SEC Schedule, Article 12-29, Mortgage Loans on Real Estate (Rollforward) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2019
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Beginning Balance		$ 1,400,100	$ 692,131
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, New Mortgage Loan	$ 716,241	1,949,449	837,502
Net unrealized gain	11,427	0	6,717
Net realized gain	0	0	3,878
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Cost of Mortgage Sold	28,613	145,755	28,805
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Collections of Principal	496,186	812,988	275,520
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Amortization of Premium	6,317	13,754	6,363
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Foreclosure	3,384	14,033	22,578
Net unrealized loss	0	119	0
Net realized loss	30	20,475	0
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Ending Balance	$ 1,400,100	$ 2,342,425	$ 1,206,962