Virtu Itg 10-K 1 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 20, 2018	Jun. 30, 2017
Document and Entity Information
Entity Registrant Name	INVESTMENT TECHNOLOGY GROUP, INC.
Entity Central Index Key	920,424
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 689,569,053
Entity Common Stock, Shares Outstanding		33,080,682
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash and cash equivalents	$ 287,452	$ 277,977
Cash restricted or segregated under regulations and other	18,599	40,353
Deposits with clearing organizations	57,388	62,556
Securities owned, at fair value	1,559	2,557
Receivables from brokers, dealers and clearing organizations	193,907	152,294
Receivables from customers	74,695	54,486
Premises and equipment, net	53,960	59,333
Capitalized software, net	41,259	38,606
Goodwill	11,054	10,102
Intangibles, net	14,040	15,390
Income taxes receivable	3,917	873
Deferred taxes assets	4,902	38,688
Other assets	22,124	22,070
Total assets	784,856	775,285
Liabilities:
Accounts payable and accrued expenses	166,495	174,343
Short-term bank loans	101,422	72,150
Payables to brokers, dealers and clearing organizations	119,278	100,188
Payables to customers	23,568	12,272
Securities sold, not yet purchased, at fair value	1	249
Income taxes payable	6,003	4,552
Deferred tax liabilities	1,750
Term debt	3,104	6,367
Total liabilities	421,621	370,121
Commitments and contingencies
Stockholders' Equity:
Preferred stock, $0.01 par value; 1,000,000 shares authorized; no shares issued or outstanding
Common stock, $0.01 par value; 100,000,000 shares authorized; 52,639,823 and 52,456,165 shares issued at December 31, 2017 and December 31, 2016, respectively	526	525
Additional paid-in capital	250,216	248,748
Retained earnings	486,957	536,350
Common stock held in treasury, at cost; 20,038,809 and 19,830,032 shares at December 31, 2017 and December 31, 2016, respectively	(353,067)	(346,482)
Accumulated other comprehensive loss (net of tax)	(21,397)	(33,977)
Total stockholders' equity	363,235	405,164
Total liabilities and stockholders' equity	$ 784,856	$ 775,285

Consolidated Statements of Fin3

Consolidated Statements of Financial Condition (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Consolidated Statements of Financial Condition
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	52,639,823	52,456,165
Common stock held in treasury, at cost; shares	20,038,809	19,830,032

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Commissions and fees	$ 399,691	$ 376,463	$ 405,679
Recurring	75,911	81,916	107,184
Other	8,092	10,673	121,940
Total revenues	483,694	469,052	634,803
Expenses:
Compensation and employee benefits	184,716	188,886	209,323
Transaction processing	100,747	90,271	91,492
Occupancy and equipment	68,563	56,189	57,495
Telecommunications and data processing services	48,477	56,643	51,523
Restructuring charges		9,620
Other general and administrative	72,641	108,466	101,915
Interest expense	2,025	2,217	1,829
Total expenses	477,169	512,292	513,577
Income (loss) before income tax expense (benefit)	6,525	(43,240)	121,226
Income tax expense (benefit)	45,965	(17,322)	29,656
Net (loss) income	$ (39,440)	$ (25,918)	$ 91,570
(Loss) income per share:
Basic (in dollars per share)	$ (1.19)	$ (0.79)	$ 2.70
Diluted (in dollars per share)	$ (1.19)	$ (0.79)	$ 2.63
Basic weighted average number of common shares outstanding (in shares)	33,009	32,906	33,907
Diluted weighted average number of common shares outstanding (in shares)	33,009	32,906	34,815

Statements of Comprehensive (Lo

Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statements of Comprehensive (Loss) Income
Net (loss) income	$ (39,440)	$ (25,918)	$ 91,570
Other comprehensive income (loss), net of tax:
Currency translation adjustment	12,580	(14,482)	(13,601)
Other comprehensive income (loss)	12,580	(14,482)	(13,601)
Comprehensive (loss) income	$ (26,860)	$ (40,400)	$ 77,969

Statements of Changes in Stockh

Statements of Changes in Stockholders’ Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Retained Earnings	Common Stock Held in Treasury	Accumulated Other Comprehensive Income/(Loss)	Total
Balance at Dec. 31, 2014	$ 522	$ 240,135	$ 487,462	$ (306,629)	$ (5,894)	$ 415,596
Increase (Decrease) in Stockholders' Equity
Net (loss) income			91,570			91,570
Other comprehensive (loss) income					(13,601)	(13,601)
Issuance of common stock in connection with employee stock option exercises and for restricted stock unit awards		(20,299)		20,621		322
Issuance of common stock for the employee stock purchase plan	1	1,166				1,167
Shares withheld for net settlements of share-based awards				(8,978)		(8,978)
Purchase of common stock for treasury				(42,046)		(42,046)
Dividend declared on common stock		2	(7,406)	109		(7,295)
Share-based compensation		18,086				18,086
Balance at Dec. 31, 2015	523	239,090	571,626	(336,923)	(19,495)	454,821
Increase (Decrease) in Stockholders' Equity
Net (loss) income			(25,918)			(25,918)
Other comprehensive (loss) income					(14,482)	(14,482)
Issuance of common stock in connection with employee stock option exercises and for restricted stock unit awards	1	(16,600)		19,237		2,638
Issuance of common stock for the employee stock purchase plan	1	1,320				1,321
Shares withheld for net settlements of share-based awards				(6,795)		(6,795)
Purchase of common stock for treasury				(22,112)		(22,112)
Dividend declared on common stock		4	(9,358)	111		(9,243)
Share-based compensation		24,934				24,934
Balance at Dec. 31, 2016	525	248,748	536,350	(346,482)	(33,977)	405,164
Increase (Decrease) in Stockholders' Equity
Net (loss) income			(39,440)			(39,440)
Other comprehensive (loss) income					12,580	12,580
Issuance of common stock in connection with employee stock option exercises and for restricted stock unit awards	1	(20,749)		21,026		278
Issuance of common stock for the employee stock purchase plan		1,098				1,098
Shares withheld for net settlements of share-based awards				(10,779)		(10,779)
Purchase of common stock for treasury				(16,933)		(16,933)
Dividend declared on common stock		15	(9,310)	101		(9,194)
Share-based compensation		20,238				20,238
Cumulative effect of accounting change		866	(643)			223
Balance at Dec. 31, 2017	$ 526	$ 250,216	$ 486,957	$ (353,067)	$ (21,397)	$ 363,235

Statements of Changes in Stock7

Statements of Changes in Stockholders’ Equity (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statements of Changes in Stockholders’ Equity
Issuance of common stock in connection with employee stock option exercises, shares		24,498	39,002
Issuance of common stock in connection with restricted stock unit awards, shares	1,311,239	1,133,183	1,159,047
Net excess tax benefit		$ 0.2	$ 2.1
Issuance of common stock for the employee stock purchase plan, shares	74,551	95,981	70,924
Shares withheld for net settlements of share-based awards, shares	531,346	391,195	418,135
Purchase of common stock for treasury, shares	885,285	1,336,132	1,992,831

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities:
Net (loss) income	$ (39,440)	$ (25,918)	$ 91,570
Adjustments to reconcile net (loss) income to net cash used in operating activities:
Gain on sale of investment research operations		(21)	(107,699)
Depreciation and amortization	45,153	43,523	44,151
Deferred income tax expense (benefit)	33,826	(15,755)	12,912
Provision for doubtful accounts	375	67	496
Non-cash share-based compensation	20,238	25,620	16,667
Leasehold asset write-off	7,492
Other intangible asset impairment	325
Changes in operating assets and liabilities:
Cash restricted or segregated under regulations and other	22,334	(3,048)	55
Deposits with clearing organizations	8,661	1,420	(1,113)
Securities owned, at fair value	1,004	3,048	5,973
Receivables from brokers, dealers and clearing organizations	(26,701)	871,317	(404,818)
Receivables from customers	(11,832)	(11,738)	53,909
Accounts payable and accrued expenses	(11,292)	13,034	(18,978)
Payables to brokers, dealers and clearing organizations	7,658	(853,923)	366,462
Payables to customers	7,907	2,681	(775)
Securities sold, not yet purchased, at fair value	(247)	(2,397)	(5,102)
Income taxes receivable/payable	2,892	(11,889)	1,710
Excess tax benefit from share-based payment arrangements		(880)	(2,982)
Other, net	(339)	(59)	(3,692)
Net cash provided by operating activities	68,014	35,082	48,746
Cash Flows from Investing Activities:
Proceeds from sale of investment research operations, net of deal costs		6,125	111,240
Capital purchases	(19,402)	(21,315)	(11,905)
Capitalization of software development costs	(27,782)	(24,617)	(26,003)
Net cash (used in) provided by investing activities	(47,184)	(39,807)	73,332
Cash Flows from Financing Activities:
Repayments of long term debt	(3,963)	(6,200)	(8,820)
Proceeds from (repayments of) borrowing under short-term bank loans	29,272	(9,784)	3,573
Debt issuance costs	(762)	(810)
Excess tax benefit from share-based payment arrangements		880	2,982
Common stock issued	1,376	3,743	1,742
Common stock repurchased	(16,933)	(22,112)	(42,046)
Dividends paid	(9,156)	(9,124)	(7,030)
Shares withheld for net settlements of share-based awards	(10,779)	(6,795)	(8,978)
Net cash used in financing activities	(10,945)	(50,202)	(58,577)
Effect of exchange rate changes on cash and cash equivalents	(410)	2,251	(8,058)
Net increase (decrease) in cash and cash equivalents	9,475	(52,676)	55,443
Cash and cash equivalents - beginning of period	277,977	330,653	275,210
Cash and cash equivalents - end of period	287,452	277,977	330,653
Supplemental cash flow information:
Interest paid	4,960	6,116	3,607
Income taxes paid	10,515	$ 9,880	15,098
Supplemental disclosure of non-cash investing and financing activities:
Capital expenditures funded by financing from seller	$ 400		$ 3,606

Organization and Basis of Prese

Organization and Basis of Presentation	12 Months Ended
	Dec. 31, 2017
Organization and Basis of Presentation
Organization and Basis of Presentation	(1) Organization and Basis of Presentation Investment Technology Group, Inc. (the “Company” or “ITG”) was formed as a Delaware corporation on July 22, 1983. Its principal subsidiaries include: (1) ITG Inc., AlterNet Securities, Inc. (“AlterNet”) and ITG Derivatives LLC (through February 16, 2018) (“ITG Derivatives”), institutional broker-dealers in the United States (“U.S.”), (2) ITG Canada Corp., an institutional broker-dealer in Canada, (3) Investment Technology Group Limited, an institutional broker-dealer in Europe, (4) ITG Australia Limited, an institutional broker-dealer in Australia, (5) ITG Hong Kong Limited, an institutional broker-dealer in Hong Kong, (6) ITG Software Solutions, Inc., the Company’s intangible property, software development and maintenance subsidiary in the U.S., and (7) ITG Solutions Network, Inc., a holding company for ITG Analytics, Inc., a provider of pre- and post-trade analysis, fair value and trade optimization services, and ITG Platforms Inc., a provider of workflow technology solutions and network connectivity services for the financial community. ITG is a global financial technology company that helps leading brokers and asset managers improve returns for investors around the world. ITG empowers traders to reduce the end-to-end cost of implementing investments via liquidity, execution, analytics and workflow technology solutions. ITG has offices in Asia Pacific, Europe and North America and offers execution services in more than 50 countries. The Company’s business is organized into four reportable operating segments: U.S. Operations, Canadian Operations, European Operations and Asia Pacific Operations (see Note 22, Segment Reporting ). The four operating segments offer a wide range of solutions for asset managers and broker‑dealers in the areas of execution services, workflow technology and analytics. These offerings include trade execution services and solutions for portfolio management, as well as pre‑trade analytics and post‑trade analytics and processing. Regional segment results exclude the impact of Corporate activity, which is presented separately and includes investment income from treasury activity, certain non-operating revenues and other gains as well as costs not associated with operating the businesses within the Company’s regional segments. These costs include, among others, (a) the costs of being a public company, such as certain staff costs, a portion of external audit fees, and reporting, filing and listing costs, (b) intangible asset amortization, (c) interest expense, (d) professional fees associated with the Company's global transfer pricing structure, (e) foreign exchange gains or losses and (f) certain non-operating expenses. The consolidated financial statements and accompanying notes are prepared in accordance with accounting principles generally accepted in the U.S. (“U.S. GAAP”). All material intercompany balances and transactions have been eliminated in consolidation. The consolidated financial statements reflect all adjustments which, in the opinion of management, are necessary for the fair presentation of the financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	(2) Summary of Significant Accounting Policies Principles of Consolidation The consolidated financial statements represent the consolidation of the accounts of ITG and its subsidiaries in conformity with U.S. GAAP. All intercompany accounts and transactions have been eliminated in consolidation. Investments in unconsolidated companies (generally 20 to 50 percent ownership), in which the Company has the ability to exercise significant influence but neither has a controlling interest nor is the primary beneficiary, are accounted for under the equity method. Investments in entities in which the Company does not have the ability to exercise significant influence are accounted for under the cost method. Under certain criteria indicated in Accounting Standards Codification (“ASC”) 810, Consolidation , a partially‑owned affiliate would be consolidated as a variable interest entity when it has less than a 50% ownership if the Company was the primary beneficiary of that entity. At the present time, there are no interests in variable interest entities. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets, liabilities, revenues and expenses. Actual results could differ from those estimates. Revenue Recognition Transactions in securities, commissions and fees and related expenses are recorded on a trade date basis. Commissions and fees are derived primarily from (1) commissions charged for trade execution services, (2) income generated from net executions, whereby equity orders are filled at different prices within or at the National Best Bid and Offer and (3) commission sharing arrangements. Recurring revenues are derived from the following primary sources: (1) connectivity fees, (2) software and analytical products and services and (3) maintenance and customer technical support for the Company’s order management system. Prior to the Company’s divestitures of its investment research operations in May 2016 and December 2015, recurring revenues included subscriptions for these services. Substantially all of the Company’s recurring revenue arrangements do not require significant modification or customization of the underlying software. Accordingly, the vast majority of software revenue is recognized pursuant to the requirements of ASC 985, Software . Specifically, revenue recognition from subscriptions, maintenance, customer technical support and professional services commences when all of the following criteria are met: (1) persuasive evidence of a legally binding arrangement with a customer exists, (2) delivery has occurred, (3) the fee is deemed fixed or determinable and free of contingencies or significant uncertainties and (4) collection is probable. Where software is provided under a hosting arrangement, revenue is accounted for as a service arrangement since the customer does not have the contractual right to take possession of the software at any time during the hosting period without significant penalty (or it is not feasible for the customer to run the software on either its own hardware or third party hardware). Subscription agreements for software products generally include provisions that, among other things, allow customers to receive unspecified future software upgrades for no additional fee, as well as the right to use the software products with maintenance for the term of the agreement, typically one to three years. Under these agreements, once all four of the above noted revenue recognition criteria are met, revenue is recognized ratably over the term of the subscription agreement. If a subscription agreement includes an acceptance provision, revenue is not recognized until the earlier of the receipt of written acceptance from the customer or, if not notified by the customer to cancel the license agreement, the expiration of the acceptance period. Revenues for analytical products sold on a subscription basis are recognized when services are rendered provided that persuasive evidence of a legally binding arrangement exists, the fees are fixed or determinable and collectability is reasonably assured. Other revenues include: (1) the net spread on foreign exchange transactions executed on a principal basis to facilitate equity trades by clients in different currencies, as well as on other foreign exchange transactions unrelated to equity trading, (2) non-recurring consulting services, such as one-time implementation and customer training related activities (3) investment income from treasury activity, (4) interest income on securities borrowed in connection with customers’ settlement activities, (5) market gains/losses resulting from temporary positions in securities assumed in the normal course of agency trading (including trade errors and client trade accommodations), (6) non-recurring gains and losses such as divestitures, (7) fees earned for clearing securities transactions on behalf of other broker-dealers, (8) income from principal trading in Canada, including within the Company’s closed arbitrage trading desk (for historical periods up until April 2016) and (9) the net interest spread earned on securities borrowed and loaned transactions within the Company’s closed U.S. matched-book securities lending operations (for historical periods up until June 2016). Revenues from professional services, which are sold as a multiple‑element arrangement with the implementation of software, are deferred until go‑live (or acceptance, if applicable) of the software and recognized in the same manner as the subscription over the remaining term of the initial contract. Professional services that are not connected with the implementation of software are recognized on a time and material basis as incurred. Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less to be cash equivalents. Fair Value of Financial Instruments All of the Company’s financial instruments are carried at fair value or amounts approximating fair value. Cash and cash equivalents, securities owned and securities sold, not yet purchased and certain payables are carried at market value or fair value. Securities Transactions Receivables from brokers, dealers and clearing organizations include amounts receivable for fails to deliver, cash deposits for securities borrowed, the net amounts receivable on open transactions from clearing organizations and non-U.S. broker-dealers and billed amounts for commissions and fees and balance transfers on client commission arrangements, net of an allowance for doubtful accounts. Payables to brokers, dealers and clearing organizations include amounts payable for fails to receive, securities loaned and execution cost payables. Receivables from customers consist of fails to deliver, the net amounts receivable on open transactions from non-U.S. customers, as well as billed amounts for commissions and fees, net of an allowance for doubtful accounts. Payables to customers primarily consist of fails to receive. Commissions and fees and related expenses for all securities transactions are recorded on a trade date basis. Securities owned, at fair value consist of common stock and mutual funds. Securities sold, not yet purchased, at fair value consist of common stock. Marketable securities owned are valued using market quotes from third parties. Unrealized gains and losses are included in other revenues in the Consolidated Statements of Operations. Securities Borrowed and Loaned Securities borrowed and securities loaned transactions are reported as collateralized financings. Securities borrowed transactions require the Company to deposit cash, letters of credit, or other collateral with the lender. With respect to securities loaned, the Company receives collateral in the form of cash or other collateral in amounts generally in excess of the fair value of securities loaned. The Company monitors the fair value of securities borrowed and loaned on a daily basis, with additional collateral obtained or refunded as necessary. Securities borrowed and securities loaned transactions are recorded at the amount of cash collateral advanced or received, adjusted for additional collateral advanced or received. The Company currently engages in securities borrowed and securities loaned transactions solely as part of its clearing process primarily to facilitate customer transactions, including for shortened or extended settlement activities and for failed settlements. On these transactions, interest income for securities borrowed is recorded in other revenue while interest expense from securities loaned is recorded in transaction processing expense on the Consolidated Statements of Operations. Client Commission Arrangements Institutional customers are permitted to allocate a portion of their gross commissions to pay for research products and other services provided by third parties and the Company’s subsidiaries. The amounts allocated for those purposes are commonly referred to as client commission arrangements. The cost of independent research and directed brokerage arrangements is accounted for on an accrual basis. Commission revenue is recorded when earned on a trade date basis. Payments relating to client commission arrangements are netted against the commission revenues. Research receivable, including prepaid research on behalf of customers and balance transfers due from other broker‑dealers, net of an allowance is included in receivables from customers and receivables from brokers, dealers and clearing organizations, while accrued research payable is included in accounts payable and accrued expenses in the Consolidated Statements of Financial Condition. Client commissions allocated for research and related research receivable and accrued research payable balances for the years ended December 31, 2017, 2016 and 2015 were as follows (dollars in millions): 2017 2016 2015 Client commissions allocated for research $ 96.3 $ 100.7 $ 110.9 Research receivable, gross $ 5.3 $ 3.0 $ 3.5 Allowance for research receivable (0.1) (0.1) (0.1) Research receivable, net of allowance $ 5.2 $ 2.9 $ 3.4 Accrued research payable $ 51.3 $ 45.8 $ 46.3 Capitalized Software Software development costs are capitalized when the technological feasibility of a product has been established. Technological feasibility is established when all planning, designing, coding and testing activities have been devised to ensure that the product can be produced to meet its design specifications, including functions, features, and technical performance requirements. All costs incurred to establish technological feasibility are expensed as incurred. Capitalized software costs are amortized using the straight‑line method over a three‑year period beginning when the product is available for general release to customers. Research and Development All research and development costs are expensed as incurred. Research and development costs, which are primarily included in other general and administrative expenses and compensation and employee benefits in the Consolidated Statements of Operations, were approximately $32.8 million, $31.8 million and $29.2 million, excluding routine maintenance, for the years ended December 31, 2017, 2016 and 2015, respectively. Business Combinations, Goodwill and Other Intangibles Assets acquired and liabilities assumed are recorded at their fair values on the date of acquisition. The cost to be allocated in a business combination includes consideration paid to the sellers, including cash and the fair values of assets distributed and the fair values of liabilities assumed. Both direct (e.g., legal and professional fees) and indirect costs of the business combination are expensed as incurred. Certain agreements to acquire entities include potential additional consideration that is payable, contingent on the acquired company maintaining or achieving specified earnings levels in future periods. The fair value of any contingent consideration is recognized on the acquisition date with subsequent changes in that fair value reflected in the results of operations. The consolidated financial statements and results of operations reflect an acquired business from the date of acquisition. An intangible asset is recognized as an asset apart from goodwill if it arises from contractual or other legal rights or if it is separable (i.e., capable of being separated or divided from the acquired entity and sold, transferred, licensed, rented, or exchanged). Goodwill represents the excess of the cost of each acquired entity over the amounts assigned to the tangible and identifiable intangible assets acquired and liabilities assumed. The judgments that are made in determining the estimated fair value assigned to each class of assets acquired and liabilities assumed, as well as asset lives, can materially impact net income in periods following a business combination. Traditional approaches used to determine fair value include the income, cost and market approaches. The income approach presumes that the value of an asset can be estimated by the net economic benefit to be received over the life of the asset, discounted to present value. The cost approach presumes that an investor would pay no more for an asset than its replacement or reproduction cost. The market approach estimates value based on what other participants in the market have paid for reasonably similar assets. Although each valuation approach is considered in valuing the assets acquired, the approach or combination of approaches ultimately selected is based on the characteristics of the asset and the availability of information. Any goodwill is assessed no less than annually for impairment. The guidance for goodwill impairment testing allows an entity to assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount or to proceed directly to performing the two-step impairment test. The fair values used in the Company’s two-step impairment testing are determined by the discounted cash flow method (an income approach) and where appropriate, a combination of the discounted cash flow method and the guideline company method (a market approach). An impairment loss is indicated if the estimated fair value of a reporting unit is less than its net book value. In such a case, the impairment loss is calculated as the amount by which the carrying value of goodwill exceeds its implied fair value. In determining the fair value of each of the Company’s reporting units, the discounted cash flow analyses employed require significant assumptions and estimates about the future operations of each reporting unit. Significant judgments inherent in these analyses include the determination of appropriate discount rates, the amount and timing of expected future cash flows and growth rates. The cash flows employed in the Company’s discounted cash flow analyses are based on financial budgets and forecasts developed internally by management. The Company’s discount rate assumptions are based on a determination of its required rate of return on equity capital. Other intangibles with definite lives are amortized over their useful lives. All other intangibles are assessed at least annually for impairment. If impairment is indicated, an impairment loss is calculated as the amount by which the carrying value of an intangible asset exceeds its estimated fair value. Premises and Equipment Furniture, fixtures and equipment are carried at cost and are depreciated using the straight‑line method over the estimated useful lives of the assets (generally three to seven years). Leasehold improvements are carried at cost and are amortized using the straight‑line method over the lesser of the estimated useful lives of the related assets or the non‑cancelable lease term. Impairment of Long‑Lived Assets Long‑lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Determination of recoverability is generally based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition, as well as specific appraisal in certain instances. Measurement of an impairment loss for long‑lived assets that management expects to hold and use is based on the fair value of the asset as estimated using a cash flow model. Long‑lived assets to be disposed of are reported at the lower of carrying amount or fair value less costs to sell. Contingencies and Uncertainties The Company may be subject to losses that arise from litigation, mediation, arbitration, regulatory proceedings and various contingencies and uncertainties. Liabilities are recognized when a loss is probable and can be reasonably estimated. Income Taxes Income taxes are accounted for using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. 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 recorded against deferred tax assets if it is more likely than not that such assets will not be realized. An uncertain tax position is recognized based on the determination of whether or not a tax position is more likely than not to be sustained upon examination based upon the technical merits of the position. If this recognition threshold is met, the tax benefit is then measured based on the largest benefit that has a greater than fifty percent likelihood of being realized upon ultimate resolution. Taxes Collected from Customers and Remitted to Governmental Authorities Taxes assessed by a governmental authority that are directly imposed on a revenue producing transaction between the Company and its customers, including but not limited to sales, use, value added and some excise taxes are presented in the consolidated financial statements on a net basis (excluded from revenues). Earnings per Share Basic earnings per share is determined by dividing earnings by the average number of shares of common stock outstanding, while diluted earnings per share is determined by dividing earnings by the average number of shares of common stock adjusted for the dilutive effect of common stock equivalents by application of the treasury stock method. Common stock equivalents are excluded from the diluted calculation if their effect is anti-dilutive. Share‑based Compensation Share‑based compensation expense requires measurement of compensation cost for share‑based awards at fair value and recognition of compensation cost over the vesting period. For awards with graded vesting schedules that only have service conditions, the Company recognizes compensation cost evenly over the requisite service period for the entire award using the straight‑line attribution method. For awards with service conditions as well as performance or market conditions, the Company recognizes compensation cost on a straight‑line basis over the requisite service period for each separately vesting portion of the award as if the award was, in‑substance, multiple awards. The fair value of stock options granted is estimated using the Black‑Scholes option‑pricing model, which considers, among other factors, the expected term of the award and the expected volatility of the Company’s stock price. Although the Black‑Scholes model meets the requirements of ASC 718, Compensation—Stock Compensation , the fair values generated by the model may not be indicative of the actual fair values of the underlying awards, as it does not consider other factors important to those share‑based compensation awards, such as continued employment, periodic vesting requirements and limited transferability. The risk-free interest rate used in the Black-Scholes option-pricing model is based on the U.S. Treasury yield curve in effect at the time of grant. The expected option life is based on historical experience of employee exercise behavior. Expected volatility is based on historical volatility, implied volatility, price observations taken at regular intervals and other factors deemed appropriate. Expected dividend is based upon the current dividend rate. The fair value of restricted stock unit awards is based on the fair value of the Company’s common stock on the grant date. Certain restricted stock unit awards granted have both service and market conditions. Awards with market conditions are valued based on (a) the grant date fair value of the award for equity-based awards or (b) the period-end fair value for liability-based awards. Grant date fair value for market condition based awards is determined using a Monte Carlo simulation model to simulate a range of possible future stock prices for the Company’s common stock. Compensation costs for awards with market conditions are recognized for each separately vesting portion of the award over the estimated service period calculated by the Monte Carlo simulation model. For restricted stock unit awards with a performance condition, fair value is estimated throughout the life of the award based on the probability of achieving the performance condition. Excess tax benefits (which represent the excess of actual tax benefits received at the date of vesting or settlement over the benefits recognized over the vesting period or upon issuance of share-based payments) and tax deficiencies (which represent the amount by which actual tax benefits received at the date of vesting or settlement is lower than the benefits recognized over the vesting period or upon issuance of share-based payments) are recorded in the income statement as an increase or decrease in income taxes when the awards vest or are settled. Cash flows related to income tax deductions, if any, in excess of the compensation cost recognized on share‑based awards exercised or vested during the period presented (excess tax benefit) were classified in financing cash flows in the Consolidated Statements of Cash Flows through December 31, 2016. As of January 1, 2017, due to the adoption of Accounting Standards Update (“ASU”) 2016-09, Improvements to Employee Share-Based Payment Accounting , excess tax benefits, along with other income tax cash flows, are recorded as an operating activity in the statement of cash flows rather than, as previously required, a financing activity. For more information on the impact of this standard to the consolidated financial statements, see “ Recently Adopted Accounting Standards” below. Phantom stock awards are settled in cash and are therefore classified as liability awards. The fair value of the liability is remeasured at each reporting date until final settlement using the fair value of the Company’s common stock on that date. At December 31, 2017, the Company did not have any phantom awards outstanding, as the Company discontinued granting phantom share awards effective January 1, 2015 and the last awards outstanding vested on February 22, 2016. Foreign Currency Translation Assets and liabilities denominated in non-U.S. currencies are translated at rates of exchange prevailing on the date of the Consolidated Statements of Financial Condition, and revenues and expenses are translated at average rates of exchange during the fiscal year. Gains or losses on translation of the financial statements of a foreign operation, where the functional currency is other than the U.S. Dollar, together with the after-tax effect of exchange rate changes on intercompany transactions of a long-term investment nature, are reflected as a component of accumulated other comprehensive income in stockholders’ equity. Gains or losses on foreign currency transactions are included in other general and administrative expenses in the Consolidated Statements of Operations. Common Stock Held in Treasury, at Cost The purchase of treasury stock is accounted for under the cost method with the shares of stock repurchased reflected as a reduction to stockholders’ equity and included in common stock held in treasury, at cost, in the Consolidated Statements of Financial Condition. When treasury shares are reissued, they are recorded at the average cost of the treasury shares acquired. The Company held 20.0 million and 19.8 million shares of common stock in treasury as of December 31, 2017 and 2016, respectively. Recently Adopted Accounting Standards In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update 2014‑09, Revenue from Contracts with Customers . This standard created ASC 606, providing companies with a single five step revenue recognition model for use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry‑specific revenue guidance. The core principle of the model is to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. It also requires significant additional qualitative and quantitative disclosures describing the nature, amount, timing, and uncertainty of revenues and cash flows arising from contracts with customers, along with detailed information regarding the nature of the Company’s performance obligations and contracts and the timing of recognition and payment, among other items. ASC 606 is effective for annual and interim reporting periods beginning after December 15, 2017. On January 1, 2018, the Company adopted ASC 606, using the modified retrospective transition method applied to all contracts as of January 1, 2018. The Company has identified two key accounting changes that will affect the timing of revenue recognition upon adoption relating to bundled commission arrangements and fees for licenses of functional intellectual property. The financial impact of these accounting changes includes (1) a deferral of revenues primarily generated in the first half of the year for commissions attributable to analytics products under bundled arrangements that will be recognized over the course of the year as the performance obligations for those analytics products are satisfied and (2) an acceleration of license fee revenues to the delivery date for software provided for a specified period. These changes only relate to the timing of when revenue is recognized and have no effect on the underlying transaction price of the products and services the Company performs. Upon adoption, the Company recorded a net cumulative-effect decrease to opening retained earnings of approximately $ 0.04 million as of January 1, 2018, which is primarily related to: (i) the deferral of commissions allocated to analytics products in bundled commission arrangements where the analytics services have not yet been transferred to the customer as of December 31, 2017 but whose commissions were appropriately recognized in the previous year under the superseded revenue recognition guidance, and (ii) the acceleration of revenue for certain product license fees associated with the licenses of functional intellectual property recognized at the point in time the customer is able to use and benefit from the license instead of being appropriately recognized over the license period under the superseded revenue recognition guidance. In May 2017, the FASB issued ASU 2017-09, Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting . The amendments in this ASU clarify which changes to the terms or conditions of a share-based payment award must be accounted for as modifications. The new guidance allows entities to make non-substantive changes to awards without accounting for them as modifications, which results in fewer changes to the terms of an award being accounted for as modifications and reduces diversity in practice when applying modification accounting. ASU 2017-09 is effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods. This new guidance was adopted on January 1, 2018 and did not have a material effect on the Company’s financial statements. In November 2016, the FASB issued ASU 2016‑18, Statement of Cash Flows (Topic 230): Restricted Cash. The amendments in this ASU require that the statement of cash flows explain the change during the period in the total of cash, cash equivalents and restricted cash. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016‑18 is effective for annual reporting periods beginning after December 15, 2017, including interim periods within those fiscal years, with early adoption permitted. This new guidance was adopted on January 1, 2018 and did not have a material effect on the Company’s financial statements. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments . The amendments in this ASU provide specific guidance for eight specific cash flow classification issues, with the objective of reducing the existing diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows under Topic 230, Statement of Cash Flows . These amendments are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years, with early adoption permitted. This new guidance was adopted on January 1, 2018 and had no impact on the Company’s financial statements. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, which changes the accounting for certain aspects of share-based payments to employees. The new guidance requires, among its other provisions, that excess tax benefits (which represent the excess of actual tax benefits received at the date of vesting or settlement over the benefits recognized over the vesting period or upon issuance of share-based payments) and tax deficiencies (which represent the amount by which actual tax benefits received at the date of vesting or settlement is lower than the benefits recognized over the vesting period or upon issuance of share-based payments) be recorded in the statement of operations as an increase or decrease in income tax expense (benefit) when the awards vest or are settled. This is in contrast to the prior requirement that these excess tax benefits be recognized in additional paid-in capital and these tax deficiencies be recognized either as an offset to accumulated excess tax benefits, if any, or in the statement of operations. The new guidance also requires excess tax benefits to be classified along with other income tax cash flows as an operating activity in the statement of cash flows rather than, as previously required, a financing activity. The new guidance is effective for annual and interim reporting periods beginning after December 15, 2016 and as such was implemented on January 1, 2017. As a result of this adoption, the Company: · Recognized net excess tax benefits of $1.3 million during the year ended December 31, 2017, which is included in income tax benefit in the Consolidated Statements of Operations. · Elected to adopt the cash flow presentation of the excess tax benefits prospectively during the year ended December 31, 2017, where these benefits are classified along with other income tax cash flows as an operating activity in the Consolidated Statements of Cash Flows. · Elected to account for forfeitures as they occur rather than under the previous method of estimating the number of stock-based awards expected to vest in order to determine the amount of compensation cost to be recognized in each period. This resulted in an adjustment for the cumulative effect of this accounting change as of January 1, 2017

