143 Open Trading - matched principal trading 98,080 65,932 45,660 U.S. Treasuries - matched principal trading 2,184 — — Total variable transaction fees 367,180 293,936 279,803 Distribution fees and unused minimum fees 96,676 96,898 75,479 Total commissions $ 463,856 $ 390,834 $ 355,282 Information services – Information services includes data licensed to the Company’s broker-dealer clients, institutional investor clients and data-only subscribers; professional and consulting services; technology software licenses; and maintenance and support services. The nature and timing of each performance obligation may vary as these contracts are either subscription - based services transferred over time , and may be net of volume -based discounts , or one-time services that are transferred at a point in time. Revenues for services transferred over time are recognized ratably over the contract period as the Company’s performance obligation is met whereas revenues for services transferred at a point in time are recognized in the period the services are provided. Customers are generally billed monthly, quarterly, or annually; revenues billed in advance are deferred and recognized ratably over the contract period. The following table presents information services revenue by timing of recognition: Year Ended December 31, 2019 2018 2017 (In thousands) Information services revenue by timing of recognition Services transferred over time $ 29,619 $ 27,475 $ 25,242 Services transferred at a point in time 1,111 752 564 Total information services revenues $ 30,730 $ 28,227 $ 25,806 Post-trade services – Post-trade services revenue is generated from regulatory transaction reporting, trade publication and trade matching services. Customers are generally billed monthly in arrears and revenue is recognized in the period transactions are processed. Revenues billed in advance are deferred and recognized ratably over the contract period. The Company also generates one-time implementation fees for onboarding clients which are invoiced and recognized in the period the implementation is completed. The following table presents post-trade services revenue by timing of recognition: Year Ended December 31, 2019 2018 2017 (In thousands) Post-trade services revenue by timing of recognition Services transferred over time $ 15,669 $ 15,013 $ 9,657 Services transferred at a point in time 94 333 1,433 Total post-trade services revenues $ 15,763 $ 15,346 $ 11,090 Other revenues – Other revenues primarily includes revenue from telecommunications line charges to broker-dealer clients. Contract liabilities consist of deferred revenues that the Company records when cash payments are received or due in advance of services to be performed. The revenue recognized from contract liabilities and the remaining balance is shown below: December 31, 2018 Payments received in advance of services to be performed Revenue recognized for services performed during the period Foreign Currency Translation December 31, 2019 (In thousands) Information services $ 1,959 $ 7,439 $ (7,260 ) $ — $ 2,138 Post-trade services 851 13,617 (13,136 ) 29 1,361 Total deferred revenue $ 2,810 $ 21,056 $ (20,396 ) $ 29 $ 3,499 The majority of the Company’s contracts are short-term in nature with durations of less than one-year. For contracts extending beyond one year, the aggregate amount of the transaction price allocated to remaining performance obligations was $41.7 million as of December 31, 2019. The Company expects to recognize revenue associated with the remaining performance obligations over the next 31 months.
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. Forfeitures are recognized as they occur.
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 other, net in the Consolidated Statements of Operations. All tax effects related to share-based payments are recorded through tax expense in the periods during which the awards are exercised or vest.
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, customer attrition 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 over their estimated useful lives which range from one to 15 years using either a straight-line or accelerated amortization method based on the pattern of economic benefit the Company expects to realize from such assets. 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 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.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Commission Revenue by Fee Type	The following table presents commission revenue by fee type: Year Ended December 31, 2019 2018 2017 (In thousands) Commission revenue by fee type Variable transaction fees Disclosed trading $ 266,916 $ 228,004 $ 234,143 Open Trading - matched principal trading 98,080 65,932 45,660 U.S. Treasuries - matched principal trading 2,184 — — Total variable transaction fees 367,180 293,936 279,803 Distribution fees and unused minimum fees 96,676 96,898 75,479 Total commissions $ 463,856 $ 390,834 $ 355,282
Summary of Information Services Revenue by Timing of Recognition	The following table presents information services revenue by timing of recognition: Year Ended December 31, 2019 2018 2017 (In thousands) Information services revenue by timing of recognition Services transferred over time $ 29,619 $ 27,475 $ 25,242 Services transferred at a point in time 1,111 752 564 Total information services revenues $ 30,730 $ 28,227 $ 25,806
Summary of Post-Trade Services Revenue by Timing of Recognition	The following table presents post-trade services revenue by timing of recognition: Year Ended December 31, 2019 2018 2017 (In thousands) Post-trade services revenue by timing of recognition Services transferred over time $ 15,669 $ 15,013 $ 9,657 Services transferred at a point in time 94 333 1,433 Total post-trade services revenues $ 15,763 $ 15,346 $ 11,090
Summary of Revenue Recognized from Contract Liabilities and Remaining Balance	The revenue recognized from contract liabilities and the remaining balance is shown below: December 31, 2018 Payments received in advance of services to be performed Revenue recognized for services performed during the period Foreign Currency Translation December 31, 2019 (In thousands) Information services $ 1,959 $ 7,439 $ (7,260 ) $ — $ 2,138 Post-trade services 851 13,617 (13,136 ) 29 1,361 Total deferred revenue $ 2,810 $ 21,056 $ (20,396 ) $ 29 $ 3,499

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2019
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 (In thousands) As of December 31, 2019 Money market funds $ 99,755 $ — $ — $ 99,755 Securities available-for-sale Corporate debt — 137,835 — 137,835 Trading securities Corporate debt — 31,120 — 31,120 U.S. Treasuries — 55,305 — 55,305 Mutual funds held in rabbi trust — 6,217 — 6,217 Foreign currency forward position — (2,772 ) — (2,772 ) Total $ 99,755 $ 227,705 $ — $ 327,460 As of December 31, 2018 Money market funds $ 112,529 $ — $ — $ 112,529 Securities available-for-sale Corporate debt — 146,966 — 146,966 Trading securities Corporate debt — 71,861 — 71,861 U.S. Treasuries — 17,178 — 17,178 Mutual funds held in rabbi trust — 4,100 — 4,100 Foreign currency forward position — (1,021 ) — (1,021 ) Total $ 112,529 $ 239,084 $ — $ 351,613
Summary of Foreign Currency Forward Contracts	A summary of the foreign currency forward position is as follows: As of December 31, 2019 2018 (In thousands) Notional value $ 155,885 $ 106,306 Fair value of notional 158,657 107,327 Fair value of the (liability) $ (2,772 ) $ (1,021 )
Summary of Company's Investments	The following is a summary of the Company’s investments: Amortized cost Gross unrealized gains Gross unrealized losses Estimated fair value (In thousands) As of December 31, 2019 Securities available-for-sale Corporate debt $ 137,119 $ 721 $ (5 ) $ 137,835 Trading securities Corporate debt 31,120 14 (14 ) 31,120 U.S. Treasuries 54,738 567 — 55,305 Mutual funds held in rabbi trust 5,173 1,044 — 6,217 Total trading securities 91,031 1,625 (14 ) 92,642 Total investments $ 228,150 $ 2,346 $ (19 ) $ 230,477 As of December 31, 2018 Securities available-for-sale Corporate debt $ 147,556 $ 27 $ (617 ) $ 146,966 Trading securities Corporate debt 72,274 8 (421 ) 71,861 U.S. Treasuries 16,953 225 — 17,178 Mutual funds held in rabbi trust 4,347 — (247 ) 4,100 Total trading securities 93,574 233 (668 ) 93,139 Total investments $ 241,130 $ 260 $ (1,285 ) $ 240,105
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, 2019 2018 (In thousands) Less than one year $ 120,850 $ 134,255 Due in 1 - 5 years 109,627 105,850 Total $ 230,477 $ 240,105
Fair Values and Unrealized Losses on Corporate Debt Investments	The following table provides fair values and unrealized losses on corporate debt investments and by the aging of the securities' continuous unrealized loss position as of December 31, 2019 and 2018 respectively: Less than Twelve Months Twelve Months or More Total Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses (In thousands) As of December 31, 2019 Corporate debt $ 27,999 $ (18 ) $ 4,406 $ (1 ) $ 32,405 $ (19 ) As of December 31, 2018 Corporate debt $ 80,282 $ (256 ) $ 87,028 $ (782 ) $ 167,310 $ (1,038 )

