Investments - Equity Method Investments Roll forward (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Carrying amount beginning of the year	$ 168,732	$ 156,100
Purchases	1,177	20,236
Sales / return of capital	(178)	0
Net unrealized loss gain	1,177	6,687
Net realized (loss) gain	(522)	0
Carrying amount, end of year	$ 170,386	$ 183,023