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Measurements
Fair Value Measurements	(3) Fair Value Measurements Fair value is 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. In determining fair value, various methods are used including market, income and cost approaches. Based on these approaches, certain assumptions that market participants would use in pricing the asset or liability are used, including assumptions about risk and/or the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market‑corroborated, or generally unobservable firm inputs. Valuation techniques that are used maximize the use of observable inputs and minimize the use of unobservable inputs. Based on the observability of the inputs used in the valuation techniques, fair value measured financial instruments are categorized according to the fair value hierarchy prescribed by ASC 820, Fair Value Measurements and Disclosures . The fair value hierarchy ranks the quality and reliability of the information used to determine fair values. Financial assets and liabilities carried at fair value are classified and disclosed in one of the following three categories: * Level 1: Fair value measurements using unadjusted quoted market prices in active markets for identical, unrestricted assets or liabilities. * Level 2: Fair value measurements using correlation with (directly or indirectly) observable market‑based inputs, unobservable inputs that are corroborated by market data, or quoted prices in markets that are not active. * Level 3: Fair value measurements using inputs that are significant and not readily observable in the market. Level 1 consists of financial instruments whose value is based on quoted market prices such as exchange‑traded mutual funds and listed equities. Level 2 includes financial instruments that are valued based upon observable market‑based inputs. Level 3 is comprised of financial instruments whose fair value is estimated based on internally developed models or methodologies utilizing significant inputs that are generally less readily observable. Fair value measurements for those items measured on a recurring basis are as follows (dollars in thousands): December 31, 2017 Total Level 1 Level 2 Level 3 Assets Securities owned, at fair value: Corporate stocks - trading securities $ 78 $ 78 $ — $ — Mutual funds 1,481 1,481 — — Total $ 1,559 $ 1,559 $ — $ — Liabilities Securities sold, not yet purchased, at fair value: Corporate stocks - trading securities 1 1 — — Total $ 1 $ 1 $ — $ — December 31, 2016 Total Level 1 Level 2 Level 3 Assets Securities owned, at fair value: Corporate stocks - trading securities $ 244 $ 244 $ — $ — Mutual funds 2,313 2,313 — — Total $ 2,557 $ 2,557 $ — $ — Liabilities Securities sold, not yet purchased, at fair value: Corporate stocks - trading securities 249 249 — — Total $ 249 $ 249 $ — $ — Cash and cash equivalents other than bank deposits are measured at fair value and primarily include money market mutual funds. Securities owned, at fair value and securities sold, not yet purchased, at fair value include corporate stocks, equity index mutual funds and bond mutual funds, all of which are exchange traded. Certain of the Company’s assets and liabilities are carried at contracted amounts that approximate fair value. Assets and liabilities that are recorded at contracted amounts approximating fair value consist primarily of receivables from and payables to brokers, dealers, clearing organizations and customers. These receivables and payables to brokers, dealers, clearing organizations and customers are short-term in nature and, following December 31, 2017, substantially all have settled at the contracted amounts. The Company believes the carrying amounts of its term-debt obligations at December 31, 2017 and 2016 approximate fair value because the interest rates on these instruments change with, or approximate, market interest rates.

Divestitures and Acquisitions

Divestitures and Acquisitions	12 Months Ended
	Dec. 31, 2017
Divestitures and Acquisitions
Divestitures and Acquisitions	(4) Divestitures and Acquisitions Formation of Derivatives Venture In September 2017, the Company signed a definitive agreement with Option Technology Solutions LLC (“OpTech”) to form Matrix Holdings Group (“Matrix”), a newly established derivatives execution and technology business focused on sell-side clients, professional traders and select hedge funds. The transaction closed and the venture launched in February 2018 following the receipt of required regulatory approvals and satisfaction of other customary closing conditions (see Note 24, Subsequent Events ). At closing, the Company contributed the ITG Derivatives entity, including its broker-dealer license and professional trader client base with revenues of $5.3 million during the year ended December 31, 2017, along with certain derivatives-focused software and technology for an initial minority stake of approximately 20%. OpTech contributed the management team, a retail-focused trading and analytics platform and capital. During the year ended December 31, 2017, the Company deemed the remaining value of a customer intangible asset recorded in ITG Derivatives of $0.3 million fully impaired and incurred legal fees related to the establishment of the Matrix derivatives venture of $0.8 million. The Company determined that the contribution of ITG Derivatives did not meet the requirements to be treated as a discontinued operation. As such, the results of ITG Derivatives through the closing date of the venture will be included in continued operations on the Consolidated Statements of Operations in the U.S. Operations segment. ITG Investment Research, LLC On May 27, 2016, the Company completed the sale of ITG Investment Research, LLC (“Investment Research”), a wholly owned subsidiary of the Company, to a wholly owned subsidiary of Leucadia National Corporation for $12 million in cash consideration. Upon completion of the sale, the Company recorded a pre-tax gain of approximately $21,000 and an after-tax gain of approximately $50,000. The pre-tax gain is recorded in other revenue on the Consolidated Statements of Operations as of December 31, 2016. The pre-tax gain is net of direct costs to sell Investment Research, including professional fees, cash compensation and the acceleration of previously issued restricted stock unit awards. The following table summarizes the components of the pre-tax gain (dollars in thousands): Cash proceeds from sale $ 12,000 Carrying value of net assets disposed (7,502) Direct selling costs (4,477) Pre-tax gain on sale $ 21 As a result of this divestiture, the Company reduced the headcount within its U.S. single stock sales trading operation. For more information, see Note 5, Restructuring Charges . The Company determined that the sale of Investment Research did not meet the requirements to be treated as a discontinued operation. As such, the results of Investment Research through the sale completion date of May 27, 2016 are included in continued operations on the Consolidated Statements of Operations, primarily in the U.S. Operations segment. Energy Research Operations On December 22, 2015, the Company completed the sale of the subsidiaries conducting its energy research operations to an affiliate of Warburg Pincus (“Buyer”), pursuant to an agreement dated November 5, 2015. Upon closing of the sale, the Buyer paid the Company $120.5 million in cash consideration. As part of this transaction, the Company agreed to distribute energy research to its institutional clients, serving as the exclusive sales partner for institutional investors for at least two years. Per an amendment, this distribution agreement was terminated as of December 31, 2016. The Company recorded a pre-tax gain upon completion of the sale of $107.7 million and an after-tax gain of $91.4 million. The pre-tax gain is recorded in other revenue on the Consolidated Statements of Operations for the year ended December 31, 2015. The pre-tax gain is net of a working capital adjustment on the closing balance sheet and direct costs to sell the energy research business, including professional fees, cash compensation, the acceleration of previously-issued deferred stock awards and $0.2 million of currency translation losses reclassified to the results of operations. The following table summarizes the components of the pre-tax gain (dollars in thousands): Cash proceeds from sale $ 120,500 Working capital adjustment (1,615) Carrying value of net assets disposed (3,025) Direct selling costs (8,161) Pre-tax gain on sale $ 107,699 The Company determined that the sale of the energy research operations did not meet the requirements to be treated as a discontinued operation. As such, the results of the energy research operations through the sale date of December 22, 2015 are included in continued operations on the Consolidated Statements of Operations, primarily in the U.S. Operations segment.

Restructuring Charges

Restructuring Charges	12 Months Ended
	Dec. 31, 2017
Restructuring Charges.
Restructuring Charges	(5) Restructuring Charges 2016 Restructuring As part of an end-to-end review of its business, the Company determined that its strategy is to increasingly focus its resources on its core capabilities in liquidity, execution, analytics and workflow technology solutions. To that end, in 2016, the Company implemented restructuring plans that (i) reduced headcount in its single stock sales trading and sales organizations, (ii) closed its U.S. matched-book securities lending operations and its Canadian arbitrage trading desk and (iii) identified additional annual cost savings from management delayering and the elimination of certain positions. Activity and liability balances recorded as part of the restructuring plan through December 31, 2017 are as follows (dollars in thousands): Amount Balance at December 31, 2016 $ 3,157 Utilized—cash (primarily severance related) (3,119) Accrual adjustment (58) Currency translation 26 Balance at December 31, 2017 $ 6 The payment of the remaining accrued costs is expected to continue through the first quarter of 2018.

Goodwill and Other Intangibles

Goodwill and Other Intangibles	12 Months Ended
	Dec. 31, 2017
Goodwill and Other Intangibles
Goodwill and Other Intangibles	(6) Goodwill and Other Intangibles Goodwill The following table presents the changes in the carrying amount of goodwill held entirely within the Company’s European Operations segment for the year ended December 31, 2017 (dollars in thousands): Total Balance at December 31, 2015 $ 11,933 Currency translation adjustment (1,831) Balance at December 31, 2016 $ 10,102 Currency translation adjustment 952 Balance at December 31, 2017 $ 11,054 Other Intangible Assets Acquired other intangible assets consisted of the following at December 31, 2017 and 2016 (dollars in thousands): December 31, 2017 December 31, 2016 Gross Carrying Accumulated Gross Carrying Accumulated Useful Lives Amount Amortization Amount Amortization (Years) Trade name $ 8,529 $ — $ 8,518 $ — — Customer-related intangibles 10,217 6,219 10,358 5,584 16.9 Proprietary software 23,321 22,197 23,165 21,456 8.4 Trading rights 339 — 339 — — Other 50 — 50 — — Total $ 42,456 $ 28,416 $ 42,430 $ 27,040 At December 31, 2017, indefinite‑lived intangibles not subject to amortization amounted to $8.9 million, of which $8.4 million related to the POSIT trade name. Amortization expense for definite‑lived intangibles was $1.3 million, $1.9 million and $3.2 million for the years ended December 31, 2017, 2016 and 2015, respectively. These amounts are included in other general and administrative expense in the Consolidated Statements of Operations. During the third quarter of 2017, the Company deemed the remaining value of a customer intangible asset recorded in ITG Derivatives of $0.3 million fully impaired. During the year ended December 31, 2016, no intangibles were deemed impaired, and accordingly, no adjustment was required. In May 2016, the Company disposed of $6.7 million of customer-related intangibles, net of accumulated amortization as a result of the sale of Investment Research (see Note 4, Divestitures and Acquisitions ). The Company’s estimate of future amortization expense for acquired other intangibles that exist at December 31, 2017 and 2016 is as follows (dollars in thousands): Estimated Year Amortization 2018 $ 1,017 2019 865 2020 653 2021 571 2022 571 Thereafter 1,447 Total $ 5,124 The following table represents the changes in the carrying amount of net intangible assets for the years ended December 31, 2017 and 2016 (dollars in thousands): Total Balance at December 31, 2015 $ 24,611 Amortization (1,852) Divestiture of energy research operations (6,684) Currency translation adjustment (685) Balance at December 31, 2016 $ 15,390 Amortization (1,276) Impairment charge (325) Currency translation adjustment 251 Balance at December 31, 2017 $ 14,040

Cash Restricted or Segregated U

Cash Restricted or Segregated Under Regulations and Other	12 Months Ended
	Dec. 31, 2017
Cash Restricted or Segregated Under Regulations and Other
Cash Restricted or Segregated Under Regulations and Other	(7) Cash Restricted or Segregated Under Regulations and Other Cash restricted or segregated under regulations and other represents (i) a special reserve bank account for the exclusive benefit of customers (“Special Reserve Bank Account”) maintained by ITG Inc. in accordance with Rule 15c3-3 of the Securities Exchange Act of 1934, as amended (“Customer Protection Rule”), or agreements for proprietary accounts of broker dealers (“PABs”), (ii) funds on deposit for Canadian and European trade clearing and settlement activity, (iii) segregated balances under a collateral account control agreement for the benefit of certain customers, and (iv) funds relating to the securitization of bank guarantees supporting the Company’s Australian and French leases.

Securities Owned and Sold, Not

Securities Owned and Sold, Not Yet Purchased	12 Months Ended
	Dec. 31, 2017
Securities Owned and Sold, Not Yet Purchased
Securities Owned and Sold, Not Yet Purchased	(8) Securities Owned and Sold, Not Yet Purchased The following is a summary of securities owned and securities sold, not yet purchased (dollars in thousands): Securities Sold, Not Yet Securities Owned Purchased December 31, December 31, December 31, December 31, 2017 2016 2017 2016 Corporate stocks - trading securities $ 78 $ 244 $ 1 $ 249 Mutual funds 1,481 2,313 — — Total $ 1,559 $ 2,557 $ 1 $ 249 Trading securities owned and sold, not yet purchased primarily consists of temporary positions obtained in the normal course of agency trading activities, including positions held in connection with the creation and redemption of exchange‑traded funds on behalf of clients.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Taxes
Income Taxes	(9) Income Taxes Income tax expense (benefit) consisted of the following components (dollars in thousands): 2017 2016 2015 Current: Federal $ (423) $ (9,918) $ 5,731 State 1,072 (624) (1,645) Foreign 11,490 8,975 12,647 12,139 (1,567) 16,733 Deferred: Federal 25,797 (12,687) 13,665 State 7,694 (2,217) 2,570 Foreign 335 (851) (3,312) 33,826 (15,755) 12,923 Total $ 45,965 $ (17,322) $ 29,656 Income (loss) before income taxes consisted of the following (dollars in thousands): 2017 2016 2015 U.S. $ (56,465) $ (81,579) $ 51,797 Foreign 62,990 38,339 69,429 Total $ 6,525 $ (43,240) $ 121,226 The components of the Company’s net deferred tax asset are as follows (dollars in thousands): 2017 2016 Deferred tax assets: Compensation and benefits $ 5,912 $ 9,715 Net operating loss and capital loss carryover 18,974 19,755 Share-based compensation 5,092 6,824 Research and development credits 7,438 7,550 Foreign tax credits 11,117 12,660 Tax benefits on uncertain tax positions 831 1,351 Goodwill and other intangibles 6,363 8,015 Depreciation 3,527 1,167 Capitalized software 383 — Rent 3,013 3,695 Other 700 1,564 Total deferred tax assets 63,350 72,296 Less: valuation allowance (58,448) (20,979) Total deferred tax assets, net of valuation allowance 4,902 51,317 Deferred tax liabilities: Capitalized software — (12,174) Indefinite life intangible (1,695) — Other (55) (455) Total deferred tax liabilities (1,750) (12,629) Net deferred tax assets $ 3,152 $ 38,688 Under ASC 740, Income Taxes , the Company regularly assesses the need for a valuation allowance against its deferred taxes. In making that assessment, both positive and negative evidence is considered related to the likelihood of realization of the deferred tax assets to determine, based on the weight of available evidence, whether it is more-likely than not that some or all of its deferred tax assets will not be realized. In evaluating the need for a valuation allowance, the Company considered its cumulative pre-tax loss in the U.S. jurisdiction over the previous three years as a significant piece of negative evidence. Prevailing accounting guidance limits the ability to consider other subjective evidence to support deferred tax assets, such as projections of future profits, when objective verifiable evidence such as a cumulative loss exists. As a result, the Company recorded a full valuation allowance against its U.S. deferred tax assets in the third quarter 2017, resulting in a non-cash charge of $48.1 million, which included $42.3 million related to deferred tax assets that existed at June 30, 2017. The Tax Cuts and Jobs Act of 2017 (the “Tax Cuts and Jobs Act”) was enacted on December 22, 2017, and introduced significant changes to U.S, income tax law. Effective in 2018, the Tax Cuts and Jobs Act reduces the U.S. statutory corporate tax rate from 35% to 21% and creates new taxes on certain foreign-sourced earnings and certain related party payments, which are referred to as the global intangible low-taxed income tax (“GILTI”) and the base erosion tax, respectively. In addition, under the Tax Cuts and Jobs Act, in 2017 the Company was subject to the mandatory inclusion in U.S. taxable income of all accumulated foreign subsidiary earnings not previously subject to U.S. tax. The mandatory inclusion did not result in any incremental U.S. tax expense in 2017 due to the impact of a U.S. tax loss in the current year and the utilization of foreign tax credits. Due to the timing of the enactment and the complexity involved in applying the provisions of the Tax Cuts and Jobs Act, the Company has made reasonable estimates of the effects and recorded provisional amounts in the 2017 consolidated financial statements. As the Company collects and prepares necessary data and interprets the Tax Cuts and Jobs Act and any additional guidance issued by the U.S. Treasury Department, the IRS, and other standard-setting bodies, additional adjustments to the provisional amounts may be made. Information needed to adjust provisional amounts include the completion of all international 2017 tax returns. These additional adjustments may materially impact the provision for income taxes and effective tax rate in the period in which the adjustments are made. We expect the final accounting for the tax effects of the Tax Cuts and Jobs Act to be completed in 2018. At December 31, 2017, the valuation allowance on U.S. deferred taxes was reduced to $37.7 million primarily from the realization of deferred tax assets following a tax method change and the reduction to gross deferred tax assets to incorporate the impact of the lower U.S. corporate tax rate under the Tax Cuts and Jobs Act. The remaining valuation allowance at December 31, 2017 relates to certain U.S. state credits and losses and a full valuation allowance on deferred tax assets held in the Asia Pacific entities, including loss carryforwards. The $4.9 million balance for deferred tax assets, net of the valuation allowance, at December 31, 2017 relates to temporary differences between financial statement carrying amounts and their respective tax bases in Europe and Canada. The Company has foreign tax credit carryforwards of $11.1 million that begin to expire in 2024 and research and development tax credits of $7.4 million that begin to expire in 2032. Net operating loss carryforwards expire as follows (dollars in thousands): Amount Years remaining Hong Kong and Australia $ 76,375 Indefinite State and local (United States) 36,111 13 - 20 years $ 112,486 The effective tax rate varied from the U.S. federal statutory income tax rate due to the following: 2017 2016 2015 U.S. federal statutory income tax rate 35.0 % 35.0 % 35.0 % State and local income taxes, net of U.S. federal income tax effect 0.6 5.2 0.4 Foreign tax impact, net (81.8) 6.2 (7.2) Deemed dividend on changes to internal capital structure outside North America (1) — — 5.4 Valuation allowance 585.8 — — Tax impact of Tax Cuts and Jobs Act 149.2 — — Stock windfall/shortfall (13.5) — — Impact of deductible basis on the sale of energy research business — — (14.8) Reserves released upon tax settlement — 18.6 — Non-deductible costs (2) 21.3 (22.8) 6.1 Other, net 7.9 (2.1) (0.4) Effective income tax rate 704.5 % 40.1 % 24.5 % (1) Reflects the impact of the tax on a deemed dividend from changes to the internal capital structure of the Company's operations outside of North America. (2) Includes the impact of the non-deductible payments in 2015 and charges accrued in 2016 payable to the Securities and Exchange Commission (the “SEC”) (see Note 21, Commitments and Contingencies ). Additionally, 2017 and 2016 includes non-deductible officer’s compensation. Under U.S. GAAP, the Company is allowed to make an accounting policy choice of either (1) treating taxes due on future U.S. inclusions in taxable income related to GILTI as a current-period expense when incurred (the “period cost method”) or (2) factoring such amounts into the Company’s measurement of its deferred taxes (the “deferred method”). The Company’s selection of an accounting policy with respect to the new GILTI tax rules will depend, in part, on its ongoing evaluation of its global income to determine whether it expects to have future U.S. inclusions in taxable income related to GILTI and, if so, what the impact is expected to be . Tax Uncertainties Under ASC 740, Income Taxes , a tax benefit from an uncertain tax position may be recognized only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities. The tax benefits recognized in the financial statements from such a position are measured based on the largest benefit that has a greater than fifty percent likelihood of being realized upon ultimate resolution. A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows (dollars in thousands): Uncertain Tax Benefits 2017 2016 2015 Balance, January 1 $ 7,356 $ 15,553 $ 14,395 Additions based on tax positions related to the current year 591 66 2,807 Additions based on tax positions of prior years 4 406 349 Reductions for tax positions of prior years (13) — (36) Reductions due to settlements with taxing authorities (64) (2,153) (1,773) Reductions due to expiration of statute of limitations (181) (6,516) (189) Balance, December 31 $ 7,693 $ 7,356 $ 15,553 The unrecognized tax benefits were $7.7 million and $7.4 million, respectively, at December 31, 2017 and 2016. At December 31, 2017, $4.5 million of the unrecognized tax benefits was netted against fully reserved U.S. deferred tax assets. With limited exception, the Company is no longer subject to U.S. federal, state, local or foreign income tax audits by taxing authorities for years preceding 2011. The Internal Revenue Service is currently examining the Company’s U.S. federal income tax returns for 2011 through 2012. Certain foreign state and local returns are also currently under various stages of audit for the tax years 2013 through 2014. The Company does not anticipate a significant change to the total of unrecognized tax benefits within the next twelve months. At December 31, 2017, interest expense of $2.1 million was accrued related to unrecognized tax benefits. As a continuing policy, interest accrued related to unrecognized tax benefits is recorded as income tax expense. During 2017, the Company recognized net reductions of $0.1 million of tax-related interest expense. During 2016 and 2015, the Company recognized a net reduction of $2.5 million and a net addition of $0.1 million, respectively, of tax-related interest expense. Tax penalties of $0.1 million were recorded during 2017. No penalties were recorded in 2016 or 2015.

