Schedule IV - Mortgage Loans on Real Estate - Loan Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Activity in loan portfolio
Balance at the beginning of the period	$ 12,139,908	$ 11,470,224	$ 9,794,254
Acquisitions/originations/additional funding	13,990,579	5,337,399	9,094,714
Capitalized Interest	119,136	144,013	110,632
Basis of loans sold	(4,176,868)	(3,307,003)	(4,311,390)
Loan maturities/principal repayments	(4,197,809)	(1,821,196)	(3,304,838)
Discount accretion/premium amortization	57,948	42,199	35,387
Change in fair value of mortgage loans, net	69,050	133,124	71,601
Foreign currency translation, net	(72,130)	102,553	40,155
Credit loss reversal (provision), net	(4,633)	(46,091)	(7,126)
Transfer to/from other asset classifications or between segments	524,776	105,126	(25,862)
Balance at the end of the period	18,413,649	12,139,908	11,470,224
Commercial and Residential Lending Segment and Investing and Servicing Segment
Activity in loan portfolio
Balance at the beginning of the period	10,584,400	9,890,693	7,806,699
Acquisitions/originations/additional funding	13,173,459	5,058,705	8,174,321
Capitalized Interest	118,273	143,023	109,978
Basis of loans sold	(4,139,166)	(3,246,515)	(3,921,171)
Loan maturities/principal repayments	(3,709,444)	(1,590,379)	(2,387,843)
Discount accretion/premium amortization	51,816	38,942	29,775
Change in fair value of mortgage loans, net	69,050	133,124	71,601
Foreign currency translation, net	(71,419)	102,748	38,050
Credit loss reversal (provision), net	7,947	(40,955)	(2,616)
Loan foreclosures and other transfers	(36,308)	(71,488)	(27,303)
Transfer to/from other asset classifications or between segments	320,191	176,614	(798)
Balance at the end of the period	$ 16,368,799	10,584,400	9,890,693
Cumulative Effect, Period of Adoption, Adjustment
Activity in loan portfolio
Balance at the beginning of the period		(20,440)
Balance at the end of the period			(20,440)
Cumulative Effect, Period of Adoption, Adjustment | Commercial and Residential Lending Segment and Investing and Servicing Segment
Activity in loan portfolio
Balance at the beginning of the period		$ (10,112)
Balance at the end of the period			$ (10,112)