Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2017
Financial Designation, Predecessor and Successor [Fixed List]	Successor	Predecessor	Successor	Predecessor
Net income attributable to Tradeweb Markets			$ 83,769
Foreign currency translation adjustments attributable to non-controlling interests			1,441
Total comprehensive income		$ 127,096	85,210	$ 86,533
Net income attributable to non-controlling interests			46,903
Foreign currency translation adjustments attributable to noncontrolling interests			298
Comprehensive income attributable to non-controlling interests			47,201
Tradeweb Markets LLC
Financial Designation, Predecessor and Successor [Fixed List]	Successor
Net income attributable to Tradeweb Markets	$ 29,307	130,160	42,352	83,648
Foreign currency translation adjustments attributable to non-controlling interests	(866)	(3,064)	988	2,885
Total comprehensive income	$ 28,441	$ 127,096	$ 43,340	$ 86,533