Receivables and Payables

Receivables and Payables	12 Months Ended
	Dec. 31, 2017
Receivables and Payables
Receivables and Payables	(10) Receivables and Payables Receivables from, and Payables to, Brokers, Dealers and Clearing Organizations The following is a summary of receivables from, and payables to, brokers, dealers and clearing organizations at December 31 (dollars in thousands): Receivables from Payables to December 31, December 31, December 31, December 31, 2017 2016 2017 2016 Broker-dealers $ 189,817 $ 147,116 $ 105,022 $ 56,894 Clearing organizations 708 5,117 10,011 8,096 Securities borrowed 4,246 374 — — Securities loaned — — 4,245 35,198 Allowance for doubtful accounts (864) (313) — — Total $ 193,907 $ 152,294 $ 119,278 $ 100,188 Receivables from, and Payables to, Customers The following is a summary of receivables from, and payables to, customers at December 31 (dollars in thousands): Receivables from Payables to December 31, December 31, December 31, December 31, 2017 2016 2017 2016 Customers $ 75,062 $ 55,006 $ 23,568 $ 12,272 Allowance for doubtful accounts (367) (520) — — Net $ 74,695 $ 54,486 $ 23,568 $ 12,272 Allowance for Doubtful Accounts The Company maintains an allowance for doubtful accounts based upon an estimate of the amount of potential credit losses in existing accounts receivable, as determined from a review of past due balances, historical collection experience and other specific account data. Account balances are written off against the allowance when it is determined that the receivable is uncollectible. The allowance was increased by $0.4 million in 2017 and $0.1 million in 2016. Securities Borrowed and Loaned In 2016, the Company closed its U.S. matched-book securities lending operations. At December 31, 2017, the only remaining balances for securities borrowed and securities loaned related to customer settlement activities. The gross amounts of interest earned on cash provided to counterparties as collateral for securities borrowed, and interest incurred on cash received from counterparties as collateral for securities loaned within the U.S. matched-book operations prior to the wind-down of all balances, and the resulting net amount included in other revenue on the Consolidated Statements of Operations for 2016 and 2015 were as follows (dollars in thousands): 2016 2015 Interest earned $ 1,961 $ 5,512 Interest incurred (1,132) (3,720) Net $ 829 $ 1,792 Deposits paid for securities borrowed and deposits received for securities loaned are recorded at the amount of cash collateral advanced or received. Deposits paid for securities borrowed transactions require the Company to deposit cash with the lender. With respect to deposits received for securities loaned, the Company receives collateral in the form of cash in an amount generally in excess of the market value of the securities loaned. The Company monitors the market value of the securities borrowed and loaned on a daily basis, with additional collateral obtained or refunded, as necessary. The Company’s securities borrowing and lending is generally done under industry standard agreements (“Master Securities Lending Agreements”) that may allow, following an event of default by either party, the prompt close-out of all transactions (including the liquidation of securities held) and the offsetting of obligations to return cash or securities, as the case may be, by the non‑defaulting party. Events of default under the Master Securities Lending Agreements generally include, subject to certain conditions: (a) failure to timely deliver cash or securities as required under the transaction, (b) a party’s insolvency, bankruptcy, or similar proceeding, (c) breach of representation, and (d) a material breach of the agreement. The counterparty that receives the securities in these transactions generally has unrestricted access in its use of the securities. For financial statement purposes, the Company does not offset securities borrowed and securities loaned. The following table summarizes the transactions under certain Master Securities Lending Agreements that may be eligible for offsetting if an event of default occurred and a right of offset was legally enforceable (dollars in thousands): Gross Amounts Net Amounts Collateral Offset in the Presented in the Received or Gross Amounts of Consolidated Consolidated Pledged Recognized Assets/ Statement of Statement of (including Net (Liabilities) Financial Condition Financial Condition Cash) Amount As of December 31, 2017: Deposits paid for securities borrowed $ 4,246 $ — $ 4,246 $ 4,246 $ — Deposits received for securities loaned (4,245) — (4,245) (4,229) (16) As of December 31, 2016: Deposits paid for securities borrowed $ 374 $ — $ 374 $ 374 $ — Deposits received for securities loaned (35,198) — (35,198) (34,245) (953) In accordance with ASU 2014-11, Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures, the gross obligations of deposits received for securities loaned was $4.2 million and $34.3 million for equity securities at December 31, 2017 and 2016, respectively. The remaining contractual maturities of these agreements were overnight and continuous.

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2017
Premises and Equipment
Premises and Equipment	(11) Premises and Equipment The following is a summary of premises and equipment at December 31 (dollars in thousands): 2017 2016 Furniture, fixtures and equipment $ 149,366 $ 157,770 Leasehold improvements 45,543 52,440 194,909 210,210 Less: accumulated depreciation and amortization 140,949 150,877 Total $ 53,960 $ 59,333 Depreciation and amortization expense relating to premises and equipment amounted to $18.3 million, $16.5 million and $16.3 million during the years ended December 31, 2017, 2016 and 2015, respectively, and are included in occupancy and equipment expense in the Consolidated Statements of Operations. During 2017, premises and equipment costs and related accumulated depreciation and amortization were reduced by $30.6 million and $10.2 million, respectively, for assets that are no longer in use. During 2017, the Company also wrote off leasehold assets of $7.5 million, net of accumulated depreciation, related to consolidation of its New York headquarters from three floors to two floors.

Capitalized Software

Capitalized Software	12 Months Ended
	Dec. 31, 2017
Capitalized Software
Capitalized Software	(12) Capitalized Software The following is a summary of capitalized software costs at December 31 (dollars in thousands): 2017 2016 Capitalized software costs $ 86,316 $ 82,877 Less: accumulated amortization 45,057 44,271 Total $ 41,259 $ 38,606 Software costs totaling $27.8 million and $24.6 million were capitalized in 2017 and 2016, respectively, related to the continued development of new features and functionalities across the entire ITG product line. During 2017, capitalized software costs and related accumulated amortization were each reduced by $25.0 million for fully amortized costs. Other general and administrative expenses in the Consolidated Statements of Operations included $25.6 million, $25.1 million and $24.6 million related to the amortization of capitalized software costs in 2017, 2016 and 2015, respectively. As of December 31, 2017 and 2016, there were no capitalized software costs not subject to amortization.

Accounts Payable and Accrued Ex

Accounts Payable and Accrued Expenses	12 Months Ended
	Dec. 31, 2017
Accounts Payable and Accrued Expenses
Accounts Payable and Accrued Expenses	(13) Accounts Payable and Accrued Expenses The following is a summary of accounts payable and accrued expenses at December 31 (dollars in thousands): December 31, December 31, 2017 2016 Accrued research payables $ 51,275 $ 45,826 Accrued compensation and benefits 37,911 34,526 Accrued settlement costs — 24,450 Accrued rent 14,821 19,061 Trade payables 20,820 14,474 Deferred revenue 8,057 7,643 Deferred compensation 2,525 3,262 Accrued restructuring 6 3,157 Accrued transaction processing 3,257 3,230 Other 27,823 18,714 Total $ 166,495 $ 174,343

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2017
Borrowings
Borrowings	(14) Borrowings Short-term Bank Loans The Company’s international securities clearing and settlement activities are funded with operating cash or with short-term bank loans in the form of overdraft facilities. At December 31, 2017, there was $101.4 million outstanding under these facilities at a weighted average interest rate of approximately 2.33% associated with international settlement activities. In the U.S., securities clearing and settlement activities are funded with operating cash, securities loaned or with short-term bank loans under the Credit Agreement described below. ITG Inc., as borrower, and Investment Technology Group, Inc. (the “Parent Company”), as guarantor, maintained a $150 million 364‑day revolving credit agreement (the “2017 Credit Agreement”) with a syndicate of banks and JPMorgan Chase Bank, N.A., as Administrative Agent that matured in January 2018. The purpose of this credit line was to provide liquidity for the Company’s U.S. brokerage operations to satisfy clearing margin requirements and to finance temporary positions from delivery failures or non-standard settlements. As a result, the Parent Company had additional flexibility with its existing cash and future cash flows from operations, including to selectively invest in growth initiatives and to return capital to stockholders. Depending on the borrowing base, availability under the 2017 Credit Agreement was limited to either (i) a percentage of the clearing deposit required by the National Securities Clearing Corporation, or (ii) a percentage of the market value of temporary positions pledged as collateral. Under the 2017 Credit Agreement, interest accrued at a rate equal to (a) a base rate, determined by reference to the federal funds rate plus (b) a margin of 2.50%. Available but unborrowed amounts under the 2017 Credit Agreement were subject to an unused commitment fee of 0.75%. Among other restrictions, the terms of the 2017 Credit Agreement included (a) negative covenants related to liens, (b) financial covenant requirements for maintaining a consolidated leverage ratio (as defined) and a liquidity ratio (as defined), as well as requirements for maintaining minimum levels of tangible net worth (as defined) and regulatory capital (as defined), and (c) restrictions on investments, dispositions and other restrictions customary for financings of this type. The events of default under the 2017 Credit Agreement included, among others, payment defaults, cross defaults with certain other indebtedness, breaches of covenants, loss of collateral, judgments, and changes in control and bankruptcy events. In the event of non-payment, the 2017 Credit Agreement required ITG Inc. to pay incremental interest at the rate of 2.0%. In the event of a default and depending on the nature thereof, the commitments would either automatically terminate and all unpaid amounts immediately become due and payable, or the lenders may in their discretion terminate their commitments and declare due all unpaid amounts outstanding. On January 26, 2018, ITG Inc., as borrower, and Parent Company, as guarantor, entered into a new $150 million 364-day revolving credit agreement with a syndicate of banks and JPMorgan Chase Bank, N.A., as Administrative Agent expiring on January 25, 2019 with essentially the same terms as the 2017 Credit Agreement (see Note 24, Subsequent Events ). At December 31, 2017 and 2016, there were no amounts outstanding under the Company’s credit agreements. Term Debt At December 31, term debt is comprised of the following (dollars in thousands): December 31, December 31, 2017 2016 Term loans $ 3,104 $ 3,098 Obligations under capital lease — 3,269 Total $ 3,104 $ 6,367 On December 21, 2017, the Company entered into a three year, $0.7 million note and security agreement with Hewlett-Packard Financial Services (“H-P Veritas Loan”), under which purchases of new software licenses and support were financed. The loan principal is payable in three installments of $239,996 in January 2018, and $229,994 in both January and March of 2019. The loan does not accrue interest. On December 30, 2015, the Company entered into a five year, $3.6 million note and security agreement with Hewlett-Packard Financial Services (“H-P Loan”), under which purchases of new server equipment, software license fees, maintenance fees and fees for other services were financed. The loan principal is payable in twenty quarterly installments of $195,000 beginning in April 2016 and accrues interest at 2.95%. The reductions to the principal balance applying the interest method to the required payments are as follows (dollars in thousands): Aggregate Year Amount 2018 $ 715 2019 737 2020 759 2021 193 $ 2,404 On June 1, 2011, Parent Company as borrower, entered into a $25.5 million Master Loan and Security Agreement (the “Equipment Loan Agreement”) with Banc of America Leasing & Capital, LLC (“Bank of America”). The four‑year term loan established under this agreement (the “Equipment Loan”) was secured by a security interest in existing furniture, fixtures and equipment owned by the Parent Company and certain U.S. subsidiaries as of June 1, 2011. The Equipment Loan was payable in monthly principal installments of $530,600 through May 2015 and accrued interest at 3.0% plus the average one month London Interbank Offered Rate for dollar deposits. Along with the Equipment Loan Agreement, Parent Company entered into a $5.0 million master lease facility with Bank of America (“Master Lease Agreement”), under which purchases of new equipment were financed. Each equipment lease under the Master Lease Agreement is structured as a capital lease and has a separate 48‑month term from its inception date, at the end of which Parent Company may purchase the underlying equipment for $1. At December 31, 2017 and 2016, all capital leases under this facility were fully paid. On August 10, 2012, Parent Company entered into a $25.0 million master lease facility with BMO Harris Equipment Finance Company (“BMO”) to finance equipment and construction expenditures related to the build‑out of the Company’s new headquarters in lower Manhattan. The original amount borrowed of $21.2 million had a 3.39% fixed‑rate term financing structured as a capital lease with a 48‑month term that began upon the substantial completion of the build-out, at the end of which Parent Company may purchase the underlying assets for $1. At December 31, 2017, the loan outstanding under the BMO facility was fully paid. Interest expense on the 2017 Credit Agreement, the Equipment Loan Agreement, the Master Lease Agreement and the BMO facility, including commitment fees and the amortization of debt issuance costs totaled $2.0 million, $2.2 million and $1.8 million in 2017, 2016 and 2015, respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income	(15) Accumulated Other Comprehensive Income The components and allocated tax effects of other comprehensive income for the periods ended December 31, 2017 and December 31, 2016 are as follows (dollars in thousands): Year Ended December 31, 2017 Balance at December 31, 2016 $ (33,977) Other comprehensive income 12,580 Balance at December 31, 2017 $ (21,397) Year Ended December 31, 2016 Balance at December 31, 2015 $ (19,495) Other comprehensive loss before reclassifications (13,416) Amounts reclassified from accumulated other comprehensive loss (1) (1,066) Net current-period other comprehensive loss (14,482) Balance at December 31, 2016 $ (33,977) (1) In the third quarter of 2016, the Company substantially completed the liquidation of its investment in its Israel entity that ceased operations in December 2013. During the Company’s period of ownership and through December 2013, the Company had $1.1 million in accumulated foreign exchange translation gains as a component of equity, which have been reclassified during the year ended December 31, 2016 as a gain that reduced other general and administrative expenses in the Consolidated Statement of Operations. Deferred taxes have not been provided on the cumulative undistributed earnings of foreign subsidiaries or the cumulative translation adjustment related to those investments since the Company was subject to a one-time inclusion in 2017 U.S. taxable income of all foreign earnings and profits not previously taxed in the U.S. pursuant to the Tax Cuts and Jobs Act.

Net Capital Requirement

Net Capital Requirement	12 Months Ended
	Dec. 31, 2017
Net Capital Requirement
Net Capital Requirement	(16) Net Capital Requirement ITG Inc., AlterNet and ITG Derivatives are subject to the SEC’s Uniform Net Capital Rule (Rule 15c3‑1), which requires the maintenance of minimum net capital. ITG Inc. has elected to use the alternative method permitted by Rule 15c3‑1, which requires that ITG Inc. maintain minimum net capital equal to the greater of $1.0 million or 2% of aggregate debit balances arising from customer transactions, as defined. AlterNet and ITG Derivatives have elected to use the basic method permitted by Rule 15c3‑1, which requires that they each maintain minimum net capital equal to the greater of 6 2 / 3 % of aggregate indebtedness or $100,000. Dividends or withdrawals of capital cannot be made if capital is needed to comply with regulatory requirements. Net capital balances and the amounts in excess of required net capital at December 31, 2017 for the U.S. Operations are as follows (dollars in thousands): Net Capital Excess U.S. Operations ITG Inc. $ 86,165 $ 85,165 AlterNet 4,300 4,200 ITG Derivatives 579 479 As of December 31, 2017, ITG Inc. had $9.2 million of cash in a Special Reserve Bank Account for the benefit of customers under the Customer Protection Rule pursuant to SEC Rule 15c3‑3, Computation for Determination of Reserve Requirements and $2.5 million under PABs. In addition, the Company’s Canadian, European and Asia Pacific Operations have subsidiaries with regulatory capital requirements. The regulatory net capital balances and amount of regulatory capital in excess of the minimum requirements applicable to each business at December 31, 2017, is summarized in the following table (dollars in thousands): Net Capital Excess Canadian Operations Canada $ 24,450 $ 24,050 European Operations Ireland 46,030 12,278 U.K. 2,036 1,025 Asia Pacific Operations Australia 27,008 17,591 Hong Kong 5,993 5,538 Singapore 1,121 1,047 In the first quarter 2017, the Company migrated from self-clearing in Hong Kong to the use of a third-party clearer that settles trades executed in Hong Kong on behalf of ITG Australia Limited. During the second quarter of 2017, the Company received regulatory approval for a change in the method used to determine its capital requirements in Europe following an extensive review it initiated with its local regulator.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity
Stockholders' Equity	(17) Stockholders’ Equity The Company’s current policy, which is reviewed continually, is to retain earnings to finance the operations and expansion of its businesses as well as return capital to stockholders through share repurchases and dividends on common stock. Stock Repurchase Program To facilitate its stock repurchase program, designed to return value to stockholders and minimize dilution from stock issuances, the Company repurchases shares in the open market and through automatic share repurchase programs under SEC Rule 10b5-1. The table below summarizes the Company’s share repurchases beginning January 1, 2015 under its Board of Directors’ authorizations: Amount Shares Authorized Total Remaining Shares Repurchased by Board Shares Under Board Under Board Expiration (Shares in Repurchased Authorization Authorization Repurchase Program Authorization Date Date millions) (millions) (millions) 2017 2016 2015 May 2013 none 4.0 4.0 — — — 0.8 October 2014 none 4.0 3.4 0.6 0.9 1.3 1.2 Total shares repurchased under authorization 0.9 1.3 2.0 Cost (millions) $ 16.9 $ 22.1 $ 42.0 Average share price $ 19.13 $ 16.55 $ 21.10 The Company also repurchased approximately 0.5 million, 0.4 million and 0.4 million shares of common stock from employees, respectively, during each of 2017, 2016 and 2015 to satisfy the minimum statutory employee withholding tax upon the net settlement of restricted stock unit awards. In February 2018, the Company’s Board of Directors increased the share repurchase authorization (see Note 24, Subsequent Events ). Dividend Program In 2015, the Company’s Board of Directors initiated a dividend program under which the Company began to pay quarterly dividends, subject to quarterly declarations by the Board of Directors. During 2017, the Board of Directors declared and the Company paid quarterly cash dividends of $0.07 per share totaling $9.2 million in the aggregate and issued stock dividends of $0.1 million.

Off-Balance Sheet Risk and Conc

Off-Balance Sheet Risk and Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2017
Off-Balance Sheet Risk and Concentration of Credit Risk
Off-Balance Sheet Risk and Concentration of Credit Risk	(18) Off-Balance Sheet Risk and Concentration of Credit Risk The Company is a member of various U.S. and non-U.S. exchanges and clearing houses that trade and clear, respectively, equities and/or derivative contracts. Associated with the Company’s membership, the Company may be required to pay a proportionate share of financial obligations of another member who may default on its obligations to the exchanges or the clearing house. While the rules governing different exchange or clearing house memberships vary, in general, the Company’s obligations would arise only if the exchanges and clearing houses had previously exhausted other remedies. The maximum potential payout under these memberships cannot be estimated. The Company has not recorded any contingent liability in the consolidated financial statements for these agreements and believes that any potential requirement to make payments under these agreements is remote. In the ordinary course of business, the Company guarantees obligations of subsidiaries which may arise from third-party clearing relationships and trading counterparties. The activities of the subsidiaries covered by these guarantees are included in the Company’s consolidated financial statements. The Company is also subject to indemnification provisions within agreements with third-party clearing brokers in certain jurisdictions whereby the Company is obligated to reimburse the clearing broker, without limit, for losses incurred due to a counterparty’s failure to satisfy its contractual obligations. The Company’s customer financing and securities settlement activities may require the Company to pledge customer securities as collateral in support of various secured financing transactions such as bank loans. In the event the financing counterparty is unable to meet its contractual obligation to return customer securities pledged as collateral, the Company may be exposed to the risk of acquiring the securities at prevailing market prices in order to satisfy its customer obligations. The Company controls this risk by monitoring the market value of securities pledged on a daily basis and by requiring adjustments of collateral levels in the event of excess market exposure. Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash and cash equivalents, securities owned at fair value, receivables from brokers, dealers and clearing organizations and receivables from customers. Cash and cash equivalents and securities owned, at fair value are deposited with high credit quality financial institutions. In connection with customer settlement activities, the Company loans securities temporarily to other brokers. The Company receives cash as collateral for the securities loaned. Increases in security prices may cause the market value of the securities loaned to exceed the amount of cash received as collateral. In the event the counterparty to these transactions does not return the loaned securities, the Company may be exposed to the risk of acquiring the securities at prevailing market prices in order to satisfy its client obligations. The Company controls this risk by requiring credit approvals for counterparties, by monitoring the market value of securities loaned on a daily basis, and by requiring additional cash as collateral or returning collateral when necessary. The Company also borrows securities temporarily from other brokers in connection with customer settlement activities. The Company deposits cash as collateral for the securities borrowed. Decreases in security prices may cause the market value of the securities borrowed to fall below the amount of cash deposited as collateral. In the event the counterparty to these transactions does not return collateral, the Company may be exposed to the risk of selling the securities at prevailing market prices. The Company controls this risk by requiring credit approvals for counterparties, by monitoring the collateral values on a daily basis, and by depositing additional collateral with counterparties or receiving cash when deemed necessary. The Company may at times maintain inventories in equity securities on both a long and short basis. Whereas long inventory positions represent the Company’s ownership of securities, short inventory positions represent obligations of the Company to deliver specified securities at a contracted price, which may differ from market prices prevailing at the time of completion of the transaction. Accordingly, both long and short inventory positions may result in losses or gains to the Company as market values of securities fluctuate. To mitigate the risk of losses, long and short positions are marked to market daily and are continuously monitored by the Company.

