Commercial Loans - Components of the Carrying Value of Commercial Real Estate Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Commercial Loans, at Fair Value
Variable Interest Entity [Line Items]
Principal	$ 177,793	$ 177,797
Unamortized premium	0	0
Unamortized discount	0	0
Amortized cost	177,793	177,797
Gross unrealized gains	0	0
Gross unrealized losses	(63,770)	(61,587)
Fair value	114,023	116,210
CSMC USA Trust Securitized Commercial Loan, at Fair Value
Variable Interest Entity [Line Items]
Principal	1,385,591	1,385,591
Unamortized premium	0	0
Unamortized discount	(97,425)	(110,770)
Amortized cost	1,288,166	1,274,821
Gross unrealized gains	0	80,987
Gross unrealized losses	(44,795)	0
Fair value	1,243,371	1,355,808
RSBC Trust Commercial Loans, at Fair Value
Variable Interest Entity [Line Items]
Principal	14,362	14,362
Unamortized premium	0	0
Unamortized discount	0	0
Amortized cost	14,362	14,362
Gross unrealized gains	36	0
Gross unrealized losses	0	0
Fair value	$ 14,398	$ 14,362