Parent Company - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities
Net income	$ (103,705)	$ 620,192	$ 18,898
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred taxes	(18,691)	4,131	102,973
Other	880	418	(4,577)
Net cash provided by (used in) operating activities	168,771	714,595	290,574
Cash flows from investing activities
Net cash provided by (used in) investing activities	(899,643)	329,174	(838,016)
Cash flows from financing activities
Distribution from Virtu Financial to non-controlling interest	(99,221)	(206,903)	(89,563)
Dividends	(112,414)	(100,329)	(63,814)
Tax receivable agreement obligations	0	(12,359)	(7,045)
Issuance of common stock, net of offering costs	0	0	735,974
Net cash provided by (used in) financing activities	769,580	(835,482)	889,797
Net increase (decrease) in cash and cash equivalents	37,233	203,160	351,472
Cash, cash equivalents, and restricted or segregated cash, beginning of period	736,047	532,887	181,415
Cash, cash equivalents, and restricted or segregated cash, end of period	773,280	736,047	532,887
Supplemental disclosure of cash flow information:
Taxes paid	12,273	93,991	5,976
Non-cash financing activities
Tax receivable agreement described in Note 6	0	(991)	1,534
Treasury Stock
Cash flows from financing activities
Purchase of treasury stock	(15,878)	(66,218)	(2,683)
Class C common stock
Cash flows from financing activities
Purchase of treasury stock	(196)	(8,216)	0
VFH
Cash flows from operating activities
Net income	(29,419)	620,192	2,939
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in income of subsidiary, net of tax	136,878	(305,936)	(513,601)
Tax receivable agreement obligation reduction	54,879	79,722	(86,599)
Deferred taxes	(8,165)	(64,996)	102,973
Other	0	0	(8,500)
Changes in operating assets and liabilities:	2,339	(25,268)	(8,832)
Net cash provided by (used in) operating activities	156,512	303,714	(511,620)
Cash flows from investing activities
Acquisition of KCG, net of cash acquired, described in Note 3	0	0	(23,908)
Investments in subsidiaries, equity basis	70,762	34,909	16,846
Net cash provided by (used in) investing activities	70,762	34,909	(7,062)
Cash flows from financing activities
Distribution from Virtu Financial to non-controlling interest	(99,221)	(206,903)	(89,563)
Dividends	(112,414)	(100,329)	(63,814)
Payments on repurchase of non-voting common interest	0	0	(11,143)
Tax receivable agreement obligations	0	(12,359)	(7,045)
Issuance of common stock, net of offering costs	0	0	735,974
Issuance of common stock in connection with secondary offering, net of offering costs	(375)	(950)	0
Net cash provided by (used in) financing activities	(226,465)	(394,975)	561,726
Net increase (decrease) in cash and cash equivalents	809	(56,352)	43,044
Cash, cash equivalents, and restricted or segregated cash, beginning of period	3,841	60,193	17,149
Cash, cash equivalents, and restricted or segregated cash, end of period	4,650	3,841	60,193
Supplemental disclosure of cash flow information:
Taxes paid	0	0	133
Non-cash financing activities
Tax receivable agreement described in Note 6	0	0	1,534
VFH | Treasury Stock
Cash flows from financing activities
Purchase of treasury stock	(14,259)	(66,218)	(2,683)
VFH | Class C common stock
Cash flows from financing activities
Repurchase of Class C common stock	$ (196)	$ (8,216)	$ 0