Employee and Non-Employee Direc

Employee and Non-Employee Director Stock and Benefit Plans	12 Months Ended
	Dec. 31, 2017
Employee and Non-Employee Director Stock and Benefit Plans
Employee and Non-Employee Director Stock and Benefit Plans	(19) Employee and Non‑Employee Director Stock and Benefit Plans The 2007 Omnibus Equity Compensation Plan (the “2007 Plan”) was approved by the Company’s stockholders and became effective on May 8, 2007 (the “Effective Date”) and was last amended and restated effective June 8, 2017. As of the Effective Date, the Amended and Restated Investment Technology Group, Inc. Directors’ Retainer Fee Subplan (the “Directors’ Retainer Fee Subplan”) and the Amended and Restated Investment Technology Group, Inc. Directors’ Equity Subplan (the “Directors’ Equity Subplan,” and collectively with the Directors’ Retainer Fee Subplan, the “Subplans”) were merged with and into the 2007 Plan. Since the Effective Date, the Subplans have continued to be, and shall continue to be, in effect as subplans of the 2007 Plan and grants and/or deferrals may continue to be made. In October 2008, the Compensation Committee of the Company's Board of Directors adopted the Equity Deferral Award Program, another subplan under the 2007 Plan. This subplan, last amended and restated on January 23, 2017, is now known as the Variable Compensation Stock Unit Award Program Subplan, and continues to be a subplan under the 2007 Plan (the “VCSUA Subplan”). As of December 31, 2017, there were 3,123,105 shares of common stock remaining available for issuance under the 2007 Plan. Shares of common stock which are attributable to awards which have expired, terminated, cash settled or been canceled or forfeited during any calendar year are generally available for issuance or use in connection with future awards. Shares of common stock surrendered in payment of the exercise price of a stock option and shares withheld or surrendered for payment of taxes are not available for re-issuance under the 2007 Plan. Options outstanding as of December 31, 2017 that have been granted under the 2007 Plan are exercisable on dates ranging through January 2024. The 2007 Plan will remain in effect until June 10, 2025, unless terminated, or extended, by the Board of Directors with the approval of the Company’s stockholders. After this date, no further awards shall be granted pursuant to the 2007 Plan, but previously‑granted awards will remain outstanding in accordance with their applicable terms and conditions. In January 2006, the Board of Directors adopted the Directors’ Equity Subplan which became effective January 1, 2006 and merged into the 2007 Plan as referenced above. The Directors’ Equity Subplan was last amended and restated on January 23, 2017. The Directors’ Equity Subplan provides for the grant of restricted stock unit awards to non‑employee directors of the Company. Under the Directors’ Equity Subplan, a newly appointed non‑employee director will be granted restricted stock unit awards valued at $100,000 at, or shortly after, the time of appointment to the Board of Directors. Such initial restricted stock unit awards will vest annually in three equal installments, beginning on the first anniversary of the date of grant so long as the director has continued to serve on the Board of Directors from the grant date to the applicable vesting date. In addition, non‑employee directors are granted restricted stock unit awards annually on the day of each of the Company’s annual meetings of stockholders at which directors are elected or reelected by the Company’s stockholders. The value of these annual restricted stock unit awards is determined by the Compensation Committee. Currently, the value of restricted stock unit awards granted to the Chairman of the Board of Directors is $120,000 and the value of restricted stock unit awards granted to the other non-employee directors is $80,000. Such annual restricted stock unit awards vest in full on the day immediately preceding the Company’s next annual meeting of stockholders at which directors are elected or reelected by the Company’s stockholders so long as the director has continued to serve on the Board of Directors from the grant date through the vesting date. Under the 2007 Plan, the Company is permitted to grant time‑based stock options, in addition to performance-based option awards to employees and directors. In 2016, the Company granted time-based options for 196,851 shares to the Company’s new Chief Executive Officer. These stock options have an eight-year term and vest annually in three equal installments, beginning on the first anniversary of the grant date, if the Chief Executive Officer remains continuously employed by the Company, and is in good standing on, each applicable vesting date. The Company did not grant any option awards under the 2007 Plan during 2015 or 2017. The Company recognizes share‑based compensation expense (see Note 2, Summary of Significant Accounting Policies ) for time‑based option awards over the vesting period. The tables below summarize the Company’s outstanding stock options as of December 31, 2017, 2016 and 2015 and changes during the years then ended: Weighted Options Number of Average Outstanding Shares Exercise Price Outstanding at December 31, 2014 306,853 $ 17.23 Granted — — Exercised (71,455) 16.26 Forfeited (192,733) 18.71 Outstanding at December 31, 2015 42,665 $ 12.17 Granted 196,851 16.18 Exercised (42,665) 12.17 Forfeited — — Outstanding at December 31, 2016 196,851 $ 16.18 Granted — — Exercised — — Forfeited — — Outstanding at December 31, 2017 196,851 $ 16.18 Amount exercisable at December 31, 2017 65,630 $ 16.18 2016 — $ — 2015 42,665 $ 12.17 Options Outstanding Options Exercisable Weighted Average Weighted Weighted Remaining Average Average Number Contractual Exercise Number Exercise Exercise Price Outstanding Life (Years) Price Exercisable Price $ 16.18 196,851 6.04 $ 16.18 65,630 $ 16.18 For the years ended December 31, 2017 and 2016, the Company recorded share-based compensation expense of $0.3 million and $0.3 million, respectively, related to outstanding stock options, which had no income tax benefit in 2017 and was offset by a related income tax benefit of $0.1 million in 2016. For the year ended December 31, 2015, the Company recorded no share-based compensation expense related to outstanding stock options. There were 65,630 stock options currently exercisable at December 31, 2017. The weighted average remaining contractual term of stock options currently exercisable is 6.0 years. All of the stock options outstanding at December 31, 2017 were time‑based. Prior to the adoption of ASU 2016-09, Improvements to Employee Share-Based Payment Accounting , the provision for income taxes excluded excess current tax benefits related to the exercise of stock options. Effective January 1, 2017, all subsequent excess tax benefits and deficiencies are recognized in the statement of operations as an increase or decrease in income taxes when the awards vest or are settled . See discussion in Note 2, Summary of Significant Accounting Policies. During 2017, there were no exercises of stock options and therefore no corresponding current tax benefits or deficiencies. During 2016, the exercise of 42,655 stock options gave rise to an excess current tax benefit of $0.1 million. During 2015, the exercise of 71,455 stock options gave rise to an excess current tax benefit of less than $0.1 million, however, this amount was offset by a tax shortfall on exercises and cancellations totaling $0.6 million. The following table summarizes information about stock options at December 31, 2017, 2016 and 2015: ($ in thousands) 2017 2016 2015 Total intrinsic value of stock options exercised $ — $ 220 $ 370 Weighted average grant date fair value of stock options granted during period, per share — 16.18 — Cash received from stock option exercises $ — $ 208 $ 298 The total intrinsic value for outstanding and exercisable stock options at December 31, 2017 was $0.6 million and $0.2 million, respectively. As of December 31, 2017, there was $0.3 million of unrecognized compensation costs related to outstanding stock options. These costs are expected to be recognized ratably over a weighted average period of approximately 1.0 year. Under the 2007 Plan, the Company is permitted to grant restricted stock unit awards to employees. Generally, and except for awards granted under the VCSUA Subplan, restricted stock unit awards vest in one of the following manners: (a) one-third on the second anniversary of the grant date and two-thirds on the third anniversary of the grant date, (b) cliff vesting on the third anniversary of the grant date, (c) for new hire awards only, vesting terms that closely parallel the vesting terms of any awards that the new hire will forfeit upon joining the Company, except that no such new hire award or portion thereof shall vest prior to the one-year anniversary of the date of grant unless otherwise permitted by the 2007 Plan, or (d) serial vest on each of the second, third and fourth anniversaries of the date of grant so long as the award recipient is employed on the applicable vesting date and the 90-day average of the Company’s common stock price preceding each of the vesting dates is greater than the 90-day average of the Company’s common stock price preceding the grant date (market-based restricted stock units). Accordingly, not all restricted stock units awarded will vest and be delivered. The Company recognizes share-based compensation expense (see Note 2, Summary of Significant Accounting Policies ) over the vesting period. Under the VCSUA Subplan, beginning in January 2017, each eligible participant was granted a number of basic stock units on the date the year-end variable compensation is communicated to participants equal to (i) the amount by which the participant’s variable compensation is reduced as determined by the Compensation Committee of the Board of Directors, divided by (ii) the fair market value of a share of the Company’s common stock on the date of grant. Prior to January 2017, the basic stock units were granted on the date the year-end cash bonus was paid to participants. In addition, each participant is granted an additional number of matching stock units on the date of grant equal to 10% of the number of time-based or market-based basic stock units granted. Basic stock units under the VCSUA Subplan that are time-based typically vest in equal annual installments on each of the first, second and third anniversaries of the date of grant, if the participant remains continuously employed by the Company, and is in good standing on, each applicable vesting date. Time-based matching stock units will vest 100% on the third anniversary of the date of grant, if the participant remains continuously employed by the Company through, and is in good standing on, such vesting date. Basic units under the VCSUA Subplan that are market-based (which were granted in February 2014 to members of senior management) vest in equal installments on each of the second, third and fourth anniversaries of the date of grant so long as the award recipient is employed on the applicable vesting date and the 90‑day average of the Company’s common stock price preceding each of the vesting dates is greater than the 90‑day average of the Company’s common stock price preceding the grant date. Matching stock units on market-based awards will vest 100% on the fourth anniversary of the date of grant so long as the award recipient is employed on the applicable vesting date and the 90‑day average of the Company’s common stock price preceding the vesting date is greater than the 90‑day average of the Company’s common stock price preceding the grant date. The Company has also issued to members of its senior management basic stock units under the VCSUA that vest in one of the following manners: (a) for awards granted in February 2015, in equal installments on each of the first, second, and third anniversaries of the date of grant based upon the level of the Company’s adjusted return-on-equity (“ROE”) achieved for each of the three fiscal years, respectively, that ends immediately prior to the applicable vesting date, (b) for awards granted in February 2016, in equal installments on each of the second and third anniversaries of the date of grant based upon the level of ROE achieved for each of the two fiscal years, respectively, that ends immediately prior to the applicable vesting date (each ROE-based restricted stock units) or (c) for awards granted in February 2017, between January 1, 2019 and February 5, 2019, the Compensation Committee will determine and certify the extent to which the basic units have been earned, if at all, based on the levels of revenue and pre-tax margin achieved for the 2018 fiscal year, and such earned basic units shall be divided into two equal installments, with the first installment vesting on February 5, 2019 and the second installment vesting on February 5, 2020 (performance-based restricted stock units) . In addition to the performance criteria being achieved under each of these awards, the participant must remain continuously employed by the Company through, and be in good standing on, each applicable vesting date. The number of ROE-based restricted basic stock units awarded will be earned in each of the relevant performance periods if the target ROE is achieved at 100% and such number may increase or decrease if the actual ROE achieved is above or below the target ROE. In addition, certain senior employees have received matching ROE-based restricted stock units and such awards vest on the third anniversary of the date of grant based upon the average of the ROE achieved during the three-year period that ends immediately prior to the applicable vesting date. The number of matching ROE-based restricted stock units awarded will be earned if the target average ROE is achieved at 100% and such number may increase or decrease if the actual average ROE achieved is above or below the target average ROE. The number of performance-based restricted stock units earned is determined pursuant to a payout matrix established by the Committee that sets forth a range of payout percentages relative to the Company’s actual revenue and pre-tax margin results achieved for the 2018 fiscal year, with each performance metric weighted equally. All vested stock units are settled in shares of ITG common stock within 30 days after the date on which such stock units vest. During 2016, the Company granted two Inducement Awards in conjunction with the hiring of its new Chief Executive Officer, which replaced awards he forfeited at his former employer. Under the first inducement award, the Chief Executive Officer was granted 135,353 restricted stock units that vest in three equal annual installments beginning on the first anniversary of the grant date. Under the second inducement award, the Chief Executive Officer was granted 156,051 restricted stock units which vested on the following vesting dates: (i) 38% vested on January 31, 2016 and were subject to a 12-month holding requirement; (ii) 41% vested on January 31, 2017; and (iii) the remaining 21% vested on January 31, 2018. The Company recorded share‑based compensation expense of $19.6 million, $24.9 million and $16.4 million for the years ended December 31, 2017, 2016 and 2015, respectively, related to restricted stock unit awards which were offset by related income tax benefits of approximately $0.9 million, $8.9 million and $6.6 million, respectively. A summary of the status of the Company’s restricted stock unit awards as of December 31, 2017, 2016 and 2015 and changes during the years then ended are presented below: Number of Shares Underlying ROE-Based, Number of Market-Based or Shares Weighted Performance- underlying Time- Average Based Restricted Based Restricted Total Number of Grant Date Stock Units Stock Units Shares Fair Value Outstanding at December 31, 2014 438,022 2,221,206 2,659,228 $ 13.51 Granted 263,766 1,932,425 2,196,191 18.79 Vested (97,112) (1,061,935) (1,159,047) 13.49 Forfeited (227,201) (298,135) (525,336) 16.10 Outstanding at December 31, 2015 377,475 2,793,561 3,171,036 $ 16.75 Granted 228,895 1,437,021 1,665,916 16.16 Vested (73,243) (968,995) (1,042,238) 16.06 Forfeited (190,757) (540,693) (731,450) 16.88 Outstanding at December 31, 2016 342,370 2,720,894 3,063,264 $ 16.63 Granted 140,796 1,118,596 1,259,392 19.81 Vested (51,498) (1,279,523) (1,331,021) 16.60 Forfeited (38,324) (45,766) (84,090) 18.99 Outstanding at December 31, 2017 393,344 2,514,201 2,907,545 $ 18.10 At December 31, 2017, 45,065 of the outstanding awards were market‑based restricted stock units, 207,483 were ROE-based restricted stock units and 140,796 were performance-based restricted stock units. On May 27, 2016, the Company sold Investment Research (See Note 4, Divestitures and Acquisitions ). Upon the closing of the transaction, the Company accelerated the vesting of 226,802 restricted stock unit awards held by employees that were part of Investment Research and are included in the table above. The cost to modify the vesting schedule of these shares resulted in an expense reversal of $0.7 million that is included as part of the gain in other revenues in the Consolidated Statement of Operations. On December 22, 2015, the Company sold its energy research operations. Upon the closing of the transaction, the Company accelerated the vesting of 113,718 restricted stock unit awards held by employees that were part of the energy research business and are included in the table above. The cost to modify the vesting schedule of these shares was $1.4 million and is included as a direct cost of the sale that reduced the gain included in other revenues in the Consolidated Statement of Operations. As of December 31, 2017, there was $25.8 million of total unrecognized compensation cost related to outstanding restricted stock unit awards. These costs are expected to be recognized over a weighted average period of approximately 1.3 years. During 2017, restricted stock unit awards with a fair value of approximately $21.9 million vested. Prior to the adoption of ASU 2016-09, Improvements to Employee Share-Based Payment Accounting , the provision for income taxes excluded excess current tax benefits related to the vesting of restricted share units. Effective January 1, 2017 all subsequent excess tax benefits and deficiencies are recognized in the statement of operations. See discussion in Note 2, Summary of Significant Accounting Policies. For the year ended December 31, 2017, the excess tax benefits totaled $1.5 million and tax shortfalls (arising from cancellations or deficits due to the vest date fair market value being less than the grant date fair market value) were $0.1 million. For the year ended December 31, 2016, the excess tax benefits totaled $0.8 million while tax shortfalls were $0.7 million. For the year ended December 31, 2015, the excess tax benefits totaled $2.9 million while tax shortfalls were $0.3 million. For the years 2016 and 2015, such tax benefits are reflected as an increase in additional paid-in capital while tax shortfalls arising from the tax deduction being less than the cumulative book compensation cost is reflected as a decrease in additional paid-in capital. Under the 2007 Plan and the VCSUA Subplan, the Company is permitted to grant phantom share awards. Phantom share awards vest like any other award granted under the 2007 Plan and VCSUA Subplan as described above and are settled in cash. The Company recognizes share‑based compensation expense (see Note 2, Summary of Significant Accounting Policies ) over the applicable vesting period. For the years ended December 31, 2016 and 2015, the Company recorded share‑based compensation expense of $0.1 million and $2.2 million, respectively, related to phantom share awards offset by related tax benefits of less than $0.1 million and $0.8 million, respectively. A summary of the status of the Company’s phantom share awards as of December 31, 2016 and 2015 and changes during the years then ended are presented below: Weighted Average Number of Grant Date Shares Fair Value Outstanding at December 31, 2014 358,349 $ 11.61 Granted — — Vested (257,279) 11.58 Forfeited (43,272) 10.99 Outstanding at December 31, 2015 57,798 $ 12.24 Granted — — Vested (57,798) 12.24 Forfeited — — Outstanding at December 31, 2016 — $ — At December 31, 2016, there were no outstanding phantom share awards and none were granted in 2017. The Company discontinued granting phantom share awards effective January 1, 2014 and the remaining awards outstanding vested on February 22, 2016. ITG Employee and Non‑Employee Director Benefit Plans All U.S. employees are eligible to participate in the Investment Technology Group, Inc. Retirement Savings Plan (“RSP”). The RSP applies to all eligible compensation up to the Internal Revenue Service annual maximum which was $270,000 during 2017. Since January 1, 2012, the Company matching contribution applies to 50% of voluntary employee contributions, on a maximum of 4% of eligible compensation per year. The Company may still make discretionary contributions based on consolidated profits. Most of the Company’s international employees are eligible to participate in similar defined contribution plans. The costs for these benefits were approximately $4.3 million, $4.4 million, and $4.9 million in 2017, 2016 and 2015, respectively, and are included in compensation and employee benefits in the Consolidated Statements of Operations. In November 1997, the Board of Directors approved the ITG Employee Stock Purchase Plan (“ESPP”), an employee stock purchase plan qualified under Section 423 of the Internal Revenue Code. The ESPP became effective February 1, 1998 and allows all full‑time employees to purchase shares of ITG common stock at a 15% discount. In accordance with the provisions of ASC 718, the ESPP is compensatory. The Company recorded share‑based compensation expense related to the ESPP of $0.3 million, $0.4 million and $0.3 million for the years ended December 31, 2017, 2016 and 2015, respectively. During 2017, each non‑employee director received a general Board retainer fee of $70,000, with the exception of the Chairman who received $105,000. Each non-employee director was also eligible to receive a Committee Chair retainer fee and Committee member retainer fee depending on their role on the Board’s Committees. Under the Directors’ Retainer Fee Subplan, which was adopted in 2002, these retainer fees are payable, at the election of each director, either in (i) cash, (ii) Company common stock with a value equal to the retainer fee on the grant date or (iii) under a deferred compensation plan which provides deferred share units with a value equal to the retainer fee on the grant date which convert to freely sellable shares when the director retires from the Board of Directors. Directors who chose common stock or deferred share units, in the aggregate, received 11,115 units or shares, 12,363 units or shares, and 13,846 units or shares in 2017, 2016 and 2015, respectively. At December 31, 2017, there were 130,940 deferred share units outstanding, of which 20,485 shares were vested and deferred in 2017. The cost of the Directors’ Retainer Fee Subplan including share based awards and cash fees was approximately $0.8 million, $0.8 million, and $1.2 million in 2017, 2016 and 2015, respectively, and is included in other general and administrative expenses in the Consolidated Statements of Operations.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share
Earnings Per Share	(20) Earnings Per Share The following is a reconciliation of the basic and diluted earnings per share computations (dollars in thousands, except per share amounts): December 31, 2017 2016 2015 Net (loss) income for basic and diluted (loss) income per share $ (39,440) $ (25,918) $ 91,570 Shares of common stock and common stock equivalents: Average common shares used in basic computation 33,009 32,906 33,907 Effect of dilutive securities — — 908 Average common shares used in diluted computation 33,009 32,906 34,815 (Loss) income per share: Basic $ (1.19) $ (0.79) $ 2.70 Diluted $ (1.19) $ (0.79) $ 2.63 For 2017 and 2016, there were no anti-dilutive securities due to the fact that the Company incurred a loss during the year. At December 31, 2015, approximately 0.1 million share equivalents (based on the treasury stock method) were not included in the computation of diluted earnings per share because their effects would have been anti‑dilutive.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Contingencies - Legal Matters
Commitments and Contingencies	(21) Commitments and Contingencies Legal Matters On January 12, 2017, the Company reached a final settlement with the SEC to resolve the SEC’s inquiry into ITG Inc.’s activity with respect to pre-released American Depositary Receipts (“ADRs”), substantially all of which related to ITG Inc.’s matched-book operations. ITG Inc.’s activity in pre-released ADRs was discontinued in the fourth quarter of 2014, with all outstanding transactions completely wound down by the end of 2014. According to the terms of the settlement, the Company paid an aggregate amount of $24.5 million in January 2017, which includes disgorgement of $15.1 million, prejudgment interest of $1.9 million and a civil monetary penalty of $7.5 million. The Company had fully reserved the $24.5 million as of December 31, 2016. The Company is not a party to any pending legal proceedings other than claims and lawsuits arising in the ordinary course of business, except a putative class action lawsuit and a derivative action have been filed with respect to the Company and certain of its current and former directors and/or executives in connection with the Company’s announcement of the SEC matter described in the following paragraph (and other related actions could be filed). On August 12, 2015, the Company reached a final settlement with the SEC in connection with the SEC’s investigation into a proprietary trading pilot operated within AlterNet for sixteen months in 2010 through mid-2011. The investigation was focused on customer disclosures, Form ATS regulatory filings and customer information controls relating to the pilot’s trading activity, which included (a) crossing against sell-side clients in POSIT and (b) violations of Company policy and procedures by a former employee. These violations principally involved information breaches for a period of several months in 2010 regarding sell-side parent orders flowing into ITG’s algorithms and executions by all customers in non-POSIT markets that were not otherwise available to ITG clients. According to the terms of the settlement, the Company paid an aggregate amount of $20.3 million, representing a civil penalty of $18 million, disgorgement of approximately $2.1 million in trading revenues and prejudgment interest of approximately $0.25 million. In connection with the announcement of the SEC investigation regarding AlterNet, two putative class action lawsuits were filed with respect to the Company and certain of its current and former executives and have since been consolidated into a single action captioned In re Investment Technology Group, Inc. Securities Litigation before the U.S. District Court for the Southern District of New York. The complaint alleges, among other things, that the defendants made material misrepresentations or omitted to disclose material facts concerning, among other subjects, the matters that were the subject of the SEC settlement regarding AlterNet and the SEC investigation that led to the SEC settlement. The complaint seeks an unspecified amount of damages under the federal securities laws. On April 26, 2017, the court granted in part and denied in part the Company’s motion to dismiss the complaint and granted the plaintiff leave to file a motion to amend its complaint. On June 12, 2017, the plaintiff filed a motion to amend its complaint against certain of the individual defendants who were dismissed from the case in the court’s April opinion. On November 27, 2015, a purported shareholder of the Company filed a shareholder derivative action captioned Watterson v. Gasser et al. against eleven current or former officers and directors of the Company in the Supreme Court for the State of New York. The Company is named as a nominal defendant, and the plaintiff purports to seek recovery on its behalf. The complaint generally alleges that the individual defendants breached their fiduciary duties to the Company in connection with the matters that were the subject of the SEC settlement regarding AlterNet. While the Company cannot predict the outcome of these lawsuits, the Company intends to defend them as appropriate. No reserve has been established for these lawsuits since the Company is unable to provide a reasonable estimate of any potential liability given the stage of such proceedings. The Company believes, based on information currently available, that the outcome of these lawsuits, individually or in the aggregate, will not likely have a material adverse effect on its consolidated financial position. In light of the inherent uncertainties of such proceedings, an adverse outcome of one or more of such proceedings may have a material impact on the results of operations for any particular period. In addition to the above proceedings, the Company’s broker-dealer subsidiaries are subject to, or involved in, investigations and other proceedings by government agencies and self-regulatory organizations, with respect to which the Company is cooperating. Such investigations and other proceedings may result in judgments, settlements, fines, disgorgements, penalties, injunctions or other relief. Given the inherent uncertainties and the current stage of these inquiries, and the Company’s ongoing reviews, the Company is unable to predict the outcome of these matters at this time. Lease Commitments The Company has entered into lease and sublease agreements with third parties for certain offices and equipment, which expire at various dates through 2030. Rent expense for each of the years ended December 31, 2017, 2016 and 2015 was $11.8 million, $12.7 million and $12.4 million, respectively, and is recorded in occupancy and equipment expense in the Consolidated Statements of Operations. The Company recognizes rent expense for escalation clauses, rent holidays, leasehold improvement incentives and other concessions using the straight‑line method over the minimum lease term. Minimum future rental commitments under non‑cancelable operating leases follow (dollars in thousands): Aggregate Year Ending December 31, Amount 2018 $ 13,514 2019 13,542 2020 12,161 2021 11,559 2022 10,402 2023 and thereafter 60,301 Total $ 121,479 Other Commitments Pursuant to employment arrangements, in the event of termination of employment without cause on December 31, 2017, the Company would be obligated to pay separation payments totaling $6.0 million. Pursuant to contracts expiring through 2022, the Company is obligated to purchase market data, maintenance and other services totaling $63.6 million.

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2017
Segment Reporting
Segment Reporting	(22) Segment Reporting The Company is organized into four geographic operating segments through which the Company’s chief operating decision maker manages the Company’s business. The U.S., Canadian, European and Asia Pacific Operations segments provide the following categories of products and services: · Execution Services — includes (a) liquidity matching through POSIT, our Alternative Trading System (“ATS”), (b) self-directed trading using algorithms (including single stocks and portfolio lists) and smart routing, (c) portfolio trading and single stock sales trading desks providing execution expertise and (d) futures and options trading · Workflow Technology — includes trade order and execution management software applications in addition to network connectivity · Analytics — includes (a) tools enabling portfolio managers and traders to improve pre-trade, real-time and post-trade execution performance, (b) portfolio construction and optimization decisions and (c) securities valuation The accounting policies of the reportable segments are the same as those described in Note 2, Summary of Significant Accounting Policies . The Company allocates resources to, and evaluates the performance of, its reportable segments based on income or loss before income tax expense (benefit). Consistent with the Company’s resource allocation and operating performance evaluation approach, the effects of inter-segment activities are eliminated except in limited circumstances where certain technology related costs are allocated to a segment to support that segment’s revenue producing activities. Commissions and fees revenue for trade executions and commission share revenues are principally attributed to each segment based upon the location of execution of the related transaction except that commissions and fees for trade executions by Canadian clients in the U.S. market are attributed to the Canadian Operations instead of the U.S. Operations. Recurring revenues are principally attributed based upon the location of the client using the respective service. Regional segment results exclude the impact of Corporate activity, which is presented separately and includes investment income from treasury activity, certain non-operating revenues and other gains as well as costs not associated with operating the businesses within the Company’s regional segments. These costs include, among others, (a) the costs of being a public company, such as certain staff costs, a portion of external audit fees, and reporting, filing and listing costs, (b) intangible asset amortization, (c) interest expense, (d) professional fees associated with the Company's global transfer pricing structure, (e) foreign exchange gains or losses and (f) certain non-operating expenses. A summary of the segment financial information is as follows (dollars in thousands): U.S. Canadian European Asia Pacific Operations Operations Operations Operations Corporate Consolidated 2017 Total revenues $ 204,990 $ 63,294 $ 151,472 $ 62,218 $ 1,720 $ 483,694 (Loss) income before income tax (benefit) expense (1) (2) (24,473) 10,608 41,103 11,680 (32,393) 6,525 Identifiable assets 342,487 108,457 274,836 59,076 — 784,856 Capital purchases 13,278 1,183 3,289 1,652 — 19,402 Depreciation and amortization 33,307 2,420 6,094 1,994 1,338 45,153 Non-cash share-based compensation 9,543 2,390 5,267 959 2,079 20,238 2016 Total revenues $ 229,655 $ 61,822 $ 125,945 $ 47,919 $ 3,711 $ 469,052 (Loss) income before income tax expense (benefit) (3) (4) (5) (6) (7) (8) (11,133) 11,564 25,470 1,553 (70,694) (43,240) Identifiable assets 396,419 80,943 236,071 61,852 — 775,285 Capital purchases 15,547 2,549 1,886 1,333 — 21,315 Depreciation and amortization 32,896 2,402 6,741 1,484 — 43,523 Non-cash share-based compensation 10,642 2,383 5,948 925 5,722 25,620 2015 Total revenues $ 285,230 $ 63,028 $ 129,729 $ 48,179 $ 108,637 $ 634,803 Income before income tax expense (9) (10) (11) 16,000 10,643 28,244 1,620 64,719 121,226 Identifiable assets 1,304,995 76,561 262,095 65,371 — 1,709,022 Capital purchases 7,748 2,175 1,334 648 — 11,905 Depreciation and amortization 33,971 2,247 6,560 1,373 — 44,151 Non-cash share-based compensation 10,725 1,466 4,505 866 (895) 16,667 (1) In the fourth quarter of 2017, the Company incurred an $8.1 million charge for the write-off of fixed assets and other costs associated with the consolidation of ITG’s New York office space. (2) In the third quarter of 2017, the Company deemed the remaining value of a customer intangible asset recorded in ITG Derivatives of $0.3 million fully impaired and incurred legal fees related to the planned formation of the Matrix derivatives venture of $0.8 million. (3) In the second quarter of 2016, the Company received insurance proceeds of $2.4 million from its corporate insurance carrier to settle a claim for lost profits arising from an August 2015 outage in its outsourced primary data center in the U.S. Additionally, the Company generated a nominal gain on the completion of the sale of its investment research operations in May 2016. (4) In the second half of 2016, the Company incurred $24.5 million for a settlement with the SEC with respect to an inquiry involving pre-released ADRs and incurred legal and other related costs associated with this matter of $2.9 million. (5) During the second quarter of 2016, the Company incurred restructuring charges of $4.3 million related to (a) the reduction in its single stock sales trading and sales organizations and (b) the closing of its U.S. matched-book securities lending operations and its Canadian arbitrage trading desk. In the fourth quarter of 2016, the Company incurred additional restructuring charges of $5.3 million related to management delayering and the elimination of certain positions. (6) The Company’s current Chief Executive Officer was granted cash and stock awards upon the commencement of his employment in January 2016, a significant portion of which replaced awards he forfeited at his former employer. Due to U.S. tax regulations, only a small portion of the amount expensed for these awards was eligible for a tax deduction. (7) In the first half of 2016, the Company incurred a charge of $4.8 million, net of an insurance recovery of $0.5 million, to settle an arbitration case with its former CEO and incurred legal fees of $2.7 million. In the third quarter of 2016, the Company recorded a reimbursement of $0.9 million of these legal fees from its insurance carrier. (8) In the third quarter of 2016, the Company substantially completed the liquidation of its investment in its Israel entity that ceased operations in December 2013. During the Company’s period of ownership and through December 2013, the Company had accumulated foreign exchange translation gains as a component of equity, which have been reclassified as a gain that reduced other general and administrative expenses in the Consolidated Statement of Operations. (9) In December 2015, the Company completed the sale of the subsidiaries conducting its energy research operations to an affiliate of Warburg Pincus, a global private equity firm, for $120.5 million. The pre-tax gain of $107.7 million is net of a working capital adjustment on the closing balance sheet, direct costs related to the sale and the carrying value of the net assets disposed. (10) In the third quarter of 2015, the Company reached a final settlement with the SEC to pay an aggregate amount of $20.3 million in connection with the SEC’s investigation into a proprietary trading pilot operated during 2010 and 2011. During 2015, the Company incurred $4.9 million in legal and other related costs associated with this matter. (11) In December 2015, the Company completed changes to the internal capital structure of its holding company outside North America to provide continued flexibility for the movement of capital. This amendment accelerated the U.S. taxation of amounts earned outside of North America, resulting in a tax charge of $6.5 million. The table below details the total revenues for the categories of products and services provided by the Company for the years ended December 31, 2017, 2016 and 2015 (dollars in thousands): December 31, 2017 2016 2015 Revenues: Execution Services $ 344,192 $ 328,252 $ 386,158 Workflow Technology 92,533 92,891 94,117 Analytics 45,249 44,198 45,891 Corporate (non-product) 1,720 3,711 108,637 Total Revenues $ 483,694 $ 469,052 $ 634,803 Long‑lived assets, classified by the geographic region in which the Company operates, are as follows (dollars in thousands): 2017 2016 2015 Long-lived Assets at December 31, United States $ 86,345 $ 92,509 $ 97,226 Canada 3,841 6,972 6,357 Europe 26,130 22,883 27,226 Asia Pacific 4,060 3,726 3,162 Total $ 120,376 $ 126,090 $ 133,971 The Company’s long‑lived assets primarily consist of premises and equipment, capitalized software, goodwill, other intangibles and debt issuance costs.

Supplementary Financial Informa

Supplementary Financial Information (unaudited)	12 Months Ended
	Dec. 31, 2017
Supplementary Financial Information (unaudited)
Supplementary Financial Information (unaudited)	(23) Supplementary Financial Information (unaudited) The following tables set forth certain unaudited financial data for the Company’s quarterly operations in 2017 and 2016. The following information has been prepared on the same basis as the annual information presented elsewhere in this report and, in the opinion of management, includes all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the information for the quarterly periods presented. The operating results for any quarter are not necessarily indicative of results for any future period. (Unaudited) December 31, 2017 (Unaudited) December 31, 2016 $ in thousands, expect per share Fourth Third Second First Fourth Third Second First amounts Quarter Quarter Quarter Quarter Quarter Quarter Quarter Quarter Total revenues $ 126,747 $ 114,531 $ 121,581 $ 120,835 $ 119,589 $ 104,185 $ 120,610 $ 124,668 Expenses: Compensation and employee benefits 45,283 46,755 45,994 46,684 42,980 45,127 48,315 52,464 Transaction processing 26,981 23,428 25,482 24,856 24,540 20,799 22,098 22,834 Occupancy and equipment 23,316 14,945 14,680 15,622 14,296 13,849 14,066 13,978 Telecommunications and data processing services 12,132 12,189 12,129 12,027 13,302 13,720 14,848 14,773 Restructuring charges — — — — 5,265 — 4,355 — Other general and administrative 18,957 18,670 17,699 17,315 20,803 37,927 26,014 23,722 Interest expense 496 499 510 520 549 561 572 535 Total expenses 127,165 116,486 116,494 117,024 121,735 131,983 130,268 128,306 (Loss) income before income tax expense (benefit) (418) (1,955) 5,087 3,811 (2,146) (27,798) (9,658) (3,638) Income tax (benefit) expense 2,000 45,012 444 (1,491) (7,862) (3,887) (4,441) (1,132) Net (loss) income $ (2,418) $ (46,967) $ 4,643 $ 5,302 $ 5,716 $ (23,911) $ (5,217) $ (2,506) Basic (loss) income per share $ (0.07) $ (1.42) $ 0.14 $ 0.16 $ 0.18 $ (0.73) $ (0.16) $ (0.08) Diluted (loss) income per share $ (0.07) $ (1.42) $ 0.14 $ 0.16 $ 0.17 $ (0.73) $ (0.16) $ (0.08) Basic weighted average number of common shares outstanding 32,855 33,105 33,125 32,949 32,607 32,725 33,189 33,106 Diluted weighted average number of common shares outstanding 32,855 33,105 34,222 34,130 33,988 32,725 33,189 33,106 Earnings per share for quarterly periods are based on the weighted average common shares outstanding in individual quarters; thus, the sum of earnings per share of the quarters may not equal the amounts reported for the full year. (Unaudited) December 31, 2017 (Unaudited) December 31, 2016 Fourth Third Second First Fourth Third Second First As a percentage of Total Revenues Quarter (a)(b) (c) Quarter (c)(d) Quarter Quarter Quarter (e)(f)(g) Quarter (e) Quarter (h) Quarter (h) Total revenues 100 % 100.0 % 100.0 % 100.0 % 100.0 % 100.0 % 100.0 % 100.0 % Expenses: Compensation and employee benefits 35.7 40.8 37.8 38.6 35.9 43.3 40.1 42.1 Transaction processing 21.3 20.5 21.0 20.6 20.5 20.0 18.3 18.3 Occupancy and equipment 18.4 13.0 12.1 12.9 12.0 13.3 11.7 11.2 Telecommunications and data processing services 9.6 10.6 10.0 10.0 11.1 13.2 12.3 11.8 Restructuring charges — — — — 4.4 — 3.6 — Other general and administrative 15.0 16.3 14.6 14.3 17.4 36.4 21.6 19.0 Interest expense 0.4 0.4 0.4 0.4 0.5 0.5 0.5 0.4 Total expenses 100.4 101.6 95.9 96.8 101.8 126.7 108.1 102.8 (Loss) income before income tax expense (benefit) (0.4) (1.6) 4.1 3.2 (1.8) (26.7) (8.1) (2.8) Income tax (benefit) expense 1.6 39.3 0.4 (1.2) (6.6) (3.7) (3.7) (0.9) Net (loss) income (2.0) % (40.9) % 3.7 % 4.4 % 4.8 % (23.0) % (4.4) % (1.9) % (a) In the fourth quarter of 2017, the Company incurred an $8.1 million charge for the write-off of fixed assets and other costs associated with the consolidation of ITG’s New York office space. (b) In the fourth quarter of 2017, the Company reduced the amount recorded for a deferred tax liability in the U.S. due to the passing of the Tax Cuts and Jobs Act, which lowered the U.S. corporate income tax rate from 35% to 21%. (c) In the third quarter of 2017, the Company determined that it was appropriate to establish a full valuation allowance on its U.S. deferred tax assets, of which $42.3 million related to periods prior to the third quarter of 2017. In the fourth quarter of 2017, the Company reduced the valuation allowance by $0.9 million as a portion of these U.S. deferred tax assets were realized following a tax method change. (d) In the third quarter of 2017, the Company deemed the remaining value of a customer intangible asset recorded in ITG Derivatives of $0.3 million fully impaired and incurred legal fees related to the planned formation of the Matrix derivatives venture of $0.8 million. (e) During the third and fourth quarters of 2016, the Company accrued $22.1 million and $2.4 million, respectively, for a settlement with the SEC with respect to an inquiry involving pre-released ADRs and incurred legal and other related costs associated with this matter of $1.6 million and $1.3 million, respectively. (f) During the fourth quarter of 2016, the Company incurred restructuring charges of $5.3 million related to management delayering and the elimination of certain positions. During the second quarter of 2016, the Company incurred restructuring charges of $4.3 million related to (a) the reduction in its single stock sales trading and sales organizations and (b) the closing of its U.S. matched-book securities lending operations and its Canadian arbitrage trading desk. (g) During the fourth quarter of 2016, the Company resolved a multi-year tax contingency in the U.S. and reduced tax reserves by $7.3 million. (h) During the first and second quarters of 2016, the Company incurred a charge of $4.8 million, net of an insurance recovery of $0.5 million, to settle an arbitration case with its former CEO and incurred legal fees of $2.7 million. In the third quarter of 2016, the Company recorded a reimbursement of $0.9 million of these legal fees from its insurance carrier.

