Segment Information - Components of Corporate/Other (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Interest income	$ 189,400	$ 128,305
Interest expense	(136,298)	(102,552)
Net Interest Income	53,102	25,753
Investment fair value changes, net	(6,120)	45,087
Other	230	1,571
Total non-interest income, net	18,759	134,253
General and administrative expenses	(34,854)	(43,551)
Loan acquisition costs	(4,465)	(3,559)
Other expenses	(4,085)	(4,096)
Net Income	30,915	97,257
Corporate/ Other
Segment Reporting Information [Line Items]
Interest income	1,020	1,362
Interest expense	(10,213)	(10,261)
Net Interest Income	(9,193)	(8,899)
Investment fair value changes, net	(714)	(674)
Other	126	147
Total non-interest income, net	(588)	(527)
General and administrative expenses	(15,148)	(17,504)
Loan acquisition costs	0	(4)
Other expenses	0	17
Net Income	(24,929)	(26,917)
Corporate/ Other | Legacy Consolidated VIEs
Segment Reporting Information [Line Items]
Interest income	1,012	1,348
Interest expense	(701)	(875)
Net Interest Income	311	473
Investment fair value changes, net	(714)	(699)
Other	0	0
Total non-interest income, net	(714)	(699)
General and administrative expenses	0	0
Loan acquisition costs	0	0
Other expenses	0	0
Net Income	(403)	(226)
Corporate/ Other | Other
Segment Reporting Information [Line Items]
Interest income	8	14
Interest expense	(9,512)	(9,386)
Net Interest Income	(9,504)	(9,372)
Investment fair value changes, net	0	25
Other	126	147
Total non-interest income, net	126	172
General and administrative expenses	(15,148)	(17,504)
Loan acquisition costs	0	(4)
Other expenses	0	17
Net Income	$ (24,526)	$ (26,691)