Acquisition (Tables)

Acquisition (Tables)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Summary of Preliminary Purchase Price Allocation	The Company has completed a preliminary allocation of the purchase price to the fair value of assets acquired and liabilities assumed at the date of acquisition. The Company utilized an independent third-party to determine the fair value of the acquired intangible assets. It is possible that the purchase price allocation will be adjusted upon finalization of the accounting for the acquired assets. The preliminary purchase price allocation is as follows (in thousands): Purchase price $ 152,677 Less: acquired cash (2,935 ) Purchase price, net of acquired cash 149,742 Accounts receivable (1,811 ) Intangible assets (58,780 ) Prepaid expenses and other assets (4,168 ) Accounts payable, accrued expenses and other liabilities 2,165 Goodwill $ 87,148
Summary of Acquired Intangible Assets	The acquired intangible assets are as follows (in thousands, except for useful lives): Costs Useful Lives Customer relationships $ 58,690 15 years Tradename - finite life 90 1 year Total $ 58,780

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Changes in Goodwill and Intangible Assets with Indefinite Lives	The following is a summary of changes in goodwill and intangible assets with indefinite lives for the year ended December 31, 2019 (in thousands): Balance at beginning of period $ 59,713 Goodwill from LiquidityEdge acquisition 87,148 Balance at end of period $ 146,861
Summary of Company's Intangible Assets	Intangible assets that are subject to amortization, including the related accumulated amortization, are comprised of the following: December 31, 2019 December 31, 2018 Cost Accumulated amortization Net carrying amount Cost Accumulated amortization Net carrying amount (In thousands) Technology $ 5,770 $ (5,770 ) $ — $ 5,770 $ (5,770 ) $ — Customer relationships 64,332 (3,451 ) 60,881 5,634 (2,672 ) 2,962 Non-competition agreements 380 (380 ) — 380 (380 ) — Tradenames and patents 490 (385 ) 105 370 (370 ) — Total $ 70,972 $ (9,986 ) $ 60,986 $ 12,154 $ (9,192 ) $ 2,962

Capitalized Software, Furnitu_2

Capitalized Software, Furniture, Equipment and Leasehold Improvements (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 2018 (In thousands) Software development costs $ 119,911 $ 97,113 Computer hardware and related software 48,379 42,705 Office hardware 5,725 5,909 Furniture and fixtures 5,000 5,385 Leasehold improvements 27,966 32,527 206,981 183,639 Accumulated depreciation and amortization (135,186 ) (120,629 ) Total $ 71,795 $ 63,010

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of Provision for Income Taxes	The provision for income taxes consists of the following: Year Ended December 31, 2019 2018 2017 (In thousands) Current: Federal $ 28,928 $ 31,617 $ 36,045 State and local 7,686 5,928 3,848 Foreign 13,234 8,862 7,234 Total current provision 49,848 46,407 47,127 Deferred: Federal 2,579 (1,416 ) 6,171 State and local 403 (272 ) 661 Foreign (308 ) 515 (280 ) Total deferred provision 2,674 (1,173 ) 6,552 Provision for income taxes $ 52,522 $ 45,234 $ 53,679
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 21% is as follows: Year Ended December 31, 2019 2018 2017 U.S. federal tax at statutory rate 21.0 % 21.0 % 35.0 % State and local taxes - net of federal benefit 2.5 2.0 1.5 Credits and deductions related to research activities (0.3 ) (0.3 ) (1.2 ) Foreign rate differential benefit (0.5 ) (0.5 ) (2.9 ) Excess tax benefit from stock-based compensation (3.5 ) (2.1 ) (11.6 ) Tax Cuts and Jobs Act provisional tax charge — (0.2 ) 5.8 Other, net 1.2 0.8 — Provision for income taxes 20.4 % 20.7 % 26.6 %
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, 2019 2018 (In thousands) Deferred tax assets: Stock compensation expense $ 4,926 $ 4,967 Operating lease liabilities 20,227 — Other 892 3,569 Total deferred tax assets 26,045 8,536 Valuation allowance — — Net deferred tax assets 26,045 8,536 Deferred tax liabilities: Depreciation and amortization (4,085 ) (1,847 ) Capitalized software development costs (5,306 ) (3,776 ) Goodwill and intangible assets (1,120 ) (898 ) Operating lease right-of-use assets (16,515 ) — Deferred tax (liability) asset, net $ (981 ) $ 2,015
Summary of Changes in Valuation Allowance	A summary of the changes in the valuation allowance is as follows: Year Ended December 31, 2019 2018 2017 (In thousands) Valuation allowance at beginning of year $ — $ 4,648 $ 7,235 (Decrease) to valuation allowance attributable to: Expiration of capital loss carryforwards — (4,648 ) — Federal and state tax rate changes — — (2,587 ) Valuation allowance at end of year $ — $ — $ 4,648
Reconciliation of the Unrecognized Tax Benefits	A reconciliation of the unrecognized tax benefits is as follows: Year Ended December 31, 2019 2018 2017 (In thousands) Balance at beginning of year $ 4,718 $ 2,650 $ 29 Additions attributable to state and local apportionment 2,113 2,068 2,650 Reductions for tax positions of prior years — — (29 ) Balance at end of year $ 6,831 $ 4,718 $ 2,650

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Summary of the Change in the Company's Outstanding Shares of Common Stock	The following is a summary of the change in the Company’s outstanding shares of voting common stock: Year Ended December 31, 2019 2018 2017 (In thousands) Outstanding shares of voting common stock at the beginning of year 37,640 37,621 37,544 Exercise of stock options 107 121 262 Issuance of restricted stock, net of shares withheld for withholding tax payments and cancellations 103 22 39 Treasury shares used for acquisition 146 — — Repurchases (60 ) (124 ) (224 ) Outstanding shares of voting common stock at the end of year 37,936 37,640 37,621

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation Expense	Total stock-based compensation expense was as follows: Year Ended December 31, 2019 2018 2017 (In thousands) Employees: Restricted stock and performance shares $ 20,182 $ 12,559 $ 11,566 Stock options 4,032 2,193 1,882 24,214 14,752 13,448 Non-employee directors: Restricted stock 1,080 1,098 973 Total stock-based compensation $ 25,294 $ 15,850 $ 14,421
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, excluding the two awards discussed below: Year Ended December 31, 2019 2018 2017 Expected life (years) 5.0 5.0 5.0 Risk-free interest rate 2.6 % 2.2 % 1.9 % Expected volatility 25.9 % 26.9 % 28.0 % Expected dividend yield 0.8 % 0.8 % 0.8 %
Stock Option Activity	The following table reports stock option activity during the three years ended December 31, 2019 and the intrinsic value as of December 31, 2019: Number of Shares Weighted-Average Exercise Price ($) Remaining Contractual Term Intrinsic Value ($) (In thousands) Outstanding at December 31, 2016 855,740 $ 36.80 Granted 54,838 156.85 Canceled — — Exercised (380,967 ) 11.26 Outstanding at December 31, 2017 529,611 67.60 Granted 168,217 261.19 Canceled (1,676 ) 142.69 Exercised (120,588 ) 24.66 Outstanding at December 31, 2018 575,564 132.93 Granted 82,474 279.57 Canceled (548 ) 198.67 Exercised (106,899 ) 28.24 $ 33,639 Outstanding at December 31, 2019 550,591 175.16 2.8 112,294 Exercisable at December 31, 2019 171,782 96.71 1.5 48,512
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, 2019: Performance year: 2019 2018 2017 Target share pay-out 16,716 10,479 12,971 Actual share pay-out (paid in following year) 19,400 10,479 8,094 Weighted average fair value per share on grant date $ 223.81 $ 202.04 $ 155.53
Restricted Stock and Performance Share Activity	The following table reports restricted stock and performance share activity during the three years ended December 31, 2019: Number of Restricted Shares Weighted-Average Grant Date Fair Value Outstanding at December 31, 2016 383,978 $ 71.50 Granted 61,434 Performance share pay-out 21,422 Canceled (4,590 ) Vested (142,645 ) Outstanding at December 31, 2017 319,599 $ 88.77 Granted 59,179 Performance share pay-out 8,094 Canceled (4,046 ) Vested (110,956 ) Outstanding at December 31, 2018 271,870 $ 112.47 Granted 118,632 Performance share pay-out 87,163 Canceled (2,321 ) Vested (129,312 ) Outstanding at December 31, 2019 346,032 $ 154.27