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2017
Subsequent Events
Subsequent Events	(24) Subsequent Events Credit Agreement On January 26, 2018, ITG Inc., as borrower, and Parent Company, as guarantor, entered into a new $150 million 364-day revolving credit agreement with a syndicate of banks and JPMorgan Chase Bank, N.A., as Administrative Agent. The agreement expires on January 25, 2019 and includes essentially the same terms as the 2017 Credit Agreement which it succeeds. Launch of Derivatives Venture Following the receipt of required regulatory approvals and satisfaction of other customary closing conditions in February 2018, the Matrix derivatives execution and technology transaction closed and the venture was launched. As of closing, the Company is carrying the value of the net assets contributed to the Matrix derivatives venture of approximately $2.0 million as an investment in minority interest and is accounting for its share of results under the equity method. Share Repurchase Program On February 15, 2018, the Company’s Board of Directors authorized the repurchase of an additional 4.0 million shares bringing the total number of shares available for repurchase on that date to 4.4 million shares. This additional authorization has no expiration date. The specific timing and amount of repurchases will vary based on various factors including, among others, market conditions and competing needs for the use of capital.

Summary of Significant Accoun33

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The consolidated financial statements represent the consolidation of the accounts of ITG and its subsidiaries in conformity with U.S. GAAP. All intercompany accounts and transactions have been eliminated in consolidation. Investments in unconsolidated companies (generally 20 to 50 percent ownership), in which the Company has the ability to exercise significant influence but neither has a controlling interest nor is the primary beneficiary, are accounted for under the equity method. Investments in entities in which the Company does not have the ability to exercise significant influence are accounted for under the cost method. Under certain criteria indicated in Accounting Standards Codification (“ASC”) 810, Consolidation , a partially‑owned affiliate would be consolidated as a variable interest entity when it has less than a 50% ownership if the Company was the primary beneficiary of that entity. At the present time, there are no interests in variable interest entities.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets, liabilities, revenues and expenses. Actual results could differ from those estimates.
Revenue Recognition	Revenue Recognition Transactions in securities, commissions and fees and related expenses are recorded on a trade date basis. Commissions and fees are derived primarily from (1) commissions charged for trade execution services, (2) income generated from net executions, whereby equity orders are filled at different prices within or at the National Best Bid and Offer and (3) commission sharing arrangements. Recurring revenues are derived from the following primary sources: (1) connectivity fees, (2) software and analytical products and services and (3) maintenance and customer technical support for the Company’s order management system. Prior to the Company’s divestitures of its investment research operations in May 2016 and December 2015, recurring revenues included subscriptions for these services. Substantially all of the Company’s recurring revenue arrangements do not require significant modification or customization of the underlying software. Accordingly, the vast majority of software revenue is recognized pursuant to the requirements of ASC 985, Software . Specifically, revenue recognition from subscriptions, maintenance, customer technical support and professional services commences when all of the following criteria are met: (1) persuasive evidence of a legally binding arrangement with a customer exists, (2) delivery has occurred, (3) the fee is deemed fixed or determinable and free of contingencies or significant uncertainties and (4) collection is probable. Where software is provided under a hosting arrangement, revenue is accounted for as a service arrangement since the customer does not have the contractual right to take possession of the software at any time during the hosting period without significant penalty (or it is not feasible for the customer to run the software on either its own hardware or third party hardware). Subscription agreements for software products generally include provisions that, among other things, allow customers to receive unspecified future software upgrades for no additional fee, as well as the right to use the software products with maintenance for the term of the agreement, typically one to three years. Under these agreements, once all four of the above noted revenue recognition criteria are met, revenue is recognized ratably over the term of the subscription agreement. If a subscription agreement includes an acceptance provision, revenue is not recognized until the earlier of the receipt of written acceptance from the customer or, if not notified by the customer to cancel the license agreement, the expiration of the acceptance period. Revenues for analytical products sold on a subscription basis are recognized when services are rendered provided that persuasive evidence of a legally binding arrangement exists, the fees are fixed or determinable and collectability is reasonably assured. Other revenues include: (1) the net spread on foreign exchange transactions executed on a principal basis to facilitate equity trades by clients in different currencies, as well as on other foreign exchange transactions unrelated to equity trading, (2) non-recurring consulting services, such as one-time implementation and customer training related activities (3) investment income from treasury activity, (4) interest income on securities borrowed in connection with customers’ settlement activities, (5) market gains/losses resulting from temporary positions in securities assumed in the normal course of agency trading (including trade errors and client trade accommodations), (6) non-recurring gains and losses such as divestitures, (7) fees earned for clearing securities transactions on behalf of other broker-dealers, (8) income from principal trading in Canada, including within the Company’s closed arbitrage trading desk (for historical periods up until April 2016) and (9) the net interest spread earned on securities borrowed and loaned transactions within the Company’s closed U.S. matched-book securities lending operations (for historical periods up until June 2016). Revenues from professional services, which are sold as a multiple‑element arrangement with the implementation of software, are deferred until go‑live (or acceptance, if applicable) of the software and recognized in the same manner as the subscription over the remaining term of the initial contract. Professional services that are not connected with the implementation of software are recognized on a time and material basis as incurred.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less to be cash equivalents.
Fair Value of Financial Instruments	Fair Value of Financial Instruments All of the Company’s financial instruments are carried at fair value or amounts approximating fair value. Cash and cash equivalents, securities owned and securities sold, not yet purchased and certain payables are carried at market value or fair value.
Securities Transactions	Securities Transactions Receivables from brokers, dealers and clearing organizations include amounts receivable for fails to deliver, cash deposits for securities borrowed, the net amounts receivable on open transactions from clearing organizations and non-U.S. broker-dealers and billed amounts for commissions and fees and balance transfers on client commission arrangements, net of an allowance for doubtful accounts. Payables to brokers, dealers and clearing organizations include amounts payable for fails to receive, securities loaned and execution cost payables. Receivables from customers consist of fails to deliver, the net amounts receivable on open transactions from non-U.S. customers, as well as billed amounts for commissions and fees, net of an allowance for doubtful accounts. Payables to customers primarily consist of fails to receive. Commissions and fees and related expenses for all securities transactions are recorded on a trade date basis. Securities owned, at fair value consist of common stock and mutual funds. Securities sold, not yet purchased, at fair value consist of common stock. Marketable securities owned are valued using market quotes from third parties. Unrealized gains and losses are included in other revenues in the Consolidated Statements of Operations.
Securities Borrowed and Loaned	Securities Borrowed and Loaned Securities borrowed and securities loaned transactions are reported as collateralized financings. Securities borrowed transactions require the Company to deposit cash, letters of credit, or other collateral with the lender. With respect to securities loaned, the Company receives collateral in the form of cash or other collateral in amounts generally in excess of the fair value of securities loaned. The Company monitors the fair value of securities borrowed and loaned on a daily basis, with additional collateral obtained or refunded as necessary. Securities borrowed and securities loaned transactions are recorded at the amount of cash collateral advanced or received, adjusted for additional collateral advanced or received. The Company currently engages in securities borrowed and securities loaned transactions solely as part of its clearing process primarily to facilitate customer transactions, including for shortened or extended settlement activities and for failed settlements. On these transactions, interest income for securities borrowed is recorded in other revenue while interest expense from securities loaned is recorded in transaction processing expense on the Consolidated Statements of Operations.
Client Commission Arrangements	Client Commission Arrangements Institutional customers are permitted to allocate a portion of their gross commissions to pay for research products and other services provided by third parties and the Company’s subsidiaries. The amounts allocated for those purposes are commonly referred to as client commission arrangements. The cost of independent research and directed brokerage arrangements is accounted for on an accrual basis. Commission revenue is recorded when earned on a trade date basis. Payments relating to client commission arrangements are netted against the commission revenues. Research receivable, including prepaid research on behalf of customers and balance transfers due from other broker‑dealers, net of an allowance is included in receivables from customers and receivables from brokers, dealers and clearing organizations, while accrued research payable is included in accounts payable and accrued expenses in the Consolidated Statements of Financial Condition. Client commissions allocated for research and related research receivable and accrued research payable balances for the years ended December 31, 2017, 2016 and 2015 were as follows (dollars in millions): 2017 2016 2015 Client commissions allocated for research $ 96.3 $ 100.7 $ 110.9 Research receivable, gross $ 5.3 $ 3.0 $ 3.5 Allowance for research receivable (0.1) (0.1) (0.1) Research receivable, net of allowance $ 5.2 $ 2.9 $ 3.4 Accrued research payable $ 51.3 $ 45.8 $ 46.3
Capitalized Software	Capitalized Software Software development costs are capitalized when the technological feasibility of a product has been established. Technological feasibility is established when all planning, designing, coding and testing activities have been devised to ensure that the product can be produced to meet its design specifications, including functions, features, and technical performance requirements. All costs incurred to establish technological feasibility are expensed as incurred. Capitalized software costs are amortized using the straight‑line method over a three‑year period beginning when the product is available for general release to customers.
Research and Development	Research and Development All research and development costs are expensed as incurred. Research and development costs, which are primarily included in other general and administrative expenses and compensation and employee benefits in the Consolidated Statements of Operations, were approximately $32.8 million, $31.8 million and $29.2 million, excluding routine maintenance, for the years ended December 31, 2017, 2016 and 2015, respectively.
Business Combinations, Goodwill and Other Intangibles	Business Combinations, Goodwill and Other Intangibles Assets acquired and liabilities assumed are recorded at their fair values on the date of acquisition. The cost to be allocated in a business combination includes consideration paid to the sellers, including cash and the fair values of assets distributed and the fair values of liabilities assumed. Both direct (e.g., legal and professional fees) and indirect costs of the business combination are expensed as incurred. Certain agreements to acquire entities include potential additional consideration that is payable, contingent on the acquired company maintaining or achieving specified earnings levels in future periods. The fair value of any contingent consideration is recognized on the acquisition date with subsequent changes in that fair value reflected in the results of operations. The consolidated financial statements and results of operations reflect an acquired business from the date of acquisition. An intangible asset is recognized as an asset apart from goodwill if it arises from contractual or other legal rights or if it is separable (i.e., capable of being separated or divided from the acquired entity and sold, transferred, licensed, rented, or exchanged). Goodwill represents the excess of the cost of each acquired entity over the amounts assigned to the tangible and identifiable intangible assets acquired and liabilities assumed. The judgments that are made in determining the estimated fair value assigned to each class of assets acquired and liabilities assumed, as well as asset lives, can materially impact net income in periods following a business combination. Traditional approaches used to determine fair value include the income, cost and market approaches. The income approach presumes that the value of an asset can be estimated by the net economic benefit to be received over the life of the asset, discounted to present value. The cost approach presumes that an investor would pay no more for an asset than its replacement or reproduction cost. The market approach estimates value based on what other participants in the market have paid for reasonably similar assets. Although each valuation approach is considered in valuing the assets acquired, the approach or combination of approaches ultimately selected is based on the characteristics of the asset and the availability of information. Any goodwill is assessed no less than annually for impairment. The guidance for goodwill impairment testing allows an entity to assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount or to proceed directly to performing the two-step impairment test. The fair values used in the Company’s two-step impairment testing are determined by the discounted cash flow method (an income approach) and where appropriate, a combination of the discounted cash flow method and the guideline company method (a market approach). An impairment loss is indicated if the estimated fair value of a reporting unit is less than its net book value. In such a case, the impairment loss is calculated as the amount by which the carrying value of goodwill exceeds its implied fair value. In determining the fair value of each of the Company’s reporting units, the discounted cash flow analyses employed require significant assumptions and estimates about the future operations of each reporting unit. Significant judgments inherent in these analyses include the determination of appropriate discount rates, the amount and timing of expected future cash flows and growth rates. The cash flows employed in the Company’s discounted cash flow analyses are based on financial budgets and forecasts developed internally by management. The Company’s discount rate assumptions are based on a determination of its required rate of return on equity capital. Other intangibles with definite lives are amortized over their useful lives. All other intangibles are assessed at least annually for impairment. If impairment is indicated, an impairment loss is calculated as the amount by which the carrying value of an intangible asset exceeds its estimated fair value.
Premises and Equipment	Premises and Equipment Furniture, fixtures and equipment are carried at cost and are depreciated using the straight‑line method over the estimated useful lives of the assets (generally three to seven years). Leasehold improvements are carried at cost and are amortized using the straight‑line method over the lesser of the estimated useful lives of the related assets or the non‑cancelable lease term.
Impairment of Long-Lived Assets	Impairment of Long‑Lived Assets Long‑lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Determination of recoverability is generally based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition, as well as specific appraisal in certain instances. Measurement of an impairment loss for long‑lived assets that management expects to hold and use is based on the fair value of the asset as estimated using a cash flow model. Long‑lived assets to be disposed of are reported at the lower of carrying amount or fair value less costs to sell.
Contingencies and Uncertainties	Contingencies and Uncertainties The Company may be subject to losses that arise from litigation, mediation, arbitration, regulatory proceedings and various contingencies and uncertainties. Liabilities are recognized when a loss is probable and can be reasonably estimated.
Income Taxes	Income Taxes Income taxes are accounted for using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. 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 recorded against deferred tax assets if it is more likely than not that such assets will not be realized. An uncertain tax position is recognized based on the determination of whether or not a tax position is more likely than not to be sustained upon examination based upon the technical merits of the position. If this recognition threshold is met, the tax benefit is then measured based on the largest benefit that has a greater than fifty percent likelihood of being realized upon ultimate resolution.
Taxes Collected from Customers and Remitted to Governmental Authorities	Taxes Collected from Customers and Remitted to Governmental Authorities Taxes assessed by a governmental authority that are directly imposed on a revenue producing transaction between the Company and its customers, including but not limited to sales, use, value added and some excise taxes are presented in the consolidated financial statements on a net basis (excluded from revenues).
Earnings per Share	Earnings per Share Basic earnings per share is determined by dividing earnings by the average number of shares of common stock outstanding, while diluted earnings per share is determined by dividing earnings by the average number of shares of common stock adjusted for the dilutive effect of common stock equivalents by application of the treasury stock method. Common stock equivalents are excluded from the diluted calculation if their effect is anti-dilutive.
Share-based Compensation	Share‑based Compensation Share‑based compensation expense requires measurement of compensation cost for share‑based awards at fair value and recognition of compensation cost over the vesting period. For awards with graded vesting schedules that only have service conditions, the Company recognizes compensation cost evenly over the requisite service period for the entire award using the straight‑line attribution method. For awards with service conditions as well as performance or market conditions, the Company recognizes compensation cost on a straight‑line basis over the requisite service period for each separately vesting portion of the award as if the award was, in‑substance, multiple awards. The fair value of stock options granted is estimated using the Black‑Scholes option‑pricing model, which considers, among other factors, the expected term of the award and the expected volatility of the Company’s stock price. Although the Black‑Scholes model meets the requirements of ASC 718, Compensation—Stock Compensation , the fair values generated by the model may not be indicative of the actual fair values of the underlying awards, as it does not consider other factors important to those share‑based compensation awards, such as continued employment, periodic vesting requirements and limited transferability. The risk-free interest rate used in the Black-Scholes option-pricing model is based on the U.S. Treasury yield curve in effect at the time of grant. The expected option life is based on historical experience of employee exercise behavior. Expected volatility is based on historical volatility, implied volatility, price observations taken at regular intervals and other factors deemed appropriate. Expected dividend is based upon the current dividend rate. The fair value of restricted stock unit awards is based on the fair value of the Company’s common stock on the grant date. Certain restricted stock unit awards granted have both service and market conditions. Awards with market conditions are valued based on (a) the grant date fair value of the award for equity-based awards or (b) the period-end fair value for liability-based awards. Grant date fair value for market condition based awards is determined using a Monte Carlo simulation model to simulate a range of possible future stock prices for the Company’s common stock. Compensation costs for awards with market conditions are recognized for each separately vesting portion of the award over the estimated service period calculated by the Monte Carlo simulation model. For restricted stock unit awards with a performance condition, fair value is estimated throughout the life of the award based on the probability of achieving the performance condition. Excess tax benefits (which represent the excess of actual tax benefits received at the date of vesting or settlement over the benefits recognized over the vesting period or upon issuance of share-based payments) and tax deficiencies (which represent the amount by which actual tax benefits received at the date of vesting or settlement is lower than the benefits recognized over the vesting period or upon issuance of share-based payments) are recorded in the income statement as an increase or decrease in income taxes when the awards vest or are settled. Cash flows related to income tax deductions, if any, in excess of the compensation cost recognized on share‑based awards exercised or vested during the period presented (excess tax benefit) were classified in financing cash flows in the Consolidated Statements of Cash Flows through December 31, 2016. As of January 1, 2017, due to the adoption of Accounting Standards Update (“ASU”) 2016-09, Improvements to Employee Share-Based Payment Accounting , excess tax benefits, along with other income tax cash flows, are recorded as an operating activity in the statement of cash flows rather than, as previously required, a financing activity. For more information on the impact of this standard to the consolidated financial statements, see “ Recently Adopted Accounting Standards” below. Phantom stock awards are settled in cash and are therefore classified as liability awards. The fair value of the liability is remeasured at each reporting date until final settlement using the fair value of the Company’s common stock on that date. At December 31, 2017, the Company did not have any phantom awards outstanding, as the Company discontinued granting phantom share awards effective January 1, 2015 and the last awards outstanding vested on February 22, 2016.
Foreign Currency Translation	Foreign Currency Translation Assets and liabilities denominated in non-U.S. currencies are translated at rates of exchange prevailing on the date of the Consolidated Statements of Financial Condition, and revenues and expenses are translated at average rates of exchange during the fiscal year. Gains or losses on translation of the financial statements of a foreign operation, where the functional currency is other than the U.S. Dollar, together with the after-tax effect of exchange rate changes on intercompany transactions of a long-term investment nature, are reflected as a component of accumulated other comprehensive income in stockholders’ equity. Gains or losses on foreign currency transactions are included in other general and administrative expenses in the Consolidated Statements of Operations.
Common Stock Held in Treasury, at cost	Common Stock Held in Treasury, at Cost The purchase of treasury stock is accounted for under the cost method with the shares of stock repurchased reflected as a reduction to stockholders’ equity and included in common stock held in treasury, at cost, in the Consolidated Statements of Financial Condition. When treasury shares are reissued, they are recorded at the average cost of the treasury shares acquired. The Company held 20.0 million and 19.8 million shares of common stock in treasury as of December 31, 2017 and 2016, respectively.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update 2014‑09, Revenue from Contracts with Customers . This standard created ASC 606, providing companies with a single five step revenue recognition model for use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry‑specific revenue guidance. The core principle of the model is to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. It also requires significant additional qualitative and quantitative disclosures describing the nature, amount, timing, and uncertainty of revenues and cash flows arising from contracts with customers, along with detailed information regarding the nature of the Company’s performance obligations and contracts and the timing of recognition and payment, among other items. ASC 606 is effective for annual and interim reporting periods beginning after December 15, 2017. On January 1, 2018, the Company adopted ASC 606, using the modified retrospective transition method applied to all contracts as of January 1, 2018. The Company has identified two key accounting changes that will affect the timing of revenue recognition upon adoption relating to bundled commission arrangements and fees for licenses of functional intellectual property. The financial impact of these accounting changes includes (1) a deferral of revenues primarily generated in the first half of the year for commissions attributable to analytics products under bundled arrangements that will be recognized over the course of the year as the performance obligations for those analytics products are satisfied and (2) an acceleration of license fee revenues to the delivery date for software provided for a specified period. These changes only relate to the timing of when revenue is recognized and have no effect on the underlying transaction price of the products and services the Company performs. Upon adoption, the Company recorded a net cumulative-effect decrease to opening retained earnings of approximately $ 0.04 million as of January 1, 2018, which is primarily related to: (i) the deferral of commissions allocated to analytics products in bundled commission arrangements where the analytics services have not yet been transferred to the customer as of December 31, 2017 but whose commissions were appropriately recognized in the previous year under the superseded revenue recognition guidance, and (ii) the acceleration of revenue for certain product license fees associated with the licenses of functional intellectual property recognized at the point in time the customer is able to use and benefit from the license instead of being appropriately recognized over the license period under the superseded revenue recognition guidance. In May 2017, the FASB issued ASU 2017-09, Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting . The amendments in this ASU clarify which changes to the terms or conditions of a share-based payment award must be accounted for as modifications. The new guidance allows entities to make non-substantive changes to awards without accounting for them as modifications, which results in fewer changes to the terms of an award being accounted for as modifications and reduces diversity in practice when applying modification accounting. ASU 2017-09 is effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods. This new guidance was adopted on January 1, 2018 and did not have a material effect on the Company’s financial statements. In November 2016, the FASB issued ASU 2016‑18, Statement of Cash Flows (Topic 230): Restricted Cash. The amendments in this ASU require that the statement of cash flows explain the change during the period in the total of cash, cash equivalents and restricted cash. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016‑18 is effective for annual reporting periods beginning after December 15, 2017, including interim periods within those fiscal years, with early adoption permitted. This new guidance was adopted on January 1, 2018 and did not have a material effect on the Company’s financial statements. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments . The amendments in this ASU provide specific guidance for eight specific cash flow classification issues, with the objective of reducing the existing diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows under Topic 230, Statement of Cash Flows . These amendments are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years, with early adoption permitted. This new guidance was adopted on January 1, 2018 and had no impact on the Company’s financial statements. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, which changes the accounting for certain aspects of share-based payments to employees. The new guidance requires, among its other provisions, that excess tax benefits (which represent the excess of actual tax benefits received at the date of vesting or settlement over the benefits recognized over the vesting period or upon issuance of share-based payments) and tax deficiencies (which represent the amount by which actual tax benefits received at the date of vesting or settlement is lower than the benefits recognized over the vesting period or upon issuance of share-based payments) be recorded in the statement of operations as an increase or decrease in income tax expense (benefit) when the awards vest or are settled. This is in contrast to the prior requirement that these excess tax benefits be recognized in additional paid-in capital and these tax deficiencies be recognized either as an offset to accumulated excess tax benefits, if any, or in the statement of operations. The new guidance also requires excess tax benefits to be classified along with other income tax cash flows as an operating activity in the statement of cash flows rather than, as previously required, a financing activity. The new guidance is effective for annual and interim reporting periods beginning after December 15, 2016 and as such was implemented on January 1, 2017. As a result of this adoption, the Company: · Recognized net excess tax benefits of $1.3 million during the year ended December 31, 2017, which is included in income tax benefit in the Consolidated Statements of Operations. · Elected to adopt the cash flow presentation of the excess tax benefits prospectively during the year ended December 31, 2017, where these benefits are classified along with other income tax cash flows as an operating activity in the Consolidated Statements of Cash Flows. · Elected to account for forfeitures as they occur rather than under the previous method of estimating the number of stock-based awards expected to vest in order to determine the amount of compensation cost to be recognized in each period. This resulted in an adjustment for the cumulative effect of this accounting change as of January 1, 2017 to reduce retained earnings by $0.6 million and to increase deferred tax assets and additional paid-in capital by $0.3 million and $0.9 million, respectively. · Did not change its policy on statutory withholding requirements. Amounts paid by the Company to taxing authorities when directly withholding shares associated with employees’ income tax withholding obligations are classified as a financing activity in the Consolidated Statements of Cash Flows. · Excluded the excess tax benefits from the assumed proceeds available to repurchase shares in the computation of diluted earnings per share for the year ended December 31, 2017. In April 2015, the FASB issued ASU 2015-03, Simplifying the Presentation of Debt Issuance Costs , which changes the presentation of debt issuance costs in financial statements. ASU 2015-03 requires an entity to present such costs in the balance sheet as a direct deduction from the related debt liability rather than as an asset. Amortization of the costs will continue to be reported as interest expense. The new standard was adopted on January 1, 2016 and did not have a material effect on the Company’s financial statements.

