Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income/(loss)	$ (22,255)	$ 18,806
Other comprehensive income/(loss), net of tax:
Foreign currency translation adjustment	(672)	215
Comprehensive income/(loss)	(22,927)	19,021
Comprehensive loss applicable to noncontrolling interests	(7,528)	(616)
Comprehensive income/(loss) applicable to Piper Sandler Companies	$ (15,399)	$ 19,637