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Basic and Diluted Weighted Average Shares Outstanding Used to Compute Earnings Per Share	The following table sets forth basic and diluted weighted average shares outstanding used to compute earnings per share: Year Ended December 31, 2019 2018 2017 (In thousands) Basic weighted average shares outstanding 37,083 36,958 36,864 Dilutive effect of stock options and restricted stock 873 897 1,174 Diluted weighted average shares outstanding 37,956 37,855 38,038

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Schedule of Components of Occupancy Expense	The following table presents the components of occupancy expense for the year ended December 31, 2019: Lease cost: Classification 2019 (In thousands) Operating lease cost Occupancy $ 10,875 Operating lease cost for subleased/assigned properties Other, net 2,422 Variable lease costs Occupancy 169 Sublease income for subleased/assigned properties Other, net (2,422 ) Net lease cost $ 11,044
Schedule of Maturity of Lease Liabilities	The following table presents the maturity of lease liabilities as of December 31, 2019: (In thousands) 2020 $ 10,955 2021 11,667 2022 10,379 2023 10,149 2024 10,816 2025 and thereafter 89,690 Total lease payments 143,656 Less: interest 45,665 Present value of lease liabilities $ 97,991
Summary of Minimum Lease Commitments	Minimum lease commitments as of December 31, 2018 that had an initial term or remaining lease term in excess of one-year are as follows: (In thousands) 2019 $ 9,764 2020 10,919 2021 10,114 2022 9,067 2023 8,738 2024 and thereafter 95,467 $ 144,069

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Summary of Revenue and Long-lived Assets	Information regarding revenue for the three years ended December 31, 2019, 2018 and 2017 and long-lived assets as of December 31, 2019 and 2018 follows: Year Ended December 31, 2019 2018 2017 (In thousands) Revenues United States $ 424,731 $ 367,373 $ 332,982 United Kingdom 84,076 66,241 58,991 Other 2,545 1,951 1,449 Total $ 511,352 $ 435,565 $ 393,422 As of December 31, 2019 2018 (In thousands) Long-lived assets, as defined United States $ 62,356 $ 55,200 United Kingdom 9,410 7,787 Other 29 23 Total $ 71,795 $ 63,010

Parent Company Information (Tab

Parent Company Information (Tables)	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Condensed Statements of Financial Condition	MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Financial Condition As of December 31, 2019 December 31, 2018 (In thousands) ASSETS Cash and cash equivalents $ 48,241 $ 95,840 Investments, at fair value 141,318 149,266 Accounts receivable 63 59 Receivable from subsidiaries 5,997 — Intangible assets, net of accumulated amortization 30 — Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization 25,247 25,742 Operating lease right-of-use assets 68,559 — Investments in subsidiaries 570,145 356,363 Prepaid expenses and other assets 3,506 4,439 Deferred tax assets, net 3,472 5,039 Income and other tax receivable 3,219 — Total assets $ 869,797 $ 636,748 LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities Accrued employee compensation $ 6,543 $ 5,667 Income and other tax liabilities — 2,612 Payable to subsidiaries — 3 Accounts payable, accrued expenses and other liabilities 9,254 20,588 Operating lease liabilities 83,909 — Total liabilities 99,706 28,870 Stockholders' equity Preferred stock — — Series A Preferred Stock — — Common stock voting 122 122 Common stock non-voting — — Additional paid-in capital 342,541 341,860 Treasury stock (153,388 ) (184,962 ) Retained earnings 591,086 463,252 Accumulated other comprehensive loss (10,270 ) (12,394 ) Total stockholders' equity 770,091 607,878 Total liabilities and stockholders' equity $ 869,797 $ 636,748
Condensed Statements of Operations and Comprehensive Income	MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Operations and Comprehensive Income Year Ended December 31, 2019 2018 2017 (In thousands) Dividends from subsidiary $ 165,000 $ 130,000 $ 120,000 Expenses Employee compensation and benefits 16,100 10,785 11,289 Depreciation and amortization 1,919 1,760 1,971 Technology and communications 13 43 41 Professional and consulting fees 6,523 4,932 4,185 Occupancy 850 7,381 143 General and administrative 2,252 1,513 852 Total expenses 27,657 26,414 18,481 Operating income 137,343 103,586 101,519 Other income (expense) Investment income 5,305 3,835 2,608 Other, net (1,344 ) (711 ) (685 ) Total other income 3,961 3,124 1,923 Income before income taxes and equity in undistributed income of subsidiaries 141,304 106,710 103,442 Provision for income taxes (9,442 ) (7,350 ) (13,935 ) Income before equity in undistributed income of subsidiaries 150,746 114,060 117,377 Equity in undistributed income of subsidiaries 54,156 58,792 30,712 Net income 204,902 172,852 148,089 Other comprehensive income (loss), net 2,124 (2,168 ) 2,002 Comprehensive income $ 207,026 $ 170,684 $ 150,091
Condensed Statements of Cash Flows	MarketAxess Holdings Inc. (Parent Company Only) Condensed Statements of Cash Flows Year Ended December 31, 2019 2018 2017 (In thousands) Cash flows from operating activities Net income $ 204,902 $ 172,852 $ 148,089 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation and amortization 1,919 1,760 1,971 Amortization of operating lease right-of-use assets 4,027 — — Stock-based compensation expense 21,800 14,257 13,071 Deferred taxes 1,255 (2,515 ) 5,004 Equity in undistributed income of subsidiaries (54,156 ) (58,792 ) (30,712 ) Other 328 710 1,581 Changes in operating assets and liabilities: (Increase) decrease in accounts receivable (4 ) (14 ) 205 (Increase) decrease in receivable from subsidiaries (6,000 ) 7,529 17,518 Decrease (increase) in prepaid expenses and other assets 933 (782 ) 687 (Increase) in mutual funds held in rabbi trust (1,183 ) (470 ) (949 ) Increase in accrued employee compensation 876 567 607 (Increase) in income and other tax receivable (3,219 ) — — (Decrease) increase in income and other tax liabilities (2,612 ) 469 (825 ) (Decrease) increase in accounts payable, accrued expenses and other liabilities (2,039 ) 13,619 (261 ) Increase in operating lease liabilities 1,191 — — Net cash provided by operating activities 168,018 149,190 155,986 Cash flows from investing activities Acquisition of business, net of cash and cash equivalents acquired (102,320 ) — — Repayment from subsidiary — — 5,000 Available-for-sale investments Proceeds from maturities and sales 170,936 333,791 187,794 Purchases (160,827 ) (336,533 ) (215,831 ) Purchases of furniture, equipment and leasehold improvements (1,424 ) (24,786 ) (2,160 ) Purchase of intangible asset (30 ) — — Net cash (used in) investing activities (93,665 ) (27,528 ) (25,197 ) Cash flows from financing activities Cash dividend on common stock (76,231 ) (62,432 ) (48,888 ) Exercise of stock options 1,207 2,973 1,972 Withholding tax payments on restricted stock vesting and stock option exercises (25,820 ) (8,043 ) (27,691 ) Repurchases of common stock (17,256 ) (25,171 ) (42,461 ) Net cash (used in) financing activities (118,100 ) (92,673 ) (117,068 ) Effect of exchange rate changes on investments (3,852 ) 4,129 (4,687 ) Cash and cash equivalents including restricted cash Net (decrease) increase for the period (47,599 ) 33,118 9,034 Beginning of period 95,840 62,722 53,688 End of period $ 48,241 $ 95,840 $ 62,722 Supplemental cash flow information: Cash paid during the year for income taxes $ 41,025 $ 37,721 $ 37,769 Non-cash investing and financing activity: Treasury stock used for acquisition of business $ (48,830 ) $ — $ —