Summary of Significant Accoun34

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of client commission arrangement	Client commissions allocated for research and related research receivable and accrued research payable balances for the years ended December 31, 2017, 2016 and 2015 were as follows (dollars in millions): 2017 2016 2015 Client commissions allocated for research $ 96.3 $ 100.7 $ 110.9 Research receivable, gross $ 5.3 $ 3.0 $ 3.5 Allowance for research receivable (0.1) (0.1) (0.1) Research receivable, net of allowance $ 5.2 $ 2.9 $ 3.4 Accrued research payable $ 51.3 $ 45.8 $ 46.3

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Measurements
Fair value measurements for assets and liabilities measured on a recurring basis	Fair value measurements for those items measured on a recurring basis are as follows (dollars in thousands): December 31, 2017 Total Level 1 Level 2 Level 3 Assets Securities owned, at fair value: Corporate stocks - trading securities $ 78 $ 78 $ — $ — Mutual funds 1,481 1,481 — — Total $ 1,559 $ 1,559 $ — $ — Liabilities Securities sold, not yet purchased, at fair value: Corporate stocks - trading securities 1 1 — — Total $ 1 $ 1 $ — $ — December 31, 2016 Total Level 1 Level 2 Level 3 Assets Securities owned, at fair value: Corporate stocks - trading securities $ 244 $ 244 $ — $ — Mutual funds 2,313 2,313 — — Total $ 2,557 $ 2,557 $ — $ — Liabilities Securities sold, not yet purchased, at fair value: Corporate stocks - trading securities 249 249 — — Total $ 249 $ 249 $ — $ —

Divestitures and Acquisitions (

Divestitures and Acquisitions (Tables) - Sale of subsidiaries	12 Months Ended
	Dec. 31, 2017
ITG Investment Research
Acquisitions
Summary of components of pre-tax gain	The following table summarizes the components of the pre-tax gain (dollars in thousands): Cash proceeds from sale $ 12,000 Carrying value of net assets disposed (7,502) Direct selling costs (4,477) Pre-tax gain on sale $ 21
Energy research business
Acquisitions
Summary of components of pre-tax gain	The following table summarizes the components of the pre-tax gain (dollars in thousands): Cash proceeds from sale $ 120,500 Working capital adjustment (1,615) Carrying value of net assets disposed (3,025) Direct selling costs (8,161) Pre-tax gain on sale $ 107,699

Restructuring Charges (Tables)

Restructuring Charges (Tables)	12 Months Ended
	Dec. 31, 2017
Restructuring Plan 2016
Restructuring Charges.
Summary of activity and liability balances	Activity and liability balances recorded as part of the restructuring plan through December 31, 2017 are as follows (dollars in thousands): Amount Balance at December 31, 2016 $ 3,157 Utilized—cash (primarily severance related) (3,119) Accrual adjustment (58) Currency translation 26 Balance at December 31, 2017 $ 6

Goodwill and Other Intangibles

Goodwill and Other Intangibles (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Other Intangibles
Changes in the carrying amount of goodwill by reportable segment	The following table presents the changes in the carrying amount of goodwill held entirely within the Company’s European Operations segment for the year ended December 31, 2017 (dollars in thousands): Total Balance at December 31, 2015 $ 11,933 Currency translation adjustment (1,831) Balance at December 31, 2016 $ 10,102 Currency translation adjustment 952 Balance at December 31, 2017 $ 11,054
Summary of acquired other intangible assets	Acquired other intangible assets consisted of the following at December 31, 2017 and 2016 (dollars in thousands): December 31, 2017 December 31, 2016 Gross Carrying Accumulated Gross Carrying Accumulated Useful Lives Amount Amortization Amount Amortization (Years) Trade name $ 8,529 $ — $ 8,518 $ — — Customer-related intangibles 10,217 6,219 10,358 5,584 16.9 Proprietary software 23,321 22,197 23,165 21,456 8.4 Trading rights 339 — 339 — — Other 50 — 50 — — Total $ 42,456 $ 28,416 $ 42,430 $ 27,040
Schedule of future amortization expense for acquired other intangibles	The Company’s estimate of future amortization expense for acquired other intangibles that exist at December 31, 2017 and 2016 is as follows (dollars in thousands): Estimated Year Amortization 2018 $ 1,017 2019 865 2020 653 2021 571 2022 571 Thereafter 1,447 Total $ 5,124
Schedule of changes in the carrying amount of net intangible assets	The following table represents the changes in the carrying amount of net intangible assets for the years ended December 31, 2017 and 2016 (dollars in thousands): Total Balance at December 31, 2015 $ 24,611 Amortization (1,852) Divestiture of energy research operations (6,684) Currency translation adjustment (685) Balance at December 31, 2016 $ 15,390 Amortization (1,276) Impairment charge (325) Currency translation adjustment 251 Balance at December 31, 2017 $ 14,040

Securities Owned and Sold, No39

Securities Owned and Sold, Not Yet Purchased (Tables)	12 Months Ended
	Dec. 31, 2017
Securities Owned and Sold, Not Yet Purchased
Summary of securities owned and securities sold, not yet purchased	The following is a summary of securities owned and securities sold, not yet purchased (dollars in thousands): Securities Sold, Not Yet Securities Owned Purchased December 31, December 31, December 31, December 31, 2017 2016 2017 2016 Corporate stocks - trading securities $ 78 $ 244 $ 1 $ 249 Mutual funds 1,481 2,313 — — Total $ 1,559 $ 2,557 $ 1 $ 249

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Taxes
Schedule of components of income tax expense (benefit)	Income tax expense (benefit) consisted of the following components (dollars in thousands): 2017 2016 2015 Current: Federal $ (423) $ (9,918) $ 5,731 State 1,072 (624) (1,645) Foreign 11,490 8,975 12,647 12,139 (1,567) 16,733 Deferred: Federal 25,797 (12,687) 13,665 State 7,694 (2,217) 2,570 Foreign 335 (851) (3,312) 33,826 (15,755) 12,923 Total $ 45,965 $ (17,322) $ 29,656
Summary of income before income taxes	Income (loss) before income taxes consisted of the following (dollars in thousands): 2017 2016 2015 U.S. $ (56,465) $ (81,579) $ 51,797 Foreign 62,990 38,339 69,429 Total $ 6,525 $ (43,240) $ 121,226
Components of deferred income tax assets and liabilities	The components of the Company’s net deferred tax asset are as follows (dollars in thousands): 2017 2016 Deferred tax assets: Compensation and benefits $ 5,912 $ 9,715 Net operating loss and capital loss carryover 18,974 19,755 Share-based compensation 5,092 6,824 Research and development credits 7,438 7,550 Foreign tax credits 11,117 12,660 Tax benefits on uncertain tax positions 831 1,351 Goodwill and other intangibles 6,363 8,015 Depreciation 3,527 1,167 Capitalized software 383 — Rent 3,013 3,695 Other 700 1,564 Total deferred tax assets 63,350 72,296 Less: valuation allowance (58,448) (20,979) Total deferred tax assets, net of valuation allowance 4,902 51,317 Deferred tax liabilities: Capitalized software — (12,174) Indefinite life intangible (1,695) — Other (55) (455) Total deferred tax liabilities (1,750) (12,629) Net deferred tax assets $ 3,152 $ 38,688
Summary of net operating loss carry forwards and respective expiration period	Net operating loss carryforwards expire as follows (dollars in thousands): Amount Years remaining Hong Kong and Australia $ 76,375 Indefinite State and local (United States) 36,111 13 - 20 years $ 112,486
Reconciliation of the U.S. federal statutory income tax rate and actual effective tax rate on earnings	2017 2016 2015 U.S. federal statutory income tax rate 35.0 % 35.0 % 35.0 % State and local income taxes, net of U.S. federal income tax effect 0.6 5.2 0.4 Foreign tax impact, net (81.8) 6.2 (7.2) Deemed dividend on changes to internal capital structure outside North America (1) — — 5.4 Valuation allowance 585.8 — — Tax impact of Tax Cuts and Jobs Act 149.2 — — Stock windfall/shortfall (13.5) — — Impact of deductible basis on the sale of energy research business — — (14.8) Reserves released upon tax settlement — 18.6 — Non-deductible costs (2) 21.3 (22.8) 6.1 Other, net 7.9 (2.1) (0.4) Effective income tax rate 704.5 % 40.1 % 24.5 % (1) Reflects the impact of the tax on a deemed dividend from changes to the internal capital structure of the Company's operations outside of North America. (2) Includes the impact of the non-deductible payments in 2015 and charges accrued in 2016 payable to the Securities and Exchange Commission (the “SEC”) (see Note 21, Commitments and Contingencies ). Additionally, 2017 and 2016 includes non-deductible officer’s compensation.
Reconciliation of the beginning and ending balances of unrecognized tax benefits	A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows (dollars in thousands): Uncertain Tax Benefits 2017 2016 2015 Balance, January 1 $ 7,356 $ 15,553 $ 14,395 Additions based on tax positions related to the current year 591 66 2,807 Additions based on tax positions of prior years 4 406 349 Reductions for tax positions of prior years (13) — (36) Reductions due to settlements with taxing authorities (64) (2,153) (1,773) Reductions due to expiration of statute of limitations (181) (6,516) (189) Balance, December 31 $ 7,693 $ 7,356 $ 15,553

Receivables and Payables (Table

Receivables and Payables (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables and Payables
Summary of receivables from and payables to, brokers, dealers and clearing organizations	The following is a summary of receivables from, and payables to, brokers, dealers and clearing organizations at December 31 (dollars in thousands): Receivables from Payables to December 31, December 31, December 31, December 31, 2017 2016 2017 2016 Broker-dealers $ 189,817 $ 147,116 $ 105,022 $ 56,894 Clearing organizations 708 5,117 10,011 8,096 Securities borrowed 4,246 374 — — Securities loaned — — 4,245 35,198 Allowance for doubtful accounts (864) (313) — — Total $ 193,907 $ 152,294 $ 119,278 $ 100,188
Summary of receivables from and payables to customers	The following is a summary of receivables from, and payables to, customers at December 31 (dollars in thousands): Receivables from Payables to December 31, December 31, December 31, December 31, 2017 2016 2017 2016 Customers $ 75,062 $ 55,006 $ 23,568 $ 12,272 Allowance for doubtful accounts (367) (520) — — Net $ 74,695 $ 54,486 $ 23,568 $ 12,272
Schedule of interest earned and interest incurred on securities borrowed and loaned	the resulting net amount included in other revenue on the Consolidated Statements of Operations for 2016 and 2015 were as follows (dollars in thousands): 2016 2015 Interest earned $ 1,961 $ 5,512 Interest incurred (1,132) (3,720) Net $ 829 $ 1,792
Summary of the transactions under certain Master Securities Lending Agreements that may be eligible for offsetting if an event of default occurred and a right of offset was legally enforceable	The following table summarizes the transactions under certain Master Securities Lending Agreements that may be eligible for offsetting if an event of default occurred and a right of offset was legally enforceable (dollars in thousands): Gross Amounts Net Amounts Collateral Offset in the Presented in the Received or Gross Amounts of Consolidated Consolidated Pledged Recognized Assets/ Statement of Statement of (including Net (Liabilities) Financial Condition Financial Condition Cash) Amount As of December 31, 2017: Deposits paid for securities borrowed $ 4,246 $ — $ 4,246 $ 4,246 $ — Deposits received for securities loaned (4,245) — (4,245) (4,229) (16) As of December 31, 2016: Deposits paid for securities borrowed $ 374 $ — $ 374 $ 374 $ — Deposits received for securities loaned (35,198) — (35,198) (34,245) (953)

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Premises and Equipment
Schedule of premises and equipment	The following is a summary of premises and equipment at December 31 (dollars in thousands): 2017 2016 Furniture, fixtures and equipment $ 149,366 $ 157,770 Leasehold improvements 45,543 52,440 194,909 210,210 Less: accumulated depreciation and amortization 140,949 150,877 Total $ 53,960 $ 59,333

Capitalized Software (Tables)

Capitalized Software (Tables)	12 Months Ended
	Dec. 31, 2017
Capitalized Software
Schedule of capitalized software costs	The following is a summary of capitalized software costs at December 31 (dollars in thousands): 2017 2016 Capitalized software costs $ 86,316 $ 82,877 Less: accumulated amortization 45,057 44,271 Total $ 41,259 $ 38,606

Accounts Payable and Accrued 44

Accounts Payable and Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2017
Accounts Payable and Accrued Expenses
Summary of accounts payable and accrued expenses	The following is a summary of accounts payable and accrued expenses at December 31 (dollars in thousands): December 31, December 31, 2017 2016 Accrued research payables $ 51,275 $ 45,826 Accrued compensation and benefits 37,911 34,526 Accrued settlement costs — 24,450 Accrued rent 14,821 19,061 Trade payables 20,820 14,474 Deferred revenue 8,057 7,643 Deferred compensation 2,525 3,262 Accrued restructuring 6 3,157 Accrued transaction processing 3,257 3,230 Other 27,823 18,714 Total $ 166,495 $ 174,343

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Borrowings
Summary of term debt	At December 31, term debt is comprised of the following (dollars in thousands): December 31, December 31, 2017 2016 Term loans $ 3,104 $ 3,098 Obligations under capital lease — 3,269 Total $ 3,104 $ 6,367
Summary of remaining scheduled principal repayments	The reductions to the principal balance applying the interest method to the required payments are as follows (dollars in thousands): Aggregate Year Amount 2018 $ 715 2019 737 2020 759 2021 193 $ 2,404

Accumulated Other Comprehensi46

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income
Schedule of components and allocated tax effects of accumulated other comprehensive income	The components and allocated tax effects of other comprehensive income for the periods ended December 31, 2017 and December 31, 2016 are as follows (dollars in thousands): Year Ended December 31, 2017 Balance at December 31, 2016 $ (33,977) Other comprehensive income 12,580 Balance at December 31, 2017 $ (21,397) Year Ended December 31, 2016 Balance at December 31, 2015 $ (19,495) Other comprehensive loss before reclassifications (13,416) Amounts reclassified from accumulated other comprehensive loss (1) (1,066) Net current-period other comprehensive loss (14,482) Balance at December 31, 2016 $ (33,977) (1) In the third quarter of 2016, the Company substantially completed the liquidation of its investment in its Israel entity that ceased operations in December 2013. During the Company’s period of ownership and through December 2013, the Company had $1.1 million in accumulated foreign exchange translation gains as a component of equity, which have been reclassified during the year ended December 31, 2016 as a gain that reduced other general and administrative expenses in the Consolidated Statement of Operations.

Net Capital Requirement (Tables

Net Capital Requirement (Tables)	12 Months Ended
	Dec. 31, 2017
Net Capital Requirement
Net capital balances and the amounts in excess of required net capital for the U.S. Operations	Net capital balances and the amounts in excess of required net capital at December 31, 2017 for the U.S. Operations are as follows (dollars in thousands): Net Capital Excess U.S. Operations ITG Inc. $ 86,165 $ 85,165 AlterNet 4,300 4,200 ITG Derivatives 579 479
Net capital balances and the amounts in excess of required net capital for other than U.S. Operations	The regulatory net capital balances and amount of regulatory capital in excess of the minimum requirements applicable to each business at December 31, 2017, is summarized in the following table (dollars in thousands): Net Capital Excess Canadian Operations Canada $ 24,450 $ 24,050 European Operations Ireland 46,030 12,278 U.K. 2,036 1,025 Asia Pacific Operations Australia 27,008 17,591 Hong Kong 5,993 5,538 Singapore 1,121 1,047

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity
Summary of share repurchases	The table below summarizes the Company’s share repurchases beginning January 1, 2015 under its Board of Directors’ authorizations: Amount Shares Authorized Total Remaining Shares Repurchased by Board Shares Under Board Under Board Expiration (Shares in Repurchased Authorization Authorization Repurchase Program Authorization Date Date millions) (millions) (millions) 2017 2016 2015 May 2013 none 4.0 4.0 — — — 0.8 October 2014 none 4.0 3.4 0.6 0.9 1.3 1.2 Total shares repurchased under authorization 0.9 1.3 2.0 Cost (millions) $ 16.9 $ 22.1 $ 42.0 Average share price $ 19.13 $ 16.55 $ 21.10

Employee and Non-Employee Dir49

Employee and Non-Employee Director Stock and Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Employee and Non-Employee Director Stock and Benefit Plans
Schedule of changes in stock options	Weighted Options Number of Average Outstanding Shares Exercise Price Outstanding at December 31, 2014 306,853 $ 17.23 Granted — — Exercised (71,455) 16.26 Forfeited (192,733) 18.71 Outstanding at December 31, 2015 42,665 $ 12.17 Granted 196,851 16.18 Exercised (42,665) 12.17 Forfeited — — Outstanding at December 31, 2016 196,851 $ 16.18 Granted — — Exercised — — Forfeited — — Outstanding at December 31, 2017 196,851 $ 16.18 Amount exercisable at December 31, 2017 65,630 $ 16.18 2016 — $ — 2015 42,665 $ 12.17
Schedule of stock options outstanding and exercisable by exercise price	Options Outstanding Options Exercisable Weighted Average Weighted Weighted Remaining Average Average Number Contractual Exercise Number Exercise Exercise Price Outstanding Life (Years) Price Exercisable Price $ 16.18 196,851 6.04 $ 16.18 65,630 $ 16.18
Schedule of information about stock options	($ in thousands) 2017 2016 2015 Total intrinsic value of stock options exercised $ — $ 220 $ 370 Weighted average grant date fair value of stock options granted during period, per share — 16.18 — Cash received from stock option exercises $ — $ 208 $ 298
Schedule of status of restricted share awards	Number of Shares Underlying ROE-Based, Number of Market-Based or Shares Weighted Performance- underlying Time- Average Based Restricted Based Restricted Total Number of Grant Date Stock Units Stock Units Shares Fair Value Outstanding at December 31, 2014 438,022 2,221,206 2,659,228 $ 13.51 Granted 263,766 1,932,425 2,196,191 18.79 Vested (97,112) (1,061,935) (1,159,047) 13.49 Forfeited (227,201) (298,135) (525,336) 16.10 Outstanding at December 31, 2015 377,475 2,793,561 3,171,036 $ 16.75 Granted 228,895 1,437,021 1,665,916 16.16 Vested (73,243) (968,995) (1,042,238) 16.06 Forfeited (190,757) (540,693) (731,450) 16.88 Outstanding at December 31, 2016 342,370 2,720,894 3,063,264 $ 16.63 Granted 140,796 1,118,596 1,259,392 19.81 Vested (51,498) (1,279,523) (1,331,021) 16.60 Forfeited (38,324) (45,766) (84,090) 18.99 Outstanding at December 31, 2017 393,344 2,514,201 2,907,545 $ 18.10
Schedule of status of phantom share awards	Weighted Average Number of Grant Date Shares Fair Value Outstanding at December 31, 2014 358,349 $ 11.61 Granted — — Vested (257,279) 11.58 Forfeited (43,272) 10.99 Outstanding at December 31, 2015 57,798 $ 12.24 Granted — — Vested (57,798) 12.24 Forfeited — — Outstanding at December 31, 2016 — $ —

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share
Reconciliation of the basic and diluted earnings per share computations	The following is a reconciliation of the basic and diluted earnings per share computations (dollars in thousands, except per share amounts): December 31, 2017 2016 2015 Net (loss) income for basic and diluted (loss) income per share $ (39,440) $ (25,918) $ 91,570 Shares of common stock and common stock equivalents: Average common shares used in basic computation 33,009 32,906 33,907 Effect of dilutive securities — — 908 Average common shares used in diluted computation 33,009 32,906 34,815 (Loss) income per share: Basic $ (1.19) $ (0.79) $ 2.70 Diluted $ (1.19) $ (0.79) $ 2.63

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Contingencies - Legal Matters
Schedule of minimum future rental commitments under non-cancelable operating leases	Minimum future rental commitments under non‑cancelable operating leases follow (dollars in thousands): Aggregate Year Ending December 31, Amount 2018 $ 13,514 2019 13,542 2020 12,161 2021 11,559 2022 10,402 2023 and thereafter 60,301 Total $ 121,479

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting
Summary of the segment financial information	A summary of the segment financial information is as follows (dollars in thousands): U.S. Canadian European Asia Pacific Operations Operations Operations Operations Corporate Consolidated 2017 Total revenues $ 204,990 $ 63,294 $ 151,472 $ 62,218 $ 1,720 $ 483,694 (Loss) income before income tax (benefit) expense (1) (2) (24,473) 10,608 41,103 11,680 (32,393) 6,525 Identifiable assets 342,487 108,457 274,836 59,076 — 784,856 Capital purchases 13,278 1,183 3,289 1,652 — 19,402 Depreciation and amortization 33,307 2,420 6,094 1,994 1,338 45,153 Non-cash share-based compensation 9,543 2,390 5,267 959 2,079 20,238 2016 Total revenues $ 229,655 $ 61,822 $ 125,945 $ 47,919 $ 3,711 $ 469,052 (Loss) income before income tax expense (benefit) (3) (4) (5) (6) (7) (8) (11,133) 11,564 25,470 1,553 (70,694) (43,240) Identifiable assets 396,419 80,943 236,071 61,852 — 775,285 Capital purchases 15,547 2,549 1,886 1,333 — 21,315 Depreciation and amortization 32,896 2,402 6,741 1,484 — 43,523 Non-cash share-based compensation 10,642 2,383 5,948 925 5,722 25,620 2015 Total revenues $ 285,230 $ 63,028 $ 129,729 $ 48,179 $ 108,637 $ 634,803 Income before income tax expense (9) (10) (11) 16,000 10,643 28,244 1,620 64,719 121,226 Identifiable assets 1,304,995 76,561 262,095 65,371 — 1,709,022 Capital purchases 7,748 2,175 1,334 648 — 11,905 Depreciation and amortization 33,971 2,247 6,560 1,373 — 44,151 Non-cash share-based compensation 10,725 1,466 4,505 866 (895) 16,667 (1) In the fourth quarter of 2017, the Company incurred an $8.1 million charge for the write-off of fixed assets and other costs associated with the consolidation of ITG’s New York office space. (2) In the third quarter of 2017, the Company deemed the remaining value of a customer intangible asset recorded in ITG Derivatives of $0.3 million fully impaired and incurred legal fees related to the planned formation of the Matrix derivatives venture of $0.8 million. (3) In the second quarter of 2016, the Company received insurance proceeds of $2.4 million from its corporate insurance carrier to settle a claim for lost profits arising from an August 2015 outage in its outsourced primary data center in the U.S. Additionally, the Company generated a nominal gain on the completion of the sale of its investment research operations in May 2016. (4) In the second half of 2016, the Company incurred $24.5 million for a settlement with the SEC with respect to an inquiry involving pre-released ADRs and incurred legal and other related costs associated with this matter of $2.9 million. (5) During the second quarter of 2016, the Company incurred restructuring charges of $4.3 million related to (a) the reduction in its single stock sales trading and sales organizations and (b) the closing of its U.S. matched-book securities lending operations and its Canadian arbitrage trading desk. In the fourth quarter of 2016, the Company incurred additional restructuring charges of $5.3 million related to management delayering and the elimination of certain positions. (6) The Company’s current Chief Executive Officer was granted cash and stock awards upon the commencement of his employment in January 2016, a significant portion of which replaced awards he forfeited at his former employer. Due to U.S. tax regulations, only a small portion of the amount expensed for these awards was eligible for a tax deduction. (7) In the first half of 2016, the Company incurred a charge of $4.8 million, net of an insurance recovery of $0.5 million, to settle an arbitration case with its former CEO and incurred legal fees of $2.7 million. In the third quarter of 2016, the Company recorded a reimbursement of $0.9 million of these legal fees from its insurance carrier. (8) In the third quarter of 2016, the Company substantially completed the liquidation of its investment in its Israel entity that ceased operations in December 2013. During the Company’s period of ownership and through December 2013, the Company had accumulated foreign exchange translation gains as a component of equity, which have been reclassified as a gain that reduced other general and administrative expenses in the Consolidated Statement of Operations. (9) In December 2015, the Company completed the sale of the subsidiaries conducting its energy research operations to an affiliate of Warburg Pincus, a global private equity firm, for $120.5 million. The pre-tax gain of $107.7 million is net of a working capital adjustment on the closing balance sheet, direct costs related to the sale and the carrying value of the net assets disposed. (10) In the third quarter of 2015, the Company reached a final settlement with the SEC to pay an aggregate amount of $20.3 million in connection with the SEC’s investigation into a proprietary trading pilot operated during 2010 and 2011. During 2015, the Company incurred $4.9 million in legal and other related costs associated with this matter. (11) In December 2015, the Company completed changes to the internal capital structure of its holding company outside North America to provide continued flexibility for the movement of capital. This amendment accelerated the U.S. taxation of amounts earned outside of North America, resulting in a tax charge of $6.5 million.
Schedule of total revenues for the products and services provided by the company	The table below details the total revenues for the categories of products and services provided by the Company for the years ended December 31, 2017, 2016 and 2015 (dollars in thousands): December 31, 2017 2016 2015 Revenues: Execution Services $ 344,192 $ 328,252 $ 386,158 Workflow Technology 92,533 92,891 94,117 Analytics 45,249 44,198 45,891 Corporate (non-product) 1,720 3,711 108,637 Total Revenues $ 483,694 $ 469,052 $ 634,803
Schedule of long-lived assets, classified by the geographic region	Long‑lived assets, classified by the geographic region in which the Company operates, are as follows (dollars in thousands): 2017 2016 2015 Long-lived Assets at December 31, United States $ 86,345 $ 92,509 $ 97,226 Canada 3,841 6,972 6,357 Europe 26,130 22,883 27,226 Asia Pacific 4,060 3,726 3,162 Total $ 120,376 $ 126,090 $ 133,971

Supplementary Financial Infor53

Supplementary Financial Information (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Supplementary Financial Information (unaudited)
Unaudited financial data for quarterly operations	(Unaudited) December 31, 2017 (Unaudited) December 31, 2016 $ in thousands, expect per share Fourth Third Second First Fourth Third Second First amounts Quarter Quarter Quarter Quarter Quarter Quarter Quarter Quarter Total revenues $ 126,747 $ 114,531 $ 121,581 $ 120,835 $ 119,589 $ 104,185 $ 120,610 $ 124,668 Expenses: Compensation and employee benefits 45,283 46,755 45,994 46,684 42,980 45,127 48,315 52,464 Transaction processing 26,981 23,428 25,482 24,856 24,540 20,799 22,098 22,834 Occupancy and equipment 23,316 14,945 14,680 15,622 14,296 13,849 14,066 13,978 Telecommunications and data processing services 12,132 12,189 12,129 12,027 13,302 13,720 14,848 14,773 Restructuring charges — — — — 5,265 — 4,355 — Other general and administrative 18,957 18,670 17,699 17,315 20,803 37,927 26,014 23,722 Interest expense 496 499 510 520 549 561 572 535 Total expenses 127,165 116,486 116,494 117,024 121,735 131,983 130,268 128,306 (Loss) income before income tax expense (benefit) (418) (1,955) 5,087 3,811 (2,146) (27,798) (9,658) (3,638) Income tax (benefit) expense 2,000 45,012 444 (1,491) (7,862) (3,887) (4,441) (1,132) Net (loss) income $ (2,418) $ (46,967) $ 4,643 $ 5,302 $ 5,716 $ (23,911) $ (5,217) $ (2,506) Basic (loss) income per share $ (0.07) $ (1.42) $ 0.14 $ 0.16 $ 0.18 $ (0.73) $ (0.16) $ (0.08) Diluted (loss) income per share $ (0.07) $ (1.42) $ 0.14 $ 0.16 $ 0.17 $ (0.73) $ (0.16) $ (0.08) Basic weighted average number of common shares outstanding 32,855 33,105 33,125 32,949 32,607 32,725 33,189 33,106 Diluted weighted average number of common shares outstanding 32,855 33,105 34,222 34,130 33,988 32,725 33,189 33,106 Earnings per share for quarterly periods are based on the weighted average common shares outstanding in individual quarters; thus, the sum of earnings per share of the quarters may not equal the amounts reported for the full year. (Unaudited) December 31, 2017 (Unaudited) December 31, 2016 Fourth Third Second First Fourth Third Second First As a percentage of Total Revenues Quarter (a)(b) (c) Quarter (c)(d) Quarter Quarter Quarter (e)(f)(g) Quarter (e) Quarter (h) Quarter (h) Total revenues 100 % 100.0 % 100.0 % 100.0 % 100.0 % 100.0 % 100.0 % 100.0 % Expenses: Compensation and employee benefits 35.7 40.8 37.8 38.6 35.9 43.3 40.1 42.1 Transaction processing 21.3 20.5 21.0 20.6 20.5 20.0 18.3 18.3 Occupancy and equipment 18.4 13.0 12.1 12.9 12.0 13.3 11.7 11.2 Telecommunications and data processing services 9.6 10.6 10.0 10.0 11.1 13.2 12.3 11.8 Restructuring charges — — — — 4.4 — 3.6 — Other general and administrative 15.0 16.3 14.6 14.3 17.4 36.4 21.6 19.0 Interest expense 0.4 0.4 0.4 0.4 0.5 0.5 0.5 0.4 Total expenses 100.4 101.6 95.9 96.8 101.8 126.7 108.1 102.8 (Loss) income before income tax expense (benefit) (0.4) (1.6) 4.1 3.2 (1.8) (26.7) (8.1) (2.8) Income tax (benefit) expense 1.6 39.3 0.4 (1.2) (6.6) (3.7) (3.7) (0.9) Net (loss) income (2.0) % (40.9) % 3.7 % 4.4 % 4.8 % (23.0) % (4.4) % (1.9) % (a) In the fourth quarter of 2017, the Company incurred an $8.1 million charge for the write-off of fixed assets and other costs associated with the consolidation of ITG’s New York office space. (b) In the fourth quarter of 2017, the Company reduced the amount recorded for a deferred tax liability in the U.S. due to the passing of the Tax Cuts and Jobs Act, which lowered the U.S. corporate income tax rate from 35% to 21%. (c) In the third quarter of 2017, the Company determined that it was appropriate to establish a full valuation allowance on its U.S. deferred tax assets, of which $42.3 million related to periods prior to the third quarter of 2017. In the fourth quarter of 2017, the Company reduced the valuation allowance by $0.9 million as a portion of these U.S. deferred tax assets were realized following a tax method change. (d) In the third quarter of 2017, the Company deemed the remaining value of a customer intangible asset recorded in ITG Derivatives of $0.3 million fully impaired and incurred legal fees related to the planned formation of the Matrix derivatives venture of $0.8 million. (e) During the third and fourth quarters of 2016, the Company accrued $22.1 million and $2.4 million, respectively, for a settlement with the SEC with respect to an inquiry involving pre-released ADRs and incurred legal and other related costs associated with this matter of $1.6 million and $1.3 million, respectively. (f) During the fourth quarter of 2016, the Company incurred restructuring charges of $5.3 million related to management delayering and the elimination of certain positions. During the second quarter of 2016, the Company incurred restructuring charges of $4.3 million related to (a) the reduction in its single stock sales trading and sales organizations and (b) the closing of its U.S. matched-book securities lending operations and its Canadian arbitrage trading desk. (g) During the fourth quarter of 2016, the Company resolved a multi-year tax contingency in the U.S. and reduced tax reserves by $7.3 million. (h) During the first and second quarters of 2016, the Company incurred a charge of $4.8 million, net of an insurance recovery of $0.5 million, to settle an arbitration case with its former CEO and incurred legal fees of $2.7 million. In the third quarter of 2016, the Company recorded a reimbursement of $0.9 million of these legal fees from its insurance carrier.

