Investments - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Mar. 31, 2021	May 31, 2019	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019	Jan. 31, 2020	Jul. 01, 2019	Aug. 11, 2018	Aug. 02, 2018
Schedule of Equity Method Investments [Line Items]
Equity in income of investees			$ 32,389	$ 20,731	$ 7,457
Other investments	$ 17,381		17,381	13,394
Cash received on transfer of other investments		$ 15,750	0	15,750	0
Secured financing	17,381		17,381	13,394
Amortized cost	9,902		9,902
Unrealized gain on investments			7,281		705
Unrealized loss on investments				(748)
Recognized gain (loss) on secured financing liability			(7,281)	43
Equity securities without readily determinable fair value, amount	109,821		109,821	17,091	2,990
Distributions received from investments valued under the measurement alternative			3,072
Fair value adjustment						$ 1,507
Proceeds from sales of investments valued under the measurement alternative				6,419	22,531
Impairment of equity securities					701
Strategic Partnership
Schedule of Equity Method Investments [Line Items]
Equity securities without readily determinable fair value, amount	90,000		90,000
Distributions received from investments valued under the measurement alternative	$ 3,072
Investment, Measurement Alternative
Schedule of Equity Method Investments [Line Items]
Net gain (loss) on other investments			$ 6,229
Manual Data Entry Software
Schedule of Equity Method Investments [Line Items]
Equity securities without readily determinable fair value, amount				2,000
Alternative Asset Investment Platform
Schedule of Equity Method Investments [Line Items]
Equity securities without readily determinable fair value, amount				10,000
Equity Securities sold July 1, 2019
Schedule of Equity Method Investments [Line Items]
Equity securities without readily determinable fair value, amount							$ 1,446
Proceeds from sales of investments valued under the measurement alternative				6,419
Gain on sale of investment				4,973
Equity securities sold August, 2 2018
Schedule of Equity Method Investments [Line Items]
Equity securities without readily determinable fair value, amount									$ 10,798
Proceeds from sales of investments valued under the measurement alternative					17,724
Gain on sale of investment					6,926
Equity securities sold August 11, 2018
Schedule of Equity Method Investments [Line Items]
Equity securities without readily determinable fair value, amount								$ 600
Proceeds from sales of investments valued under the measurement alternative					4,807
Gain on sale of investment					4,207
Partnerships
Schedule of Equity Method Investments [Line Items]
Percent interest in partnerships	1.00%		1.00%
Equity in income of investees			$ 32,389	$ 20,731	$ 7,457
Direct Equity Co-Investments, Special Purpose Vehicle
Schedule of Equity Method Investments [Line Items]
Other investments	$ 4,083		$ 4,083