Organization and Principal Bu_2

Organization and Principal Business Activity - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019Institutional_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	1,700

Significant Accounting Polici_4

Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)Revenue	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Significant Accounting Policies [Line Items]
Operating lease liabilities	$ 97,991,000
Operating lease right-of-use assets	$ 81,399,000
Maximum maturity period for classification of investments as cash equivalents	3 months
Investments other-than-temporary losses	$ 0	$ 0	$ 0
Allowance for doubtful accounts	57,000	80,000	200,000
Provision for bad debts	300,000	200,000	400,000
Write-offs and other charges against the allowance for doubtful accounts	$ 100,000	$ 200,000	$ 100,000
Number of revenue streams | Revenue	4
Description of commission revenue	For Open Trading 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 its commission through the difference in price between the two trades.
Settlement days of bond transaction	within one to two trading days
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	1 year
Minimum [Member] | Internally Developed Software [Member]
Significant Accounting Policies [Line Items]
Estimated life of intangible assets	3 years
ASU 2016-02
Significant Accounting Policies [Line Items]
Operating lease liabilities	$ 91,200,000
Operating lease right-of-use assets	79,500,000
Deferred rent liability	$ 11,700,000

Significant Accounting Polici_5

Significant Accounting Policies - Summary of Commission Revenue by Fee Type (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Commission revenue by fee type
Revenues	$ 511,352	$ 435,565	$ 393,422
Commissions [Member]
Commission revenue by fee type
Disclosed trading	266,916	228,004	234,143
Matched principal trading	98,080	65,932	45,660
Total variable transaction fees	367,180	293,936	279,803
Distribution fees and unused minimum fees	96,676	96,898	75,479
Revenues	463,856	$ 390,834	$ 355,282
Commissions [Member] | U.S. Treasuries [Member]
Commission revenue by fee type
Matched principal trading	$ 2,184

Significant Accounting Polici_6

Significant Accounting Policies - Summary of Information Services Revenue by Timing of Recognition (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Significant Accounting Policies [Line Items]
Revenues	$ 511,352	$ 435,565	$ 393,422
Information Services [Member]
Significant Accounting Policies [Line Items]
Revenues	30,730	28,227	25,806
Information Services [Member] | Transferred over Time [Member]
Significant Accounting Policies [Line Items]
Revenues	29,619	27,475	25,242
Information Services [Member] | Transferred at a Point in Time [Member]
Significant Accounting Policies [Line Items]
Revenues	$ 1,111	$ 752	$ 564

Significant Accounting Polici_7

Significant Accounting Policies - Summary of Post-Trade Services Revenue by Timing of Recognition (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Significant Accounting Policies [Line Items]
Revenues	$ 511,352	$ 435,565	$ 393,422
Post-trade Services [Member]
Significant Accounting Policies [Line Items]
Revenues	15,763	15,346	11,090
Post-trade Services [Member] | Transferred over Time [Member]
Significant Accounting Policies [Line Items]
Revenues	15,669	15,013	9,657
Post-trade Services [Member] | Transferred at a Point in Time [Member]
Significant Accounting Policies [Line Items]
Revenues	$ 94	$ 333	$ 1,433

Significant Accounting Polici_8

Significant Accounting Policies - Summary of Revenue Recognized from Contract Liabilities and Remaining Balance (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Significant Accounting Policies [Line Items]
Deferred revenues, beginning balance	$ 2,810
Payments received in advance of services to be performed	21,056
Revenue recognized for services performed during the period	(20,396)
Foreign Currency Translation	29
Deferred revenues, ending balance	3,499
Information Services [Member]
Significant Accounting Policies [Line Items]
Deferred revenues, beginning balance	1,959
Payments received in advance of services to be performed	7,439
Revenue recognized for services performed during the period	(7,260)
Deferred revenues, ending balance	2,138
Post-trade Services [Member]
Significant Accounting Policies [Line Items]
Deferred revenues, beginning balance	851
Payments received in advance of services to be performed	13,617
Revenue recognized for services performed during the period	(13,136)
Foreign Currency Translation	29
Deferred revenues, ending balance	$ 1,361

Significant Accounting Polici_9

Significant Accounting Policies - Additional Information (Detail 1) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01 $ in Millions	Dec. 31, 2019USD ($)
Significant Accounting Policies [Line Items]
Aggregate amount of transaction price allocated to remaining performance obligations	$ 41.7
Expected time to recognize revenue for remaining performance obligation	31 months

Net Capital Requirements - Addi

Net Capital Requirements - Additional Information (Detail) $ in Millions	Dec. 31, 2019USD ($)
Brokers And Dealers [Abstract]
Aggregate net capital and financial resources in excess of required level	$ 219.7
Aggregate net capital and financial resources, minimum capital requirement	$ 15.8

Fair Value Measurements - Valua

Fair Value Measurements - Valuation of Company's Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Money market funds	$ 99,755	$ 112,529
Trading securities	92,642	93,139
Foreign currency forward position	(2,772)	(1,021)
Assets Fair Value Total	327,460	351,613
Corporate Debt [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available-for-sale	137,835	146,966
Trading securities	31,120	71,861
U.S. Treasuries [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Trading securities	55,305	17,178
Mutual Funds Held In Rabbi Trust [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Trading securities	6,217	4,100
Foreign Currency Forward Position [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Foreign currency forward position	(2,772)	(1,021)
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Money market funds	99,755	112,529
Assets Fair Value Total	99,755	112,529
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets Fair Value Total	227,705	239,084
Level 2 [Member] | Corporate Debt [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available-for-sale	137,835	146,966
Trading securities	31,120	71,861
Level 2 [Member] | U.S. Treasuries [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Trading securities	55,305	17,178
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	6,217	4,100
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	$ (2,772)	$ (1,021)

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Hedge derivative expiration period	1 month
Proceeds from the sales and maturities of securities available-for-sale	$ 262.1	$ 409.3	$ 219.2
Net unrealized gains on trading securities	$ 0.8

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Foreign Currency Forward Contracts (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Derivatives Fair Value [Line Items]
Fair value of the (liability)	$ (2,772)	$ (1,021)
Foreign Currency Forward Position [Member]
Derivatives Fair Value [Line Items]
Notional value	155,885	106,306
Fair value of notional	158,657	107,327
Fair value of the (liability)	$ (2,772)	$ (1,021)

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Company's Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Available For Sale Securities [Line Items]
Trading securities, Amortized cost	$ 91,031	$ 93,574
Trading securities, Gross unrealized gains	1,625	233
Trading securities, Gross unrealized losses	(14)	(668)
Trading securities, Estimated fair value	92,642	93,139
Investments, Amortized cost	228,150	241,130
Investments, Gross unrealized gains	2,346	260
Investments, Gross unrealized losses	(19)	(1,285)
Investments, Estimated fair value	230,477	240,105
Corporate Debt [Member]
Schedule Of Available For Sale Securities [Line Items]
Securities available-for-sale, Amortized cost	137,119	147,556
Securities available-for-sale, Gross unrealized gains	721	27
Securities available-for-sale, Gross unrealized losses	(5)	(617)
Securities available-for-sale, Estimated fair value	137,835	146,966
Trading securities, Amortized cost	31,120	72,274
Trading securities, Gross unrealized gains	14	8
Trading securities, Gross unrealized losses	(14)	(421)
Trading securities, Estimated fair value	31,120	71,861
U.S. Treasuries [Member]
Schedule Of Available For Sale Securities [Line Items]
Trading securities, Amortized cost	54,738	16,953
Trading securities, Gross unrealized gains	567	225
Trading securities, Estimated fair value	55,305	17,178
Mutual Funds Held In Rabbi Trust [Member]
Schedule Of Available For Sale Securities [Line Items]
Trading securities, Amortized cost	5,173	4,347
Trading securities, Gross unrealized gains	1,044
Trading securities, Gross unrealized losses		(247)
Trading securities, Estimated fair value	$ 6,217	$ 4,100

