Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities
Net Income (loss)	$ 620,192	$ 18,898	$ 158,340
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	61,154	47,327	29,703
Amortization of purchased intangibles and acquired capitalized software	26,123	15,447	211
Debt issue cost related to debt refinancing and prepayment	10,645	10,460	5,579
Amortization of debt issuance costs and deferred financing fees	10,419	5,822	1,690
Termination of office leases	23,357	3,671	0
Share based compensation	31,934	26,259	22,866
Reserve for legal matters	2,020	657	0
Write-down of assets	3,239	1,216	428
Connectivity early termination	2,000	0	0
Tax receivable agreement obligation reduction	0	(86,599)	0
Deferred taxes	4,131	102,973	13,313
Gain on sale of businesses	(335,211)	0	0
Other	418	(4,577)	(1,070)
Changes in operating assets and liabilities:
Securities borrowed	71,488	155,277	233,291
Securities purchased under agreements to resell	(15,475)	16,894	14,981
Receivables from broker dealers and clearing organizations	(129,431)	26,145	27,808
Trading assets, at fair value	72,701	1,210,599	(530,668)
Other assets	125,272	44,494	772
Securities loaned	375,352	366,295	(302,400)
Securities sold under agreements to repurchase	(108,781)	(450,964)	0
Payables to broker dealers and clearing organizations	(148,764)	(516,376)	209,374
Trading liabilities, at fair value	90,797	(721,204)	370,065
Accounts payable and accrued expenses and other liabilities	(78,985)	17,860	(14,684)
Net cash provided by operating activities	714,595	290,574	239,599
Cash flows from investing activities
Development of capitalized software	(21,482)	(14,158)	(8,404)
Acquisition of property and equipment	(26,467)	(18,932)	(11,859)
Proceeds from sale of telecommunication assets	600	0	0
Investment in joint ventures	(23,669)	0	0
Investment in SBI Japannext	0	0	(38,754)
Acquisition of KCG Holdings, net of cash acquired, described in Note 3	0	(799,632)	0
Acquisition of Teza Technologies	0	(5,594)	0
Net cash provided by (used in) investing activities	329,174	(838,016)	(59,017)
Cash flows from financing activities
Distribution from Virtu Financial to non-controlling interest	(206,903)	(89,563)	(162,969)
Dividends	(100,329)	(63,814)	(37,759)
Repurchase of stock	(66,218)	(2,683)	(4,539)
Stock option exercised	76,754	0	0
Short-term borrowings, net	(15,000)	7,000	(20,000)
Proceeds from long-term borrowings	0	1,115,036	75,753
Repayment of long term borrowings	(500,000)	(256,473)	(3,825)
Repayment of KCG Notes	0	(480,987)	0
Tax receivable agreement obligations	(12,359)	(7,045)	0
Debt issuance costs	(2,261)	(56,505)	(5,094)
Issuance of common stock, net of offering costs	0	735,974	0
Issuance of common stock in connection with secondary offering, net of offering costs	(950)	0	16,677
Repurchase of Virtu Financial Units and corresponding number of Class C common stock in connection with secondary offering	0	0	(17,383)
Net cash provided by (used in) financing activities	(835,482)	889,797	(161,237)
Effect of exchange rate changes on cash and cash equivalents	(5,127)	9,117	(1,165)
Net increase (decrease) in cash and cash equivalents	203,160	351,472	18,180
Cash and cash equivalents beginning of period	532,887	181,415	163,235
Cash and cash equivalents, end of period	736,047	532,887	181,415
Supplementary disclosure of cash flow information
Cash paid for interest	139,412	112,982	54,872
Cash paid for taxes	93,991	5,976	16,175
Non-cash investing activities
Share based compensation to developers relating to capitalized software	2,936	1,605	2,750
Non-cash financing activities
Tax receivable agreement described in Note 6	(991)	1,534	545
Discount on issuance of senior secured credit facility	0	1,438	1,350
Secondary offerings described in Note 16	0	0	0
Class A-2 Interests
Cash flows from financing activities
Repurchase of stock	0	(11,143)	(2,000)
Class C common stock
Cash flows from financing activities
Repurchase of stock	(8,216)	0	(98)
BondPoint
Cash flows from investing activities
Proceeds from sale of business	400,192	0	0
DMM Business
Cash flows from investing activities
Proceeds from sale of business	$ 0	$ 300	$ 0