Regulatory Requirement - Narrative (Details)	9 Months Ended
	Sep. 30, 2019 USD ($) broker_dealer
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Number of broker-dealer subsidiaries | broker_dealer	5
Virtu Financial Capital Markets LLC
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Minimum capital required to be maintained in connection with the operation of the Company's DMM business	$ 1,000,000.0
Required amount under exchange rules	1,000,000
Required amount under exchange rules for every 0.1% NYSE transaction dollar volume	$ 75,000
Percentage of NYSE transaction dollar volume	0.10%
VAL
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cash in special reserve bank accounts for the benefit of customers	$ 2,000,000.0
Cash in reserve bank accounts for the benefit of proprietary accounts of brokers	2,500,000
VITG
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cash in special reserve bank accounts for the benefit of customers	7,400,000
Cash in reserve bank accounts for the benefit of proprietary accounts of brokers	$ 5,400,000