Fair Value Measurements - Sum_3

Fair Value Measurements - Summary of Fair Value of Investments Based upon Contractual Maturities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Less than one year	$ 120,850	$ 134,255
Due in 1 - 5 years	109,627	105,850
Total	$ 230,477	$ 240,105

Fair Value Measurements - Fair

Fair Value Measurements - Fair Values and Unrealized Losses on Corporate Debt Investments (Detail) - Corporate Debt [Member] - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Available For Sale Securities [Line Items]
Less than Twelve Months, Estimated fair value	$ 27,999	$ 80,282
Less than Twelve Months, Gross unrealized losses	(18)	(256)
Twelve Months or More, Estimated fair value	4,406	87,028
Twelve Months or More, Gross unrealized losses	(1)	(782)
Estimated fair value, Total	32,405	167,310
Gross unrealized losses, Total	$ (19)	$ (1,038)

Acquisition - Additional Inform

Acquisition - Additional Information (Detail) - LiquidityEdge LLC [Member] $ in Thousands	Nov. 01, 2019USD ($)shares
Business Acquisition [Line Items]
Aggregate consideration	$ 152,677
Cash consideration	$ 103,900
Business combination, shares of common stock | shares	146,450
Business combination, common stock value	$ 48,800
Business combination, period for shares of common stock placed in escrow	18 months
Business combination, shares of common stock received period	6 months
Escrow [Member]
Business Acquisition [Line Items]
Business combination, shares of common stock | shares	43,937

Acquisition - Summary of Prelim

Acquisition - Summary of Preliminary Purchase Price Allocation (Detail) - USD ($) $ in Thousands	Nov. 01, 2019	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill		$ 146,861	$ 59,713
LiquidityEdge LLC [Member]
Business Acquisition [Line Items]
Purchase price	$ 152,677
Less: acquired cash	(2,935)
Purchase price, net of acquired cash	149,742
Accounts receivable	(1,811)
Intangible assets	(58,780)
Prepaid expenses and other assets	(4,168)
Accounts payable, accrued expenses and other liabilities	2,165
Goodwill	$ 87,148

Acquisition - Summary of Acquir

Acquisition - Summary of Acquired Intangible Assets (Detail) - LiquidityEdge LLC [Member] $ in Thousands	Nov. 01, 2019USD ($)
Acquired Finite Lived Intangible Assets [Line Items]
Costs	$ 58,780
Customer Relationships [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Costs	$ 58,690
Useful Lives	15 years
Tradename - Finite Life [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Costs	$ 90
Useful Lives	1 year

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Summary of Changes in Goodwill and Intangible Assets With Indefinite Lives (Details) - Indefinite-lived Intangible Assets [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Goodwill [Line Items]
Balance at beginning of period	$ 59,713
Balance at end of period	146,861
LiquidityEdge LLC [Member]
Goodwill [Line Items]
Goodwill from acquisition	$ 87,148

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Summary of Company's Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Cost	$ 70,972	$ 12,154
Accumulated amortization	(9,986)	(9,192)
Net carrying amount	60,986	2,962
Technology [Member]
Finite Lived Intangible Assets [Line Items]
Cost	5,770	5,770
Accumulated amortization	(5,770)	(5,770)
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Cost	64,332	5,634
Accumulated amortization	(3,451)	(2,672)
Net carrying amount	60,881	2,962
Non-Competition Agreements [Member]
Finite Lived Intangible Assets [Line Items]
Cost	380	380
Accumulated amortization	(380)	(380)
Tradenames and Patents [Member]
Finite Lived Intangible Assets [Line Items]
Cost	490	370
Accumulated amortization	(385)	$ (370)
Net carrying amount	$ 105

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense associated with identifiable intangible assets	$ 0.8	$ 0.4	$ 0.4
Estimated total amortization expense 2020	3.3
Estimated total amortization expense 2021	5.7
Estimated total amortization expense 2022	6.9
Estimated total amortization expense 2023	7.9
Estimated total amortization expense 2024	$ 6.7

Capitalized Software, Furnitu_3

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, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	$ 206,981	$ 183,639
Accumulated depreciation and amortization	(135,186)	(120,629)
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	71,795	63,010
Software Development Costs [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	119,911	97,113
Computer Hardware and Related Software [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	48,379	42,705
Office Hardware [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	5,725	5,909
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	5,000	5,385
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Furniture, equipment, leasehold improvements and capitalized software, Gross	$ 27,966	$ 32,527

Capitalized Software, Furnitu_4

Capitalized Software, Furniture, Equipment and Leasehold Improvements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Abstract]
Software development costs	$ 22.4	$ 11.7

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 28,928	$ 31,617	$ 36,045
State and local	7,686	5,928	3,848
Foreign	13,234	8,862	7,234
Total current provision	49,848	46,407	47,127
Deferred:
Federal	2,579	(1,416)	6,171
State and local	403	(272)	661
Foreign	(308)	515	(280)
Total deferred provision	2,674	(1,173)	6,552
Provision for income taxes	$ 52,522	$ 45,234	$ 53,679

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Pre Tax Income [Line Items]
Pre-tax income from U.S. operations	$ 190,400	$ 168,500	$ 165,200
U.S. federal tax at statutory rate	21.00%	21.00%	35.00%
Provisional tax charge recorded due to enactment of Tax Act	$ 11,700
Re-measurement of U.S. deferred tax assets	6,700
Repatriation taxes on accumulated undistributed foreign earnings	5,000
Reduction in provisional tax charge		$ 400
Unrecognized tax benefits	6,831	4,718	$ 2,650	$ 29
Recognized penalties and interest on unrecognized tax benefits	600	400	200
Penalties and interest accrued on unrecognized tax benefits	$ 1,200	600
New York State [Member] | Earliest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2010
New York State [Member] | Latest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2017
Foreign Country [Member]
Schedule Of Pre Tax Income [Line Items]
Pre-tax income from foreign operations	$ 67,000	$ 49,600	$ 36,600

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, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
U.S. federal tax at statutory rate	21.00%	21.00%	35.00%
State and local taxes - net of federal benefit	2.50%	2.00%	1.50%
Credits and deductions related to research activities	(0.30%)	(0.30%)	(1.20%)
Foreign rate differential benefit	(0.50%)	(0.50%)	(2.90%)
Excess tax benefit from stock-based compensation	(3.50%)	(2.10%)	(11.60%)
Tax Cuts and Jobs Act provisional tax charge		(0.20%)	5.80%
Other, net	1.20%	0.80%
Provision for income taxes	20.40%	20.70%	26.60%

Income Taxes - Summary of Compa

Income Taxes - Summary of Company's Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Stock compensation expense	$ 4,926	$ 4,967
Operating lease liabilities	20,227
Other	892	3,569
Total deferred tax assets	26,045	8,536
Valuation allowance			$ (4,648)	$ (7,235)
Net deferred tax assets	26,045	8,536
Deferred tax liabilities:
Depreciation and amortization	(4,085)	(1,847)
Capitalized software development costs	(5,306)	(3,776)
Goodwill and intangible assets	(1,120)	(898)
Operating lease right-of-use assets	(16,515)
Deferred tax (liability), net	$ (981)
Deferred tax asset, net		$ 2,015

Income Taxes - Summary of Chang

Income Taxes - Summary of Changes in Valuation Allowance (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Valuation allowance at beginning of year	$ 4,648	$ 7,235
Expiration of capital loss carryforwards	$ (4,648)
Federal and state tax rate changes		(2,587)
Valuation allowance at end of year		$ 4,648

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 4,718	$ 2,650	$ 29
Additions attributable to state and local apportionment	2,113	2,068	2,650
Reductions for tax positions of prior years			(29)
Balance at end of year	$ 6,831	$ 4,718	$ 2,650

