Parent Company - Condensed Statements of Financial Condition (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2018	May 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Deferred tax assets	$ 200,359		$ 125,760
Other assets	254,149		357,352
Total assets	7,380,978		7,320,006
Liabilities
Accounts payable and accrued expenses and other liabilities	294,975		358,825
Tax receivable agreement obligations	214,403	$ 79,700	147,040
Total liabilities	5,886,279		6,168,428
Virtu Financial Inc. Stockholders' equity
Treasury stock, at cost, 616,923 and 453,066 shares at December 31, 2017 and 2016, respectively	(55,005)		(11,041)
Additional paid-in capital	1,010,468		900,746
Accumulated deficit	96,513		(62,129)
Accumulated other comprehensive income (loss)	(82)		2,991
Total Virtu Financial Inc. stockholders' equity	1,051,896		830,569
Total liabilities and equity	$ 7,380,978		$ 7,320,006
Treasury stock, shares (in shares)	2,178,771		616,923
Class A
Virtu Financial Inc. Stockholders' equity
Common stock	$ 1		$ 1
Common stock, par value (in dollars per share)	$ 0.00001		$ 0.00001
Common stock, shares authorized (in shares)	1,000,000,000		1,000,000,000
Common stock, shares issued (in shares)	108,955,048		90,415,532
Common stock, shares outstanding (in shares)	106,776,277		89,798,609
Class B
Virtu Financial Inc. Stockholders' equity
Common stock	$ 0		$ 0
Common stock, par value (in dollars per share)	$ 0.00001		$ 0.00001
Common stock, shares authorized (in shares)	175,000,000		175,000,000
Common stock, shares issued (in shares)	0		0
Common stock, shares outstanding (in shares)	0		0
Class C
Virtu Financial Inc. Stockholders' equity
Common stock	$ 0		$ 0
Common stock, par value (in dollars per share)	$ 0.00001		$ 0.00001
Common stock, shares authorized (in shares)	90,000,000		90,000,000
Common stock, shares issued (in shares)	13,749,886		17,880,239
Common stock, shares outstanding (in shares)	13,749,886		17,880,239
Class D
Virtu Financial Inc. Stockholders' equity
Common stock	$ 1		$ 1
Common stock, par value (in dollars per share)	$ 0.00001		$ 0.00001
Common stock, shares authorized (in shares)	175,000,000		175,000,000
Common stock, shares issued (in shares)	69,091,740		79,610,490
Common stock, shares outstanding (in shares)	69,091,740		79,610,490
VFH
Assets
Cash	$ 3,841		$ 60,193	$ 17,149	$ 187
Deferred tax assets	189,627		124,631
Investment in subsidiary	1,730,867		1,549,162
Other assets	35,998		10,731
Total assets	1,960,333		1,744,717
Liabilities
Payable to affiliate	694,028		767,101
Accounts payable and accrued expenses and other liabilities	6		7
Tax receivable agreement obligations	214,403		147,040
Total liabilities	908,437		914,148
Virtu Financial Inc. Stockholders' equity
Treasury stock, at cost, 616,923 and 453,066 shares at December 31, 2017 and 2016, respectively	(55,005)		(11,041)
Additional paid-in capital	1,010,468		900,746
Accumulated deficit	96,513		(62,129)
Accumulated other comprehensive income (loss)	(82)		2,991
Total Virtu Financial Inc. stockholders' equity	1,051,896		830,569
Total liabilities and equity	$ 1,960,333		$ 1,744,717
Treasury stock, shares (in shares)	616,923		453,066
VFH | Class A-1
Virtu Financial Inc. Stockholders' equity
Common stock	$ 0		$ 0
Common stock, shares authorized (in shares)	0		0
Common stock, shares issued (in shares)	0		0
Common stock, shares outstanding (in shares)	0		0
VFH | Class A-2
Virtu Financial Inc. Stockholders' equity
Common stock	$ 0		$ 0
Common stock, shares authorized (in shares)	0		0
Common stock, shares issued (in shares)	0		0
Common stock, shares outstanding (in shares)	0		0
VFH | Class A
Virtu Financial Inc. Stockholders' equity
Common stock	$ 1		$ 1
Common stock, par value (in dollars per share)	$ 0.00001		$ 0.00001
Common stock, shares authorized (in shares)	1,000,000,000		1,000,000,000
Common stock, shares issued (in shares)	90,415,532		40,436,580
Common stock, shares outstanding (in shares)	89,798,609		39,983,514
VFH | Class B
Virtu Financial Inc. Stockholders' equity
Common stock	$ 0		$ 0
Common stock, par value (in dollars per share)	$ 0.00001		$ 0.00001
Common stock, shares authorized (in shares)	175,000,000		175,000,000
Common stock, shares issued (in shares)	0		0
Common stock, shares outstanding (in shares)	0		0
VFH | Class C
Virtu Financial Inc. Stockholders' equity
Common stock	$ 0		$ 0
Common stock, par value (in dollars per share)	$ 0.00001		$ 0.00001
Common stock, shares authorized (in shares)	90,000,000		90,000,000
Common stock, shares issued (in shares)	17,880,239		19,810,707
Common stock, shares outstanding (in shares)	17,880,239		19,810,707
VFH | Class D
Virtu Financial Inc. Stockholders' equity
Common stock	$ 1		$ 1
Common stock, par value (in dollars per share)	$ 0.00001		$ 0.00001
Common stock, shares authorized (in shares)	175,000,000		175,000,000
Common stock, shares issued (in shares)	79,610,490		79,610,490
Common stock, shares outstanding (in shares)	79,610,490		79,610,490