Organization and Basis of Pre54

Organization and Basis of Presentation (Details)	12 Months Ended
	Dec. 31, 2017segmentitem
Number of reportable operating segments | segment	4
Minimum
Number of countries in which execution services are offered | item	50

Summary of Significant Accoun55

Summary of Significant Accounting Policies - Principles of Consolidation (Details)	12 Months Ended
	Dec. 31, 2017
Principles of Consolidation
Ownership percentage for equity method investments	20.00%
Interests in variable interest entities (as a percent)	0.00%
Maximum
Principles of Consolidation
Ownership percentage for equity method investments	50.00%
Ownership percentage for consolidation of affiliate	50.00%
Minimum
Principles of Consolidation
Ownership percentage for equity method investments	20.00%

Summary of Significant Accoun56

Summary of Significant Accounting Policies - Revenue Recognition, Cash and Cash Equivalents, and Securities Borrowed and Loaned (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)item
Revenue recognition
Additional fee on unspecified future software upgrades | $	$ 0
Number of revenue recognition criteria | item	4
Cash and Cash Equivalents
Maximum original maturity period of cash equivalents	3 months
Minimum
Revenue recognition
Term of agreement	1 year
Maximum
Revenue recognition
Term of agreement	3 years

Summary of Significant Accoun57

Summary of Significant Accounting Policies - Client Commission Arrangements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Client Commission Arrangements
Client commissions allocated for research	$ 96,300	$ 100,700	$ 110,900
Research receivable, gross	5,300	3,000	3,500
Allowance for research receivable	(100)	(100)	(100)
Research receivable, net of allowance	5,200	2,900	3,400
Accrued research payables	$ 51,275	$ 45,826	$ 46,300

Summary of Significant Accoun58

Summary of Significant Accounting Policies - Capitalized Software, Research and Development, Premises and Equipment and Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Research and Development
Research and development costs			$ 32.8	$ 31.8	$ 29.2
Corporate income tax rate as a percentage	35.00%		35.00%	35.00%	35.00%
Forecast
Research and Development
Corporate income tax rate as a percentage		21.00%
Furniture, fixtures and equipment | Minimum
Premises and equipment
Estimated useful life			3 years
Furniture, fixtures and equipment | Maximum
Premises and equipment
Estimated useful life			7 years
Proprietary software
Premises and equipment
Estimated useful life			3 years

Summary of Significant Accoun59

Summary of Significant Accounting Policies - Options and Common Stock (Details) - shares	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Common Stock Held in Treasury, at Cost
Common stock held in treasury, at cost; shares	20,038,809	19,830,032
Phantom share awards
Share-based compensation
Shares outstanding	0	0	57,798	358,349

Summary of Significant Accoun60

Summary of Significant Accounting Policies - Recently Adopted Accounting Standards (Details) $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)item	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Jan. 01, 2018USD ($)	Jan. 01, 2017USD ($)
Income tax benefit	$ (6,500)	$ (2,000)	$ (45,012)	$ (444)	$ 1,491	$ 7,862	$ 3,887	$ 4,441	$ 1,132	$ (45,965)	$ 17,322	$ (29,656)
Retained Earnings (Accumulated Deficit)		486,957				536,350				486,957	536,350
Increase in deferred tax assets		4,902				38,688				4,902	38,688
Additional paid-in capital		$ 250,216				$ 248,748				$ 250,216	$ 248,748
ASU 2016-09
Number of key accounting changes affect the timing of revenue recognition | item										2
Income tax benefit										$ 1,300
Retained Earnings (Accumulated Deficit)														$ (600)
Increase in deferred tax assets														300
Additional paid-in capital														$ 900
ASU 2014-09
Retained Earnings (Accumulated Deficit)													$ (40)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets
Securities owned, at fair value:	$ 1,559	$ 2,557
Liabilities
Securities sold, not yet purchased, at fair value:	1	249
Recurring basis
Assets
Total Assets	1,559	2,557
Liabilities
Securities sold, not yet purchased, at fair value:	1
Total Liabilities	1	249
Recurring basis | Corporate stocks-trading securities
Assets
Securities owned, at fair value:	78	244
Liabilities
Securities sold, not yet purchased, at fair value:		249
Recurring basis | Mutual funds
Assets
Securities owned, at fair value:	1,481	2,313
Recurring basis | Level 1
Assets
Total Assets	1,559	2,557
Liabilities
Securities sold, not yet purchased, at fair value:	1
Total Liabilities	1	249
Recurring basis | Level 1 | Corporate stocks-trading securities
Assets
Securities owned, at fair value:	78	244
Liabilities
Securities sold, not yet purchased, at fair value:		249
Recurring basis | Level 1 | Mutual funds
Assets
Securities owned, at fair value:	$ 1,481	$ 2,313

Divestitures and Acquisitions -

Divestitures and Acquisitions - Divestitures (Details) - USD ($)	May 27, 2017	May 27, 2016	Dec. 22, 2015	Dec. 31, 2015	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Divestitures
Revenues					$ 126,747,000	$ 114,531,000	$ 121,581,000	$ 120,835,000	$ 119,589,000	$ 104,185,000	$ 120,610,000	$ 124,668,000	$ 483,694,000	$ 469,052,000	$ 634,803,000
Impairment of intangible assets													$ 325,000
Ownership percentage for equity method investments					20.00%								20.00%
Legal and related costs															4,900,000
Pre-tax gain on sale														$ 21,000	$ 107,699,000
ITG Investment Research | Sale of subsidiaries
Divestitures
Cash proceeds from sale	$ 12,000,000	$ 12,000,000
Carrying value of net assets disposed		(7,502,000)
Direct selling costs		(4,477,000)
After-tax gain on sale of business													$ 50,000
Pre-tax gain on sale	$ 21,000	$ 21,000
Energy research business | Sale of subsidiaries
Divestitures
Number of years as exclusive sales partner			2 years
Currency translation losses			$ 200,000
Cash proceeds from sale			120,500,000	$ 120,500,000
Working capital adjustment			(1,615,000)
Carrying value of net assets disposed			(3,025,000)
Direct selling costs			(8,161,000)
After-tax gain on sale of business			91,400,000
Pre-tax gain on sale			$ 107,699,000	$ 107,700,000
Matrix Holding Group
Divestitures
Legal and related costs						800,000							800,000
ITG Derivatives
Divestitures
Revenues													5,300,000
Impairment of intangible assets						$ 300,000							$ 300,000

Restructuring Charges (Details)

Restructuring Charges (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Restructuring Charges
Balance at the beginning of the period	$ 3,157
Balance at the end of the period	6
Consolidation of leased facilities | Restructuring Plan 2016
Restructuring Charges
Balance at the beginning of the period	3,157
Utilized - cash	(3,119)
Accrual adjustment	(58)
Currency translation	26
Balance at the end of the period	$ 6

Goodwill and Other Intangible64

Goodwill and Other Intangibles - Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill
Balance at the beginning of the period	$ 10,102
Balance at the end of the period	11,054	$ 10,102
European Operations | Operating Segments
Goodwill
Balance at the beginning of the period	10,102	11,933
Currency translation adjustment	952	(1,831)
Balance at the end of the period	$ 11,054	$ 10,102

Goodwill and Other Intangible65

Goodwill and Other Intangibles - Other Intangible (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	May 31, 2016
Other Intangible Assets
Gross Carrying Amount		$ 42,456	$ 42,430
Accumulated Amortization		28,416	27,040
Other intangible assets not subject to amortization		8,900
Amortization expense of other intangible assets		1,276	1,852	$ 3,200
Impairment of intangible assets		325
Impairment of other intangible assets			0
Customer intangibles disposed					$ 6,700
Estimate of future amortization expense for acquired other intangibles
Total		14,040	15,390	$ 24,611
ITG Derivatives
Other Intangible Assets
Impairment of intangible assets	$ 300	300
Trade names
Other Intangible Assets
Gross Carrying Amount		8,529	8,518
Trading rights
Other Intangible Assets
Gross Carrying Amount		339	339
Other
Other Intangible Assets
Gross Carrying Amount		50	50
Estimate of future amortization expense for acquired other intangibles
2,018		1,017
2,019		865
2,020		653
2,021		571
2,022		571
Thereafter		1,447
Total		5,124
POSIT trade name
Other Intangible Assets
Other intangible assets not subject to amortization		8,400
Customer related intangibles
Other Intangible Assets
Gross Carrying Amount		10,217	10,358
Accumulated Amortization		$ 6,219	5,584
Useful Lives		16 years 10 months 24 days
Proprietary software
Other Intangible Assets
Gross Carrying Amount		$ 23,321	23,165
Accumulated Amortization		$ 22,197	$ 21,456
Useful Lives		8 years 4 months 24 days

Goodwill and Other Intangible66

Goodwill and Other Intangibles - Changes in Net Intangibles Carrying Amount (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill and Other Intangibles
Beginning balance	$ 15,390	$ 24,611
Amortization	(1,276)	(1,852)	$ (3,200)
Divestiture of energy research operations		(6,684)
Impairment charge	(325)
Currency translation adjustment	251	(685)
Ending balance	$ 14,040	$ 15,390	$ 24,611

Securities Owned and Sold, No67

Securities Owned and Sold, Not Yet Purchased (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Securities owned and sold, not yet purchased
Securities owned, at fair value	$ 1,559	$ 2,557
Securities sold, not yet purchased, at fair value	1	249
Corporate stocks-trading securities
Securities owned and sold, not yet purchased
Securities owned, at fair value	78	244
Securities sold, not yet purchased, at fair value	1	249
Mutual funds
Securities owned and sold, not yet purchased
Securities owned, at fair value	$ 1,481	$ 2,313

Income Taxes - Current and Defe

Income Taxes - Current and Deferred (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal											$ (423)	$ (9,918)	$ 5,731
State											1,072	(624)	(1,645)
Foreign											11,490	8,975	12,647
Total											12,139	(1,567)	16,733
Deferred:
Federal											25,797	(12,687)	13,665
State											7,694	(2,217)	2,570
Foreign											335	(851)	(3,312)
Total											33,826	(15,755)	12,923
Total, income tax expense (benefit)	$ 6,500	$ 2,000	$ 45,012	$ 444	$ (1,491)	$ (7,862)	$ (3,887)	$ (4,441)	$ (1,132)		45,965	(17,322)	29,656
Components of (Loss) income before income taxes
U.S.											(56,465)	(81,579)	51,797
Foreign											62,990	38,339	69,429
Income (loss) before income tax expense (benefit)		(418)	(1,955)	5,087	$ 3,811	(2,146)	$ (27,798)	$ (9,658)	$ (3,638)		6,525	(43,240)	$ 121,226
Deferred tax assets:
Compensation and benefits		5,912				9,715					5,912	9,715
Net operating loss and capital loss carryover		18,974				19,755					18,974	19,755
Share-based compensation		5,092				6,824					5,092	6,824
Research and development credits		7,438				7,550					7,438	7,550
Foreign tax credits		11,117				12,660					11,117	12,660
Tax benefits on uncertain tax positions		831				1,351					831	1,351
Goodwill and definite-lived intangibles		6,363				8,015					6,363	8,015
Depreciation		3,527				1,167					3,527	1,167
Capitalized software		383									383
Rent		3,013				3,695					3,013	3,695
Other		700				1,564					700	1,564
Total deferred tax assets		63,350				72,296					63,350	72,296
Less: valuation allowance		(58,448)				(20,979)					(58,448)	(20,979)
Total deferred tax assets, net of valuation allowance		4,902				51,317					4,902	51,317
Deferred tax liabilities:
Capitalized software						(12,174)						(12,174)
Indefinite-lived intangibles		(1,695)									(1,695)
Other		(55)				(455)					(55)	(455)
Total deferred tax liabilities		(1,750)				(12,629)					(1,750)	(12,629)
Net deferred tax assets		$ 3,152		42,300		38,688					$ 3,152	$ 38,688
Increase (decrease) in valuation allowance			$ 48,100
Corporate income tax rate as a percentage		35.00%									35.00%	35.00%	35.00%
Valuation allowance		$ 58,448				$ 20,979					$ 58,448	$ 20,979
Expire in 2024
Deferred tax assets:
Foreign tax credits		11,100									11,100
Expire In 2032
Deferred tax assets:
Research and development credits		7,400									7,400
U.S.
Deferred tax assets:
Less: valuation allowance		(37,700)		(42,300)							(37,700)
Deferred tax liabilities:
Increase (decrease) in valuation allowance		900
Valuation allowance		$ 37,700		$ 42,300							$ 37,700
Forecast
Deferred tax liabilities:
Corporate income tax rate as a percentage										21.00%

Income Taxes - Carryforwards (D

Income Taxes - Carryforwards (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Operating loss carryforwards
Operating loss carryforwards	$ 112,486
Maximum
Operating loss carryforwards
Net operating loss carryforwards, expiration period	20 years
Minimum
Operating loss carryforwards
Net operating loss carryforwards, expiration period	13 years
Non-U.S. jurisdictions
Operating loss carryforwards
Operating loss carryforwards	$ 76,375
U.S.
Operating loss carryforwards
Operating loss carryforwards	$ 36,111

Income Taxes - Reconciliation (

Income Taxes - Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S. federal statutory income tax rate and effective tax rate
U.S. federal statutory income tax rate (as a percent)	35.00%		35.00%	35.00%	35.00%
State and local income taxes, net of U.S. federal income tax effect (as a percent)			0.60%	5.20%	0.40%
Foreign tax impact, net (as a percent)			(81.80%)	6.20%	(7.20%)
Deemed dividend on capital structure amendment (as a percent)					5.40%
Valuation allowance			585.80%
Tax impact of Tax Cuts and Jobs Act			149.20%
Stock windfall/shortfall			(13.50%)
Impact of deductible basis on the sale of energy research business ( as a percent)					(14.80%)
Reserves released upon tax settlement				18.60%
Non-deductible costs (as a percent)			21.30%	(22.80%)	6.10%
Other, net (as a percent)			7.90%	(2.10%)	(0.40%)
Effective income tax rate (as a percent)			704.50%	40.10%	24.50%
Reconciliation of the beginning and ending amounts of unrecognized tax benefits
Balance, January 1		$ 7,693	$ 7,356	$ 15,553	$ 14,395
Additions based on tax positions related to the current year			591	66	2,807
Additions based on tax positions of prior years			4	406	349
Reductions for tax positions of prior years			(13)		(36)
Reductions due to settlements with taxing authorities			(64)	(2,153)	(1,773)
Reductions due to expiration of statute of limitations			(181)	(6,516)	(189)
Balance, December 31	$ 7,693		7,693	7,356	15,553
Amount of unrecognized tax benefits that was netted against fully reserved U.S. deferred tax assets	4,500		4,500
Accrued interest expense related to tax reserves, net of related tax effects	$ 2,100		2,100
Net (reductions) additions of unrecognized tax-related interest expense			100	(2,500)	(100)
Penalties recognized, as a component of income tax expense			$ 100	$ 0	$ 0
Forecast
U.S. federal statutory income tax rate and effective tax rate
U.S. federal statutory income tax rate (as a percent)		21.00%

Receivables and Payables - Brok

Receivables and Payables - Brokers, Dealers, and Clearing Organizations (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Receivables from brokers, dealers and clearing organizations
Broker-dealers	$ 189,817	$ 147,116
Clearing organizations	708	5,117
Securities borrowed	4,246	374
Allowance for doubtful accounts	(864)	(313)
Total	193,907	152,294
Payables to brokers, dealers and clearing organizations
Broker-dealers	105,022	56,894
Clearing organizations	10,011	8,096
Securities loaned	4,245	35,198
Total	$ 119,278	$ 100,188

Receivables and Payables - Cust

Receivables and Payables - Customers (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Receivables from customers
Customers	$ 75,062	$ 55,006
Allowance for doubtful accounts	(367)	(520)
Total	74,695	54,486
Payables to customers
Customers	23,568	12,272
Total	$ 23,568	$ 12,272

Receivables and Payables - Allo

Receivables and Payables - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for doubtful accounts
Provision for doubtful accounts	$ 375	$ 67	$ 496

Receivables and Payables - Secu

Receivables and Payables - Securities Borrowed and Loaned (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Securities Borrowed and Loaned
Interest earned	$ 1,961	$ 5,512
Interest incurred	(1,132)	(3,720)
Interest earned (incurred), net	$ 829	$ 1,792

Receivables and Payables - Mast

Receivables and Payables - Master Securities Lending Agreements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deposits paid for securities borrowed
Gross Amounts of Recognized Assets	$ 4,246	$ 374
Net Amounts Presented in the Consolidated Statement of Financial Condition	4,246	374
Collateral Received or Pledged (including Cash)	4,246	374
Deposits received for securities loaned
Gross Amounts of Recognized Liabilities	(4,245)	(35,198)
Net Amounts Presented in the Consolidated Statement of Financial Condition	(4,245)	(35,198)
Collateral Received or Pledged (including Cash)	(4,229)	(34,245)
Net Amount	(16)	(953)
Equity Securities
Deposits received for securities loaned
Gross Amounts of Recognized Liabilities	$ (4,200)	$ (34,300)

Premises and Equipment (Details

Premises and Equipment (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)floor	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Premises and equipment
Premises and equipment, gross	$ 194,909	$ 210,210
Less: accumulated depreciation and amortization	140,949	150,877
Total	53,960	59,333
Depreciation and amortization expense	18,300	16,500	$ 16,300
Reduction in premises and equipment costs	30,600
Reduction in accumulated depreciation and amortization	10,200
Written off of leasehold assets	$ 7,492
Number of leasehold floors available before write off | floor	3
Number of floors available after written off | floor	2
Furniture, fixtures and equipment
Premises and equipment
Premises and equipment, gross	$ 149,366	157,770
Leasehold improvements
Premises and equipment
Premises and equipment, gross	$ 45,543	$ 52,440

Capitalized Software (Details)

Capitalized Software (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Capitalized Software
Capitalized software costs	$ 86,316	$ 82,877
Less: accumulated amortization	45,057	44,271
Total	41,259	38,606
Capitalization of software development costs	27,782	24,617	$ 26,003
Reduction in capitalized software costs and related accumulated amortization for fully amortized costs that are no longer in use	25,000
Capitalized software costs not subject to amortization	0	0
Amortization of capitalized software costs	$ 25,600	$ 25,100	$ 24,600

Accounts Payable and Accrued 78

Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts Payable and Accrued Expenses
Accrued research payables	$ 51,275	$ 45,826	$ 46,300
Accrued compensation and benefits	37,911	34,526
Accrued settlement costs		24,450
Accrued rent	14,821	19,061
Trade payables	20,820	14,474
Deferred revenue	8,057	7,643
Deferred compensation	2,525	3,262
Accrued restructuring	6	3,157
Accrued transaction processing	3,257	3,230
Other	27,823	18,714
Total	$ 166,495	$ 174,343

Borrowings - Security and Settl

Borrowings - Security and Settlement (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Borrowings
Outstanding short-term bank loans to support clearance and settlement activities	$ 101,422	$ 72,150
Weighted average interest rate on outstanding short-term bank loans to support clearance and settlement activities (as a percent)	2.33%

Borrowings - Credit Agreement (

Borrowings - Credit Agreement (Details) - USD ($) $ in Thousands	Jan. 26, 2018	Dec. 31, 2017	Dec. 31, 2016
Term Debt
Term loans		$ 3,104	$ 3,098
Obligations under capital lease			3,269
Total		3,104	6,367
Revolving Credit
Credit Agreement
Current borrowing capacity	$ 150,000
Credit facility initial term	364 days
Unused commitment fee (as a percent)	0.75%
Incremental interest rate payable in event of default (as a percent)	2.00%
Amount outstanding under Credit Agreement		$ 0	$ 0
Revolving Credit | Subsequent event
Credit Agreement
Current borrowing capacity	$ 150,000
Credit facility initial term	364 days
Revolving Credit | Federal funds rate
Credit Agreement
Interest, margin over base rate (as a percent)	2.50%

Borrowings - Term Loan and Mast

Borrowings - Term Loan and Master Lease Agreement (Details)	Dec. 21, 2017USD ($)installment	Dec. 30, 2015USD ($)installment	Jul. 29, 2013USD ($)	Jun. 01, 2011USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	May 31, 2015USD ($)	Aug. 10, 2012USD ($)
Master Lease Agreement
Obligations under capital lease						$ 3,269,000
Interest expense including amortization of debt issuance costs and net settlement payments on interest rate swaps					$ 2,000,000	$ 2,200,000	$ 1,800,000
H-P Loan
Term Loan
Term of Term Loan Agreement		5 years
Term debt		$ 3,600,000
Number of quarterly installments for payable of remaining loan principal | installment		20
Repayment of principal in quarterly installments		$ 195,000
Schedule of remaining principal payments
2,018					715,000
2,019					737,000
2,020					759,000
2,021					193,000
Total					2,404,000
Master Lease Agreement
Accrued interest (as a percent)		2.95%
H-P Veritas Loan
Term Loan
Term of Term Loan Agreement	3 years
Term debt	$ 700,000
Number of quarterly installments for payable of remaining loan principal | installment	3
H-P Veritas Loan | Principal payable in January 2018
Term Loan
Repayment of principal in quarterly installments					239,996
H-P Veritas Loan | Principal payable in January 2019
Term Loan
Repayment of principal in quarterly installments					229,994
H-P Veritas Loan | Principal payable in March 2019
Term Loan
Repayment of principal in quarterly installments					229,994
Equipment Loan Agreement
Term Loan
Term of Term Loan Agreement				4 years
Term debt				$ 25,500,000
Repayment of principal in quarterly installments								$ 530,600
Interest Rate								one month LIBOR rate for dollar deposits
Master Lease Agreement
Accrued interest (as a percent)								3.00%
Master Lease Agreement
Master Lease Agreement
Master lease facility, amount					$ 5,000,000				$ 25,000,000
Obligations under capital lease			$ 21,200,000
Accrued interest (as a percent)			3.39%
Term of capital lease			48 months		48 months
Ending purchase price of underlying assets			$ 1						$ 1

Accumulated Other Comprehensi82

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive (Loss) Income
Beginning Balance	$ (33,977)	$ (19,495)
Other comprehensive loss before reclassifications	12,580	(13,416)
Amounts reclassified from accumulated other comprehensive loss		(1,066)
Other comprehensive income (loss)	12,580	(14,482)	$ (13,601)
Ending Balance	$ (21,397)	(33,977)	$ (19,495)
Currency translation adjustment
Accumulated Other Comprehensive (Loss) Income
Amounts reclassified from accumulated other comprehensive loss		$ (1,100)

Net Capital Requirement (Detail

Net Capital Requirement (Details)	Dec. 31, 2017USD ($)
Canadian Operations
Net Capital Requirement
Net Capital	$ 24,450,000
Excess Net Capital	24,050,000
Ireland
Net Capital Requirement
Net Capital	46,030,000
Excess Net Capital	12,278,000
U.K.
Net Capital Requirement
Net Capital	2,036,000
Excess Net Capital	1,025,000
Australia
Net Capital Requirement
Net Capital	27,008,000
Excess Net Capital	17,591,000
Hong Kong
Net Capital Requirement
Net Capital	5,993,000
Excess Net Capital	5,538,000
Singapore
Net Capital Requirement
Net Capital	1,121,000
Excess Net Capital	1,047,000
ITG Inc.
Net Capital Requirement
Minimum net capital under the alternative method	$ 1,000,000
Net capital percentage of debit balances arising from customer transactions	2.00%
Cash balance in Special Reserve Bank Accounts for the benefit of customers under the Customer Protection Rule	$ 9,200,000
Cash balance under Proprietary Accounts for Introducing Brokers agreements	2,500,000
ITG Inc. | U.S. Operations
Net Capital Requirement
Net Capital	86,165,000
Excess Net Capital	$ 85,165,000
Alter Net
Net Capital Requirement
Net capital percentage of aggregate indebtedness	6.66%
Minimum net capital under the basic method	$ 100,000
Alter Net | U.S. Operations
Net Capital Requirement
Net Capital	4,300,000
Excess Net Capital	$ 4,200,000
ITG Derivatives
Net Capital Requirement
Net capital percentage of aggregate indebtedness	6.66%
ITG Derivatives | U.S. Operations
Net Capital Requirement
Net Capital	$ 579,000
Excess Net Capital	$ 479,000

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stock Repurchase Program
Total Shares Repurchased					500,000	400,000	400,000
Shares Repurchased Under Board Authorization					885,285	1,336,132	1,992,831
Total cost (in dollars)					$ 16.9	$ 22.1	$ 42
Average share price (in dollars per share)					$ 19.13	$ 16.55	$ 21.10
Shares withheld for net settlements of share-based awards, shares					531,346	391,195	418,135
Dividend Program
Dividend declared (in dollars per share)	$ 0.07	$ 0.07	$ 0.07	$ 0.07
Dividend paid (in dollars per share)	$ 0.07	$ 0.07	$ 0.07	$ 0.07
Aggregate cash dividends					$ 9.2
Aggregate stock dividends					$ 0.1
May 2,013
Stock Repurchase Program
Number of shares authorized to repurchase by Board (in shares)	4,000,000				4,000,000
Total Shares Repurchased					4,000,000
Shares Repurchased Under Board Authorization							800,000
October 2,014
Stock Repurchase Program
Number of shares authorized to repurchase by Board (in shares)	4,000,000				4,000,000
Total Shares Repurchased					3,400,000
Shares remaining under Board Authorization	600,000				600,000
Shares Repurchased Under Board Authorization					900,000	1,300,000	1,200,000

Employee and Non-Employee Dir85

Employee and Non-Employee Director Stock and Benefit Plans - Stock Options/2007 Plan (Details)	1 Months Ended	7 Months Ended	12 Months Ended
	Aug. 31, 2016USD ($)	Jul. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2017installmentitem$ / sharesshares	Dec. 31, 2016$ / sharesshares	Dec. 31, 2015$ / sharesshares
Employee and non-employee director stock and benefit plans
Number of new hire award or portion thereof shall vest prior to the one-year anniversary of the date of grant as expected | item			0
Number of Shares
Exercised (in shares)				(24,498)	(39,002)
Stock options
Number of Shares
Outstanding at the beginning of the period (in shares)		42,665	196,851	42,665	306,853
Granted (in shares)			0	196,851
Exercised (in shares)				(42,665)	(71,455)
Forfeited (in shares)					(192,733)
Outstanding at the end of the period (in shares)			196,851	196,851	42,665
Amount exercisable at the end of the period (in shares)			65,630		42,665
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share) | $ / shares		$ 12.17	$ 16.18	$ 12.17	$ 17.23
Granted (in dollars per share) | $ / shares				16.18
Exercised (in dollars per share) | $ / shares				12.17	16.26
Forfeited (in dollars per share) | $ / shares					18.71
Outstanding at the end of the period (in dollars per share) | $ / shares			16.18	$ 16.18	12.17
Amount exercisable at the end of the period (in dollars per share) | $ / shares			$ 16.18		$ 12.17
2007 Plan
Employee and non-employee director stock and benefit plans
Shares of common stock authorized			3,123,105
Directors' Equity Subplan | Restricted stock unit awards
Employee and non-employee director stock and benefit plans
Value of shares granted at or shortly after the time of appointment | $	$ 120,000	$ 100,000
Value of shares granted on the forty fifth day following each of the annual meetings of stockholders | $	$ 80,000
Chief Executive Officer | Time-based award
Employee and non-employee director stock and benefit plans
Expiration period (in years)			8 years
Number of equal annual vesting installments | installment			3
Number of Shares
Granted (in shares)				196,851