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended												12 Months Ended
	Jan. 31, 2019	Sep. 30, 2017	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Oct. 31, 2016	Jan. 31, 2016
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
Cash dividends declared per common share			$ 0.51	$ 0.51	$ 0.51	$ 0.51	$ 0.42	$ 0.42	$ 0.42	$ 0.42	$ 0.33	$ 0.33	$ 0.33	$ 0.33	$ 2.04	$ 1.68	$ 1.32
Share Repurchase Program [Member]
Class of Stock [Line Items]
Shares repurchase program period	2 years	15 months
Shares repurchase program authorized	$ 100,000,000	$ 100,000,000										$ 100,000,000							$ 25,000,000
Shares repurchase program additional authorized amount																		$ 50,000,000
Commencement date	2019-04	2017-10
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, 2019	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Outstanding shares of voting common stock at the beginning of year	37,639,917
Exercise of stock options	106,899	120,588	380,967
Outstanding shares of voting common stock at the end of year	37,935,984	37,639,917
Voting Common Stock [Member]
Class of Stock [Line Items]
Outstanding shares of voting common stock at the beginning of year	37,640,000	37,621,000	37,544,000
Exercise of stock options	107,000	121,000	262,000
Issuance of restricted stock, net of shares withheld for withholding tax payments and cancellations	103,000	22,000	39,000
Treasury shares used for acquisition	146,000
Repurchases	(60,000)	(124,000)	(224,000)
Outstanding shares of voting common stock at the end of year	37,936,000	37,640,000	37,621,000

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended				12 Months Ended
	Jan. 31, 2019	Nov. 30, 2018	Apr. 30, 2017	Jan. 31, 2016	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for grant under the stock incentive plans					93,946
Weighted-average fair value option granted					$ 58.37	$ 56.11	$ 40.08
Number of awards excluded from option-pricing model					2
Grant date fair value					$ 33,639
Fair value assumptions, Dividend yield rate					0.80%	0.80%	0.80%
Closing price of common stock					$ 379.11
Unrecognized compensation costs related to non-vested					$ 7,800
Weighted-average period over which cost is expected to be recognized					2 years 7 months 6 days
Pay-out ranges, Minimum					0.00%
Pay-out ranges, Maximum					150.00%
Incentive Stock Options [Member] | President and Chief Operating Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of stock option equity instruments granted during the period	76,868
Grant date fair value	$ 2,900
Share-based compensation arrangement by share-based payment award award vesting date	Jan. 22, 2024
Fair value assumptions, Risk free interest rate	2.60%
Fair value assumptions, Volatility rate	25.80%
Fair value assumptions, Dividend yield rate	0.80%
Share-based compensation arrangement by share-based payment award, options expiry date	Jul. 22, 2024
Incentive Stock Options [Member] | President and Chief Operating Officer [Member] | Range One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average fair value option granted	$ 272.88
Number of stock option equity instruments granted during the period	35,679
Percentage of fair market value of the common stock on the grant date	125.00%
Incentive Stock Options [Member] | President and Chief Operating Officer [Member] | Range Two [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average fair value option granted	$ 294.71
Number of stock option equity instruments granted during the period	41,189
Percentage of fair market value of the common stock on the grant date	135.00%
Incentive Stock Options [Member] | Chief Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of stock option equity instruments granted during the period		148,524
Grant date fair value		$ 5,500
Share-based compensation arrangement by share-based payment award award vesting date		Nov. 8, 2023
Fair value assumptions, Risk free interest rate		3.10%
Fair value assumptions, Volatility rate		25.90%
Fair value assumptions, Dividend yield rate		0.80%
Share-based compensation arrangement by share-based payment award, options expiry date		May 8, 2024
Incentive Stock Options [Member] | Chief Executive Officer [Member] | Range One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average fair value option granted		$ 257.78
Number of stock option equity instruments granted during the period		69,113
Percentage of fair market value of the common stock on the grant date		125.00%
Incentive Stock Options [Member] | Chief Executive Officer [Member] | Range Two [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average fair value option granted		$ 278.40
Number of stock option equity instruments granted during the period		79,411
Percentage of fair market value of the common stock on the grant date		135.00%
Restricted Stock and Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs related to non-vested					$ 31,000
Weighted-average period over which cost is expected to be recognized					1 year 7 months 6 days
Performance Based Share [Member] | Chief Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grant date fair value		$ 5,500
Share-based compensation arrangement by share-based payment award award vesting date		Nov. 8, 2023
Fair value assumptions, Risk free interest rate		3.10%
Fair value assumptions, Volatility rate		26.10%
Fair value assumptions, Dividend yield rate		0.80%
Number of non-option equity instruments granted during the period		37,742
Performance period		5 years
Performance Based Share [Member] | Chief Executive Officer [Member] | Range One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of non-option equity instruments granted during the period		17,942
Fair value per share on the grant date		$ 257.78
Percentage of fair market value of the common stock on the grant date		125.00%
Performance Based Share [Member] | Chief Executive Officer [Member] | Range Two [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of non-option equity instruments granted during the period		19,800
Fair value per share on the grant date		$ 278.40
Percentage of fair market value of the common stock on the grant date		135.00%
Performance Based Share [Member] | Chief Operating Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grant date fair value	$ 2,900
Share-based compensation arrangement by share-based payment award award vesting date	Jan. 22, 2024
Fair value assumptions, Risk free interest rate	2.60%
Fair value assumptions, Volatility rate	25.90%
Fair value assumptions, Dividend yield rate	0.80%
Number of non-option equity instruments granted during the period	18,914
Performance period	5 years
Performance Based Share [Member] | Chief Operating Officer [Member] | Range One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of non-option equity instruments granted during the period	8,969
Fair value per share on the grant date	$ 272.88
Percentage of fair market value of the common stock on the grant date	125.00%
Performance Based Share [Member] | Chief Operating Officer [Member] | Range Two [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of non-option equity instruments granted during the period	9,945
Fair value per share on the grant date	$ 294.71
Percentage of fair market value of the common stock on the grant date	135.00%
Performance Based Share [Member] | Officers and Senior Managers [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options Expiration Period			2 years	4 years
Pay-out ranges, Minimum			0.00%	0.00%
Pay-out ranges, Maximum			150.00%	150.00%
Number of non-option equity instruments granted during the period			9,367	33,509
Fair value per share on the grant date			$ 186.74	$ 103.30
Share-based compensation arrangement by share-based payment award, actual share payout percent			38.80%	106.50%
Share-based compensation arrangement by share-based payment award, actual share payout share			3,634	35,680
Performance Based Share [Member] | Officers and Senior Managers [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			Apr. 1, 2020	Jan. 31, 2020
Share-based compensation arrangement by share-based payment award, award vesting rights			50.00%	50.00%
Performance Based Share [Member] | Officers and Senior Managers [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 date			Apr. 1, 2021	Jan. 31, 2021
Share-based compensation arrangement by share-based payment award, award vesting rights			50.00%	50.00%
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					617	989	1,034
Percentage of shares grant to participants					20.00%
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 Plan_3

Stock-Based Compensation Plans - Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employees [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 24,214	$ 14,752	$ 13,448
Employees [Member] | Restricted Stock and Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	20,182	12,559	11,566
Employees [Member] | Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	4,032	2,193	1,882
Non-Employee Directors [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	25,294	15,850	14,421
Non-Employee Directors [Member] | Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 1,080	$ 1,098	$ 973

Stock-Based Compensation Plan_4

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, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected life (years)	5 years	5 years	5 years
Risk-free interest rate	2.60%	2.20%	1.90%
Expected volatility	25.90%	26.90%	28.00%
Expected dividend yield	0.80%	0.80%	0.80%

Stock-Based Compensation Plan_5

Stock-Based Compensation Plans - Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Beginning balance	575,564	529,611	855,740
Number of Shares, Granted	82,474	168,217	54,838
Number of Shares, Canceled	(548)	(1,676)
Number of Shares, Exercised	(106,899)	(120,588)	(380,967)
Number of Shares, Ending Balance	550,591	575,564	529,611
Number of Shares, Exercisable	171,782
Weighted Average Exercise Price, Beginning Balance	$ 132.93	$ 67.60	$ 36.80
Weighted Average Exercise Price, Granted	279.57	261.19	156.85
Weighted Average Exercise Price, Canceled	198.67	142.69
Weighted Average Exercise Price, Exercised	28.24	24.66	11.26
Weighted Average Exercise Price, Ending Balance	175.16	$ 132.93	$ 67.60
Weighted Average Exercise Price, Exercisable	$ 96.71
Remaining Contractual Term, Outstanding at December 31, 2019	2 years 9 months 18 days
Remaining Contractual Term, Exercisable at December 31, 2019	1 year 6 months
Intrinsic Value, Exercised	$ 33,639
Intrinsic Value, Ending Balance	112,294
Intrinsic Value, Exercisable	$ 48,512

