Mortgage-Backed Securities - Unrealized Gain (Loss) on Investments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Investments [Line Items]
Unrealized gain (loss) on investments, net	$ 488	$ (65,103)	$ 57,609	$ (176,354)
Residential Mortgage Backed Securities [Member]
Investments [Line Items]
Debt Securities, Trading, Unrealized Gain (Loss)	1,254	(64,398)	57,033	(174,599)
Commercial Mortgage Backed Securities [Member]
Investments [Line Items]
Debt Securities, Trading, Unrealized Gain (Loss)	(275)	0	(37)	0
Interest-Only-Strip [Member]
Investments [Line Items]
Debt Securities, Trading, Unrealized Gain (Loss)	(466)	(711)	626	(1,841)
Asset-backed Securities, Securitized Loans and Receivables
Investments [Line Items]
Unrealized gain (loss) on other investments	$ (25)	$ 6	$ (13)	$ 86