Earnings Per Share - Reconciliation (Details) - USD ($) $ in Thousands	4 Months Ended	9 Months Ended	12 Months Ended
	Apr. 15, 2015	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of net income before minority interest to net income available for common stockholders
Income before income taxes and non-controlling interest			$ 113,164	$ 179,591	$ 215,929
Provision for (benefit from) income taxes			94,266	21,251	18,439
Net income (loss)	$ 83,147	$ 114,343	18,898	158,340	197,490
Net income allocable to members of Virtu Financial (for the period January 1, 2015 through April 15, 2015)	$ (83,147)
Noncontrolling interest		$ (93,456)	(15,959)	(125,360)	(176,603)
Net income available for common stockholders			$ 2,939	$ 32,980	$ 20,887