Stock-Based Compensation Plan_6

Stock-Based Compensation Plans - Summary of Performance of Share Activity for Annual Awards (Detail) - Performance Shares [Member] - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Target share pay-out	16,716	10,479	12,971
Actual share pay-out (paid in following year)	19,400	10,479	8,094
Weighted average fair value per share on grant date	$ 223.81	$ 202.04	$ 155.53

Stock-Based Compensation Plan_7

Stock-Based Compensation Plans - Restricted Stock and Performance Share Activity (Detail) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Restricted Shares, Beginning balance	271,870	319,599	383,978
Number of Restricted Shares, Granted	118,632	59,179	61,434
Number of Restricted Shares, Performance share pay-out	87,163	8,094	21,422
Number of Restricted Shares, Canceled	(2,321)	(4,046)	(4,590)
Number of Restricted Shares, Vested	(129,312)	(110,956)	(142,645)
Number of Restricted Shares, Ending balance	346,032	271,870	319,599
Weighted Average Grant Date Fair Value, Beginning balance	$ 112.47	$ 88.77	$ 71.50
Weighted Average Grant Date Fair Value, Ending balance	$ 154.27	$ 112.47	$ 88.77

Earnings Per Share - Basic and

Earnings Per Share - Basic and Diluted Weighted Average Shares Outstanding Used to Compute Earnings Per Share (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share Basic And Diluted [Abstract]
Basic weighted average shares outstanding	37,083	36,958	36,864
Dilutive effect of stock options and restricted stock	873	897	1,174
Diluted weighted average shares outstanding	37,956	37,855	38,038

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
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	146,822	83,718	31,766

Credit Agreement - Additional I

Credit Agreement - Additional Information (Detail)	1 Months Ended				12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017Extension_Option	Oct. 31, 2015USD ($)	Dec. 31, 2019USD ($)
Line Of Credit Facility [Line Items]
Revolving loans and letters of credit				$ 100,000,000
Letter of credit outstanding					$ 1,000,000
Additional Credit Agreement				$ 50,000,000
Amount available under credit agreement					$ 99,000,000
Period of credit agreement				2 years
Equity interest					65.00%
Minimum [Member]
Line Of Credit Facility [Line Items]
Excess judgments against the company					$ 10,000,000
Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Expiration period of credit agreement	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Period of credit agreement			1 year
Number of additional option to extend maturity date | Extension_Option			2

Leases - Additional Information

Leases - Additional Information (Detail) $ in Thousands	1 Months Ended	12 Months Ended
	Sep. 30, 2019USD ($)ft²	Dec. 31, 2019USD ($)Agreement
Lessee Lease Description [Line Items]
Operating lease, option to extend		Certain leases contain options to extend the initial term at the Company’s discretion
Operating lease, existence of option to extend [true false]		true
Weighted average remaining lease term		13 years 3 months 18 days
Weighted average discount rate		5.90%
Area of square feet for office space | ft²	15,646
Lease commencement date	Dec. 1, 2019
Lease expiration date	Jan. 15, 2027
Aggregate minimum rental commitment amount	$ 8,300
Operating lease right-of-use assets		$ 81,399
Operating lease liabilities		$ 97,991
Number of lease agreements assigned to third parties | Agreement		2
Future lease obligation under sublease arrangements		$ 3,800
Property One [Member]
Lessee Lease Description [Line Items]
Lease termination dates		2020-11
Property Two [Member]
Lessee Lease Description [Line Items]
Lease termination dates		2022-02
Office Space [Member]
Lessee Lease Description [Line Items]
Operating lease right-of-use assets	7,000
Operating lease liabilities	$ 7,000
Minimum [Member]
Lessee Lease Description [Line Items]
Term of lease contract		1 year
Maximum [Member]
Lessee Lease Description [Line Items]
Term of lease contract		15 years

Leases - Schedule of Components

Leases - Schedule of Components of Occupancy Expense (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Lease Cost [Line Items]
Net lease cost	$ 11,044
Other, net [Member]
Lease Cost [Line Items]
Operating lease cost for subleased/assigned properties	2,422
Sublease income for subleased/assigned properties	(2,422)
Occupancy [Member]
Lease Cost [Line Items]
Operating lease cost	10,875
Variable lease costs	$ 169

Leases - Schedule of Maturity o

Leases - Schedule of Maturity of Lease Liabilities (Detail) $ in Thousands	Dec. 31, 2019USD ($)
Leases [Abstract]
2020	$ 10,955
2021	11,667
2022	10,379
2023	10,149
2024	10,816
2025 and thereafter	89,690
Total lease payments	143,656
Less: interest	45,665
Present value of lease liabilities	$ 97,991

Leases - Summary of Minimum Lea

Leases - Summary of Minimum Lease Commitments (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Operating Leases Future Minimum Payments Due [Abstract]
2019	$ 9,764
2020	10,919
2021	10,114
2022	9,067
2023	8,738
2024 and thereafter	95,467
Operating Leases	$ 144,069

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Settlement days of bond transaction	within one to two trading days
Collateral deposits	$ 4.1	$ 1.1

Segment and Geographic Inform_3

Segment and Geographic Information - Additional Information (Detail) - Segment	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
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 Inform_4

Segment and Geographic Information - Summary of Revenue and Long-lived Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 511,352	$ 435,565	$ 393,422
Long-lived assets	71,795	63,010
United States [Member]
Segment Reporting Information [Line Items]
Revenues	424,731	367,373	332,982
Long-lived assets	62,356	55,200
United Kingdom [Member]
Segment Reporting Information [Line Items]
Revenues	84,076	66,241	58,991
Long-lived assets	9,410	7,787
Other [Member]
Segment Reporting Information [Line Items]
Revenues	2,545	1,951	$ 1,449
Long-lived assets	$ 29	$ 23

Retirement and Deferred Compe_2

Retirement and Deferred Compensation Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Compensation And Retirement Disclosure [Abstract]
Contribution to defined plans	$ 3.3	$ 2.6	$ 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	$ 6.2	$ 4.1

Parent Company Information - Co

Parent Company Information - Condensed Statements of Financial Condition (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 270,124	$ 246,322
Investments, at fair value	230,477	240,105
Accounts receivable	62,017	57,535
Intangible assets, net of accumulated amortization	60,986	2,962
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	71,795	63,010
Operating lease right-of-use assets	81,399
Prepaid expenses and other assets	30,770	22,468
Deferred tax assets, net	501	3,424
Total assets	954,930	695,539
Liabilities
Accrued employee compensation	47,365	39,053
Income and other tax liabilities	16,690	16,432
Accounts payable, accrued expenses and other liabilities	19,294	29,366
Operating lease liabilities	97,991
Total liabilities	184,839	87,661
Stockholders' equity
Preferred stock
Common stock	122	122
Additional paid-in capital	342,541	341,860
Treasury stock	(153,388)	(184,962)
Retained earnings	591,086	463,252
Accumulated other comprehensive loss	(10,270)	(12,394)
Total stockholders' equity	770,091	607,878	$ 514,768	$ 468,013
Total liabilities and stockholders' equity	954,930	695,539
Series A Preferred Stock [Member]
Stockholders' equity
Preferred stock
MarketAxess Holdings Inc. (Parent) [Member]
ASSETS
Cash and cash equivalents	48,241	95,840
Investments, at fair value	141,318	149,266
Accounts receivable	63	59
Receivable from subsidiaries	5,997
Intangible assets, net of accumulated amortization	30
Furniture, equipment, leasehold improvements and capitalized software, net of accumulated depreciation and amortization	25,247	25,742
Operating lease right-of-use assets	68,559
Investments in subsidiaries	570,145	356,363
Prepaid expenses and other assets	3,506	4,439
Deferred tax assets, net	3,472	5,039
Income and other tax receivable	3,219
Total assets	869,797	636,748
Liabilities
Accrued employee compensation	6,543	5,667
Income and other tax liabilities		2,612
Payable to subsidiaries		3
Accounts payable, accrued expenses and other liabilities	9,254	20,588
Operating lease liabilities	83,909
Total liabilities	99,706	28,870
Stockholders' equity
Preferred stock
Common stock	122	122
Additional paid-in capital	342,541	341,860
Treasury stock	(153,388)	(184,962)
Retained earnings	591,086	463,252
Accumulated other comprehensive loss	(10,270)	(12,394)
Total stockholders' equity	770,091	607,878
Total liabilities and stockholders' equity	869,797	636,748
MarketAxess Holdings Inc. (Parent) [Member] | Series A Preferred Stock [Member]
Stockholders' equity
Preferred stock