Employee and Non-Employee Dir86

Employee and Non-Employee Director Stock and Benefit Plans - Range of Exercise Price (Details) - Exercise Price Of 16.18 - Stock options	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Range of Exercise Prices
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 16.18
Number Outstanding (in shares) | shares	196,851
Weighted Average Remaining Contractual Life	6 years 15 days
Weighted Average Exercise Price (in dollars per share)	$ 16.18
Number Exercisable (in shares) | shares	65,630
Weighted Average Exercise Price (in dollars per share)	$ 16.18

Employee and Non-Employee Dir87

Employee and Non-Employee Director Stock and Benefit Plans - Stock Based Awards (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)installmentshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)shares
Employee and non-employee director stock and benefit plans
Stock options exercised | shares		24,498	39,002
Share-based awards, additional disclosures
Total intrinsic value of stock options exercised		$ 220	$ 370
Weighted average grant date fair value of stock options granted during period, per share (in dollars per share) | $ / shares		$ 16.18
Cash received from stock option exercises		$ 208	298
Number of installments | installment	2
Stock options
Employee and non-employee director stock and benefit plans
Share-based compensation expense	$ 300	300	0
Tax benefit related to share-based compensation expense	$ 0	$ 100	$ 100
Weighted average remaining contractual term of stock options currently exercisable	6 years
Amount exercisable at the end of the period (in shares) | shares	65,630		42,665
Tax shortfall from stock options exercises and cancellation			$ 600
Stock options exercised | shares		42,665	71,455
Share-based awards, additional disclosures
Intrinsic value of outstanding stock options	$ 600
Intrinsic value of exercisable stock options	200
Unrecognized compensation costs	$ 300
Weighted average period over which unrecognized compensation costs are expected to be recognized	1 year
Restricted share awards
Employee and non-employee director stock and benefit plans
Share-based compensation expense	$ 19,600	$ 24,900	$ 16,400
Tax benefit related to share-based compensation expense	900	$ 8,900	$ 6,600
Share-based awards, additional disclosures
Unrecognized compensation costs	$ 25,800
Weighted average period over which unrecognized compensation costs are expected to be recognized	1 year 3 months 18 days
2007 Plan | Restricted share awards | Vesting on January 31, 2017
Share-based awards, additional disclosures
Vesting percent	33.33%
2007 Plan | Restricted share awards | Vesting on January 31, 2018
Share-based awards, additional disclosures
Vesting percent	66.67%
Equity Deferral Award Program (EDA)
Share-based awards, additional disclosures
Percentage of matching units granted on grant date prior to 2012	10.00%
Equity Deferral Award Program (EDA) | Time-based award
Share-based awards, additional disclosures
Percentage of matching units granted on third anniversary of grant date	100.00%
Period preceding the grant date during which the entity's average stock price is assessed in determining the vesting of an award to the recipient	90 days
Period during which the Company's average stock price is assessed in determining the vesting of an award to the recipient	90 days
Equity Deferral Award Program (EDA) | Market-based award
Share-based awards, additional disclosures
Period preceding the grant date during which the entity's average stock price is assessed in determining the vesting of an award to the recipient	90 days
Period during which the Company's average stock price is assessed in determining the vesting of an award to the recipient	90 days
Percentage of deferred compensation representing the match that vests on fourth anniversary	100.00%

Employee and Non-Employee Dir88

Employee and Non-Employee Director Stock and Benefit Plans - Compensation/Restructuring Charges (Details) - Restricted share awards - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Compensation expense
Share-based compensation expense	$ 19.6	$ 24.9	$ 16.4
Tax benefit related to share-based compensation expense	$ 0.9	$ 8.9	$ 6.6

Employee and Non-Employee Dir89

Employee and Non-Employee Director Stock and Benefit Plans - Share Awards (Details) $ / shares in Units, $ in Millions	May 27, 2016USD ($)shares	Dec. 22, 2015shares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)installmentitem$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares
Chief Executive Officer
Employee and non-employee director stock and benefit plans
Number of Inducement Awards granted | item				2
Restricted share awards
Total Number of Shares
Outstanding at the beginning of the period (in shares)			3,063,264	3,171,036	2,659,228
Granted (in shares)			1,259,392	1,665,916	2,196,191
Vested (in shares)			(1,331,021)	(1,042,238)	(1,159,047)
Forfeited (in shares)			(84,090)	(731,450)	(525,336)
Outstanding at the end of the period (in shares)			2,907,545	3,063,264	3,171,036
Weighted Average Grant Date Fair Value
Outstanding at the beginning of the period (in dollars per share) | $ / shares			$ 16.63	$ 16.75	$ 13.51
Granted (in dollars per share) | $ / shares			19.81	16.16	18.79
Vested (in dollars per share) | $ / shares			16.60	16.06	13.49
Forfeited (in dollars per share) | $ / shares			18.99	16.88	16.10
Outstanding at the end of the period (in dollars per share) | $ / shares			$ 18.10	$ 16.63	$ 16.75
Additional disclosures
Number of unvested shares converted into vested shares upon divestiture			1,331,021	1,042,238	1,159,047
Unrecognized compensation costs | $			$ 25.8
Weighted average period over which unrecognized compensation costs are expected to be recognized			1 year 3 months 18 days
Grant date fair value | $			$ 21.9
Tax benefits related to the vesting | $			1.5	$ 0.8	$ 2.9
Tax shortfalls | $			0.1	0.7	0.3
Share-based compensation expense | $			19.6	24.9	16.4
Tax benefit related to share-based compensation expense | $			$ 0.9	$ 8.9	$ 6.6
ROE-Based Market Based Or Performance Based
Total Number of Shares
Outstanding at the beginning of the period (in shares)			342,370	377,475	438,022
Granted (in shares)			140,796	228,895	263,766
Vested (in shares)			(51,498)	(73,243)	(97,112)
Forfeited (in shares)			(38,324)	(190,757)	(227,201)
Outstanding at the end of the period (in shares)			393,344	342,370	377,475
Additional disclosures
Number of unvested shares converted into vested shares upon divestiture			51,498	73,243	97,112
Performance-based share awards
Total Number of Shares
Outstanding at the end of the period (in shares)			140,796
Market-based share awards
Total Number of Shares
Outstanding at the end of the period (in shares)			45,065
Time-Based Restricted Stock Units
Total Number of Shares
Outstanding at the beginning of the period (in shares)			2,720,894	2,793,561	2,221,206
Granted (in shares)			1,118,596	1,437,021	1,932,425
Vested (in shares)			(1,279,523)	(968,995)	(1,061,935)
Forfeited (in shares)			(45,766)	(540,693)	(298,135)
Outstanding at the end of the period (in shares)			2,514,201	2,720,894	2,793,561
Additional disclosures
Number of unvested shares converted into vested shares upon divestiture			1,279,523	968,995	1,061,935
ROE-Based Restricted Stock Units
Total Number of Shares
Outstanding at the end of the period (in shares)			207,483
Restricted Stock, Inducement Awards, Tranche One [Member] | Chief Executive Officer
Total Number of Shares
Granted (in shares)				135,353
Additional disclosures
Number of equal annual vesting installments | installment				3
Restricted Stock, Inducement Awards, Tranche Two [Member] | Chief Executive Officer
Total Number of Shares
Granted (in shares)				156,051
Restricted Stock, Inducement Awards, Tranche Two [Member] | Chief Executive Officer | Vesting on January 31, 2016
Additional disclosures
Vesting percent				38.00%
Vesting period				12 months
Restricted Stock, Inducement Awards, Tranche Two [Member] | Chief Executive Officer | Vesting on January 31, 2017
Additional disclosures
Vesting percent				41.00%
Restricted Stock, Inducement Awards, Tranche Two [Member] | Chief Executive Officer | Vesting on January 31, 2018
Additional disclosures
Vesting percent				21.00%
Phantom share awards
Total Number of Shares
Outstanding at the beginning of the period (in shares)			0	57,798	358,349
Granted (in shares)			0
Vested (in shares)				(57,798)	(257,279)
Forfeited (in shares)					(43,272)
Outstanding at the end of the period (in shares)			0	0	57,798
Weighted Average Grant Date Fair Value
Outstanding at the beginning of the period (in dollars per share) | $ / shares				$ 12.24	$ 11.61
Vested (in dollars per share) | $ / shares				$ 12.24	11.58
Forfeited (in dollars per share) | $ / shares					10.99
Outstanding at the end of the period (in dollars per share) | $ / shares					$ 12.24
Additional disclosures
Number of unvested shares converted into vested shares upon divestiture				57,798	257,279
2007 Plan | Restricted share awards | Vesting on January 31, 2017
Additional disclosures
Vesting percent			33.33%
2007 Plan | Restricted share awards | Vesting on January 31, 2018
Additional disclosures
Vesting percent			66.67%
2007 Plan | Phantom share awards
Additional disclosures
Share-based compensation expense | $				$ 0.1	$ 2.2
Tax benefit related to share-based compensation expense | $				$ 0.1	0.8
Sale of subsidiaries | ITG Investment Research | Restricted share awards
Total Number of Shares
Vested (in shares)	(226,802)
Additional disclosures
Number of unvested shares converted into vested shares upon divestiture	226,802
Cost to modify the vesting schedule | $	$ 0.7
Sale of subsidiaries | Energy research business | Restricted share awards
Total Number of Shares
Vested (in shares)		(113,718)
Additional disclosures
Number of unvested shares converted into vested shares upon divestiture		113,718
Other revenue | Sale of subsidiaries | Energy research business
Additional disclosures
Cost to modify the vesting schedule | $					$ 1.4

Employee and Non-Employee Dir90

Employee and Non-Employee Director Stock and Benefit Plans - Retirement Savings Plan (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee and Non Employee Director Benefit Plans
Director benefit plan, shares vested and deferred	$ 20,485
Retirement Savings Plan (RSP)
Employee and Non Employee Director Benefit Plans
In accordance with the Internal Revenue Code, the maximum annual eligible compensation under the plan, prior to January 1, 2011	$ 270,000
Company matching contribution, under the plan (as a percent)	50.00%
Maximum eligible compensation (as a percent)	4.00%
Benefit costs	$ 4,300,000	$ 4,400,000	$ 4,900,000
Directors' Retainer Fee Subplan
Employee and Non Employee Director Benefit Plans
Annual retainer fee received by non-employee directors, excluding the lead director and chairman, since 2006	70,000
Annual retainer fee received by lead director and chairman since August, 2008	$ 105,000
Deferred shares or units received	11,115	12,363	13,846
Deferred shares or units outstanding	130,940
Benefit costs	$ 800,000	$ 800,000	$ 1,200,000

Employee and Non-Employee Dir91

Employee and Non-Employee Director Stock and Benefit Plans - ESPP (Details) - ESPP - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Feb. 28, 1998	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee and non-employee director stock and benefit plans
Discount rate at which employees can purchase shares (as a percent)	15.00%
Share-based compensation expense		$ 0.3	$ 0.4	$ 0.3

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share
Net (loss) income for basic and diluted (loss) income per share	$ (2,418)	$ (46,967)	$ 4,643	$ 5,302	$ 5,716	$ (23,911)	$ (5,217)	$ (2,506)	$ (39,440)	$ (25,918)	$ 91,570
Shares of common stock and common stock equivalents:
Average common shares used in basic computation	32,855	33,105	33,125	32,949	32,607	32,725	33,189	33,106	33,009	32,906	33,907
Effect of dilutive securities (in shares)											908
Average common shares used in diluted computation	32,855	33,105	34,222	34,130	33,988	32,725	33,189	33,106	33,009	32,906	34,815
(Loss) income per share:
Basic (in dollars per share)	$ (0.07)	$ (1.42)	$ 0.14	$ 0.16	$ 0.18	$ (0.73)	$ (0.16)	$ (0.08)	$ (1.19)	$ (0.79)	$ 2.70
Diluted (in dollars per share)	$ (0.07)	$ (1.42)	$ 0.14	$ 0.16	$ 0.17	$ (0.73)	$ (0.16)	$ (0.08)	$ (1.19)	$ (0.79)	$ 2.63
Anti-dilutive equity awards not included in the detailed earnings per share computation
Equity awards not included in the diluted earnings per share computation									0	0	100

Commitments and Contingencies -

Commitments and Contingencies - Legal Matters (Details) $ in Thousands	Jan. 12, 2017USD ($)	Aug. 12, 2016item	Nov. 27, 2015item	Aug. 12, 2015USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2017item
Contingencies – Legal Matters
Accrued settlement costs					$ 24,450
Minimum
Contingencies – Legal Matters
Number of lawsuits proceedings may have a material impact on the results of operations for any particular period | item							1
Settlement Agreement With SEC Involving Prereleased ADRs
Contingencies – Legal Matters
Payment of settlement amount	$ 24,500
Disgorgement payment	15,100
Prejudgment interest	1,900
Civil penalty	$ 7,500
Accrued settlement costs					24,500
Litigation Settlement, Amount					$ (2,400)	$ (22,100)
Settlement with S E C for Investigation into Proprietary Trading Pilot
Contingencies – Legal Matters
Disgorgement payment				$ 2,100
Prejudgment interest				250
Civil penalty				18,000
Litigation Settlement, Amount				$ 20,300
Number of putative class action lawsuits | item		2
Case of derivative action captioned Watterson v. Gasser et al.
Contingencies – Legal Matters
Number of current or former officers and directors of the company got filed by the company | item			11

Commitments and Contingencies94

Commitments and Contingencies - Lease and Other Commitments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Contingencies - Legal Matters
Rent expense	$ 11,800	$ 12,700	$ 12,400
Maximum separation payments payable for early termination of employment arrangements without cause	6,000
Obligation to purchase market data, maintenance and other services	63,600
Minimum future rental commitments under non-cancelable operating leases
2,018	13,514
2,019	13,542
2,020	12,161
2,021	11,559
2,022	10,402
2023 and thereafter	60,301
Total	$ 121,479

Segment Reporting - Financial I

Segment Reporting - Financial Information (Details)	May 27, 2017USD ($)	May 27, 2016USD ($)	Dec. 22, 2015USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2016USD ($)	Jun. 30, 2016USD ($)	Dec. 31, 2017USD ($)segment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)
Segment reporting
Number of operating segments | segment															4
Total Revenues					$ 126,747,000	$ 114,531,000	$ 121,581,000	$ 120,835,000	$ 119,589,000	$ 104,185,000	$ 120,610,000	$ 124,668,000			$ 483,694,000	$ 469,052,000	$ 634,803,000
(Loss) income before income tax (benefit) expense					(418,000)	(1,955,000)	5,087,000	3,811,000	(2,146,000)	(27,798,000)	(9,658,000)	(3,638,000)			6,525,000	(43,240,000)	121,226,000
Identifiable assets				$ 1,709,022,000	784,856,000				775,285,000				$ 775,285,000		784,856,000	775,285,000	1,709,022,000
Capital purchases															19,402,000	21,315,000	11,905,000
Depreciation and amortization															45,153,000	43,523,000	44,151,000
Non-cash share-based compensation															20,238,000	25,620,000	16,667,000
Write off of fixed assets					8,100,000
Impairment of intangible assets															325,000
Tax charge				6,500,000	2,000,000	45,012,000	$ 444,000	$ (1,491,000)	(7,862,000)	(3,887,000)	(4,441,000)	(1,132,000)			45,965,000	(17,322,000)	29,656,000
Restructuring charges									5,265,000		4,355,000					9,620,000
Legal Fees																	4,900,000
Pre-tax gain on sale																21,000	107,699,000
Aggregate amount payable																		$ 20,300,000
Settlement agreement for termination of Former CEO
Segment reporting
Proceeds from insurer to settle claims										900,000
Legal Fees											2,700,000	2,700,000		$ 2,700,000
Net litigation settlement amount											(4,800,000)	(4,800,000)		(4,800,000)
Insurance recovery											500,000	$ 500,000		$ 500,000
Settlement Agreement With SEC Involving Prereleased ADRs
Segment reporting
Litigation settlement amount									2,400,000	22,100,000
Legal Fees									1,300,000	$ 1,600,000			2,900,000
Loss of Profits Due to Outage of Outsourced Primary Data Centre
Segment reporting
Proceeds from insurer to settle claims											2,400,000
Employee separation and related costs
Segment reporting
Restructuring charges									5,300,000
Reduction in trading and sales organizations and closing matched-book securities operations
Segment reporting
Restructuring charges											$ 4,300,000
Operating Segments | U.S. Operations
Segment reporting
Total Revenues															204,990,000	229,655,000	285,230,000
(Loss) income before income tax (benefit) expense															(24,473,000)	(11,133,000)	16,000,000
Identifiable assets				1,304,995,000	342,487,000				396,419,000				396,419,000		342,487,000	396,419,000	1,304,995,000
Capital purchases															13,278,000	15,547,000	7,748,000
Depreciation and amortization															33,307,000	32,896,000	33,971,000
Non-cash share-based compensation															9,543,000	10,642,000	10,725,000
Operating Segments | Canadian Operations
Segment reporting
Total Revenues															63,294,000	61,822,000	63,028,000
(Loss) income before income tax (benefit) expense															10,608,000	11,564,000	10,643,000
Identifiable assets				76,561,000	108,457,000				80,943,000				80,943,000		108,457,000	80,943,000	76,561,000
Capital purchases															1,183,000	2,549,000	2,175,000
Depreciation and amortization															2,420,000	2,402,000	2,247,000
Non-cash share-based compensation															2,390,000	2,383,000	1,466,000
Operating Segments | European Operations
Segment reporting
Total Revenues															151,472,000	125,945,000	129,729,000
(Loss) income before income tax (benefit) expense															41,103,000	25,470,000	28,244,000
Identifiable assets				262,095,000	274,836,000				236,071,000				236,071,000		274,836,000	236,071,000	262,095,000
Capital purchases															3,289,000	1,886,000	1,334,000
Depreciation and amortization															6,094,000	6,741,000	6,560,000
Non-cash share-based compensation															5,267,000	5,948,000	4,505,000
Operating Segments | Asia Pacific Operations
Segment reporting
Total Revenues															62,218,000	47,919,000	48,179,000
(Loss) income before income tax (benefit) expense															11,680,000	1,553,000	1,620,000
Identifiable assets				65,371,000	$ 59,076,000				$ 61,852,000				$ 61,852,000		59,076,000	61,852,000	65,371,000
Capital purchases															1,652,000	1,333,000	648,000
Depreciation and amortization															1,994,000	1,484,000	1,373,000
Non-cash share-based compensation															959,000	925,000	866,000
Corporate
Segment reporting
Total Revenues															1,720,000	3,711,000	108,637,000
(Loss) income before income tax (benefit) expense															(32,393,000)	(70,694,000)	64,719,000
Depreciation and amortization															1,338,000
Non-cash share-based compensation															2,079,000	$ 5,722,000	$ (895,000)
Matrix Holding Group
Segment reporting
Legal Fees						800,000									800,000
ITG Derivatives
Segment reporting
Total Revenues															5,300,000
Impairment of intangible assets						$ 300,000									$ 300,000
Sale of subsidiaries | Energy research business
Segment reporting
Cash proceeds from sale			$ 120,500,000	120,500,000
Pre-tax gain on sale			$ 107,699,000	$ 107,700,000
Sale of subsidiaries | ITG Investment Research
Segment reporting
Cash proceeds from sale	$ 12,000,000	$ 12,000,000
Pre-tax gain on sale	$ 21,000	$ 21,000

Segment Reporting - Revenue by

Segment Reporting - Revenue by Product Group (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues
Total Revenues	$ 126,747	$ 114,531	$ 121,581	$ 120,835	$ 119,589	$ 104,185	$ 120,610	$ 124,668	$ 483,694	$ 469,052	$ 634,803
Execution Services
Revenues
Total Revenues									344,192	328,252	386,158
Workflow Technology
Revenues
Total Revenues									92,533	92,891	94,117
Analytics
Revenues
Total Revenues									45,249	44,198	45,891
Corporate
Revenues
Total Revenues									$ 1,720	$ 3,711	$ 108,637

Segment Reporting - Long-lived

Segment Reporting - Long-lived Assets by Geographic Region (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment reporting
Long-lived Assets	$ 120,376	$ 126,090	$ 133,971
U.S. Operations
Segment reporting
Long-lived Assets	86,345	92,509	97,226
Canadian Operations
Segment reporting
Long-lived Assets	3,841	6,972	6,357
Europe
Segment reporting
Long-lived Assets	26,130	22,883	27,226
Asia Pacific Operations
Segment reporting
Long-lived Assets	$ 4,060	$ 3,726	$ 3,162

Supplementary Financial Infor98

Supplementary Financial Information - Expenses and Revenue (unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Supplementary Financial Information (unaudited)
Total Revenues		$ 126,747	$ 114,531	$ 121,581	$ 120,835	$ 119,589	$ 104,185	$ 120,610	$ 124,668	$ 483,694	$ 469,052	$ 634,803
Expenses:
Compensation and employee benefits		45,283	46,755	45,994	46,684	42,980	45,127	48,315	52,464	184,716	188,886	209,323
Transaction processing		26,981	23,428	25,482	24,856	24,540	20,799	22,098	22,834	100,747	90,271	91,492
Occupancy and equipment		23,316	14,945	14,680	15,622	14,296	13,849	14,066	13,978	68,563	56,189	57,495
Telecommunications and data processing services		12,132	12,189	12,129	12,027	13,302	13,720	14,848	14,773	48,477	56,643	51,523
Restructuring charges						5,265		4,355			9,620
Other general and administrative		18,957	18,670	17,699	17,315	20,803	37,927	26,014	23,722	72,641	108,466	101,915
Interest expense		496	499	510	520	549	561	572	535	2,025	2,217	1,829
Total expenses		127,165	116,486	116,494	117,024	121,735	131,983	130,268	128,306
Income (loss) before income tax expense (benefit)		(418)	(1,955)	5,087	3,811	(2,146)	(27,798)	(9,658)	(3,638)	6,525	(43,240)	121,226
Income tax expense (benefit)	$ 6,500	2,000	45,012	444	(1,491)	(7,862)	(3,887)	(4,441)	(1,132)	45,965	(17,322)	29,656
Net (loss) income		$ (2,418)	$ (46,967)	$ 4,643	$ 5,302	$ 5,716	$ (23,911)	$ (5,217)	$ (2,506)	$ (39,440)	$ (25,918)	$ 91,570
Basic (loss) income per share (in dollars per share)		$ (0.07)	$ (1.42)	$ 0.14	$ 0.16	$ 0.18	$ (0.73)	$ (0.16)	$ (0.08)	$ (1.19)	$ (0.79)	$ 2.70
Diluted (loss) income per share (in dollars per share)		$ (0.07)	$ (1.42)	$ 0.14	$ 0.16	$ 0.17	$ (0.73)	$ (0.16)	$ (0.08)	$ (1.19)	$ (0.79)	$ 2.63
Basic weighted average number of common shares outstanding (in shares)		32,855	33,105	33,125	32,949	32,607	32,725	33,189	33,106	33,009	32,906	33,907
Diluted weighted average number of common shares outstanding (in shares)		32,855	33,105	34,222	34,130	33,988	32,725	33,189	33,106	33,009	32,906	34,815

Supplementary Financial Infor99

Supplementary Financial Information - Expenses as a Percent (unaudited) (Details) - USD ($) $ in Thousands	Aug. 12, 2015	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Total revenues (as a percent)		100.00%	100.00%	100.00%	100.00%	100.00%	100.00%	100.00%	100.00%
Expenses (as a percent)
Compensation and employee benefits (as a percent)		35.70%	40.80%	37.80%	38.60%	35.90%	43.30%	40.10%	42.10%
Transaction processing (as a percent)		21.30%	20.50%	21.00%	20.60%	20.50%	20.00%	18.30%	18.30%
Occupancy and equipment (as a percent)		18.40%	13.00%	12.10%	12.90%	12.00%	13.30%	11.70%	11.20%
Telecommunications and data processing services (as a percent)		9.60%	10.60%	10.00%	10.00%	11.10%	13.20%	12.30%	11.80%
Restructuring charges (as a percent)						4.40%		3.60%
Other general and administrative (as a percent)		15.00%	16.30%	14.60%	14.30%	17.40%	36.40%	21.60%	19.00%
Interest expense (as a percent)		0.40%	0.40%	0.40%	0.40%	0.50%	0.50%	0.50%	0.40%
Total expenses (as a percent)		100.40%	101.60%	95.90%	96.80%	101.80%	126.70%	108.10%	102.80%
Income (loss) before income tax expense		(0.40%)	(1.60%)	4.10%	3.20%	(1.80%)	(26.70%)	(8.10%)	(2.80%)
Income tax expense (as a percent)		1.60%	39.30%	0.40%	(1.20%)	(6.60%)	(3.70%)	(3.70%)	(0.90%)
Net income (loss) (as a percent)		(2.00%)	(40.90%)	3.70%	4.40%	4.80%	(23.00%)	(4.40%)	(1.90%)
Write off of fixed assets		$ 8,100
Corporate income tax rate as a percentage		35.00%											35.00%	35.00%	35.00%
Valuation allowance		$ 58,448				$ 20,979				$ 20,979			$ 58,448	$ 20,979
Net deferred tax assets		3,152		$ 42,300		38,688				38,688			3,152	38,688
Increase (decrease) in valuation allowance			$ 48,100
Legal and other settlement related costs															$ 4,900
Impairment of intangible assets													325
Restructuring charges						5,265		$ 4,355						9,620
Decrease in income tax reserve due to resolution of uncertain tax positions						7,300				7,300				$ 7,300
Matrix Holding Group
Expenses (as a percent)
Legal and other settlement related costs			800										800
ITG Derivatives
Expenses (as a percent)
Impairment of intangible assets			$ 300										300
Settlement agreement for termination of Former CEO
Expenses (as a percent)
Legal and other settlement related costs								2,700	$ 2,700		$ 2,700
Net settlement charge								4,800	4,800		4,800
Insurance recovery								500	$ 500		$ 500
Proceeds from insurer to settle claims							$ 900
Settlement Agreement With SEC Involving Prereleased ADRs
Expenses (as a percent)
Legal and other settlement related costs						1,300	1,600			$ 2,900
Litigation settlement amount						2,400	$ 22,100
Settlement with S E C for Investigation into Proprietary Trading Pilot
Expenses (as a percent)
Litigation settlement amount	$ (20,300)
Employee separation and related costs
Expenses (as a percent)
Restructuring charges						$ 5,300
Reduction in trading and sales organizations and closing matched-book securities operations
Expenses (as a percent)
Restructuring charges								$ 4,300
Forecast
Expenses (as a percent)
Corporate income tax rate as a percentage												21.00%
U.S.
Expenses (as a percent)
Valuation allowance		37,700		$ 42,300									$ 37,700
Increase (decrease) in valuation allowance		$ 900

Subsequent Event (Details)

Subsequent Event (Details) - USD ($) shares in Millions, $ in Millions	Jan. 26, 2018	Feb. 15, 2018	Dec. 31, 2017
Subsequent event
Subsequent Events
Additional shares authorized to repurchase by Board (in shares)		4
Number of shares available for repurchase (in shares)		4.4
Revolving Credit
Subsequent Events
Current borrowing capacity	$ 150
Credit facility initial term	364 days
Revolving Credit | Subsequent event
Subsequent Events
Current borrowing capacity	$ 150
Credit facility initial term	364 days
Matrix Holding Group
Subsequent Events
Carrying value of net assets			$ 2