Parent Company Information - _2

Parent Company Information - Condensed Statements of Operations and Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Expenses
Employee compensation and benefits	$ 131,079	$ 109,117	$ 102,313
Depreciation and amortization	26,857	23,080	19,274
Technology and communications	26,792	23,866	20,048
Professional and consulting fees	25,534	21,521	19,367
Occupancy	11,639	14,176	6,125
General and administrative	15,696	11,353	11,121
Total expenses	260,470	222,981	193,807
Operating income	250,882	212,584	199,615
Other income (expense)
Investment income	8,063	6,112	3,619
Other, net	(1,521)	(610)	(1,466)
Total other income	6,542	5,502	2,153
Provision for income taxes	52,522	45,234	53,679
Net income	204,902	172,852	148,089
Comprehensive income	207,026	170,684	150,091
MarketAxess Holdings Inc. (Parent) [Member]
Dividends from subsidiary	165,000	130,000	120,000
Expenses
Employee compensation and benefits	16,100	10,785	11,289
Depreciation and amortization	1,919	1,760	1,971
Technology and communications	13	43	41
Professional and consulting fees	6,523	4,932	4,185
Occupancy	850	7,381	143
General and administrative	2,252	1,513	852
Total expenses	27,657	26,414	18,481
Operating income	137,343	103,586	101,519
Other income (expense)
Investment income	5,305	3,835	2,608
Other, net	(1,344)	(711)	(685)
Total other income	3,961	3,124	1,923
Income before income taxes and equity in undistributed income of subsidiaries	141,304	106,710	103,442
Provision for income taxes	(9,442)	(7,350)	(13,935)
Income before equity in undistributed income of subsidiaries	150,746	114,060	117,377
Equity in undistributed income of subsidiaries	54,156	58,792	30,712
Net income	204,902	172,852	148,089
Other comprehensive income (loss), net	2,124	(2,168)	2,002
Comprehensive income	$ 207,026	$ 170,684	$ 150,091

Parent Company Information - _3

Parent Company Information - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities
Net income	$ 204,902	$ 172,852	$ 148,089
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	26,857	23,080	19,274
Amortization of operating lease right-of-use assets	5,795
Stock-based compensation expense	25,294	15,850	14,421
Deferred taxes	2,682	(1,258)	6,590
Other	(786)	2,338	1,953
Changes in operating assets and liabilities:
(Increase) in accounts receivable	(2,962)	(5,117)	(2,353)
(Increase) in prepaid expenses and other assets	(4,624)	(3,791)	(7,039)
Decrease (Increase) in trading securities	4,045	856	(17,081)
Increase in accrued employee compensation	8,312	2,551	1,719
Increase in income and other tax liabilities	187	2,965	5,770
(Decrease) increase in accounts payable, accrued expenses and other liabilities	(1,509)	14,374	(1,614)
Increase in operating lease liabilities	(829)
Net cash provided by operating activities	265,935	223,917	168,035
Cash flows from investing activities
Proceeds from maturities and sales, available-for-sale investments	170,936	333,791	187,794
Purchases, available-for-sale investments	(160,827)	(336,533)	(215,831)
Purchases of furniture, equipment and leasehold improvements	(12,292)	(35,888)	(12,086)
Net cash (used in) investing activities	(122,051)	(50,296)	(53,653)
Cash flows from financing activities
Cash dividend on common stock	(76,231)	(62,432)	(48,888)
Exercise of stock options	1,207	2,973	1,972
Withholding tax payments on restricted stock vesting and stock option exercises	(25,820)	(8,043)	(27,691)
Repurchases of common stock	(17,256)	(25,171)	(42,461)
Net cash (used in) financing activities	(118,100)	(92,673)	(117,068)
Effect of exchange rate changes on investments	1,011	(1,640)	1,457
Cash and cash equivalents including restricted cash
Net increase (decrease) for the period	26,795	79,308	(1,229)
Beginning of period	247,458	168,150	169,379
End of period	274,253	247,458	168,150
Supplemental cash flow information:
Cash paid during the year for income taxes	51,766	47,208	43,997
Non-cash investing and financing activity:
Treasury stock used for acquisition of business	(48,830)
Mutual Funds Held In Rabbi Trust [Member]
Changes in operating assets and liabilities:
Decrease (Increase) in trading securities	(2,118)	(933)	(1,839)
MarketAxess Holdings Inc. (Parent) [Member]
Cash flows from operating activities
Net income	204,902	172,852	148,089
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,919	1,760	1,971
Amortization of operating lease right-of-use assets	4,027
Stock-based compensation expense	21,800	14,257	13,071
Deferred taxes	1,255	(2,515)	5,004
Equity in undistributed income of subsidiaries	(54,156)	(58,792)	(30,712)
Other	328	710	1,581
Changes in operating assets and liabilities:
(Increase) in accounts receivable	(4)	(14)	205
(Increase) decrease in receivable from subsidiaries	(6,000)	7,529	17,518
(Increase) in prepaid expenses and other assets	933	(782)	687
Increase in accrued employee compensation	876	567	607
(Increase) in income and other tax receivable	(3,219)
Increase in income and other tax liabilities	(2,612)	469	(825)
(Decrease) increase in accounts payable, accrued expenses and other liabilities	(2,039)	13,619	(261)
Increase in operating lease liabilities	1,191
Net cash provided by operating activities	168,018	149,190	155,986
Cash flows from investing activities
Acquisition of business, net of cash and cash equivalents acquired	(102,320)
Repayment from subsidiary			5,000
Proceeds from maturities and sales, available-for-sale investments	170,936	333,791	187,794
Purchases, available-for-sale investments	(160,827)	(336,533)	(215,831)
Purchases of furniture, equipment and leasehold improvements	(1,424)	(24,786)	(2,160)
Purchase of intangible asset	(30)
Net cash (used in) investing activities	(93,665)	(27,528)	(25,197)
Cash flows from financing activities
Cash dividend on common stock	(76,231)	(62,432)	(48,888)
Exercise of stock options	1,207	2,973	1,972
Withholding tax payments on restricted stock vesting and stock option exercises	(25,820)	(8,043)	(27,691)
Repurchases of common stock	(17,256)	(25,171)	(42,461)
Net cash (used in) financing activities	(118,100)	(92,673)	(117,068)
Effect of exchange rate changes on investments	(3,852)	4,129	(4,687)
Cash and cash equivalents including restricted cash
Net increase (decrease) for the period	(47,599)	33,118	9,034
Beginning of period	95,840	62,722	53,688
End of period	48,241	95,840	62,722
Supplemental cash flow information:
Cash paid during the year for income taxes	41,025	37,721	37,769
Non-cash investing and financing activity:
Treasury stock used for acquisition of business	(48,830)
MarketAxess Holdings Inc. (Parent) [Member] | Mutual Funds Held In Rabbi Trust [Member]
Changes in operating assets and liabilities:
Decrease (Increase) in trading securities	$ (1,183)	$ (470)	$ (949)