Loans - Risk Ratings by Class of Loan (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Investments in loans
Total Amortized Cost Basis	$ 20,528,925	$ 21,285,446
Credit Loss Allowance	309,039	99,413
Loans under fair value option
Investments in loans
Total Amortized Cost Basis	2,645,637	$ 2,784,594
Credit Loss Allowance	0
Commercial Portfolio Segment
Investments in loans
2023	915,656
2022	4,123,106
2021	6,985,760
2020	737,416
2019	1,456,090
Prior	1,159,336
Revolving Loans Amortized Cost Total	0
Total Amortized Cost Basis	15,377,364
Credit Loss Allowance	298,775
Commercial Portfolio Segment | LTV less than 60%
Investments in loans
2023	321,465
2022	2,040,870
2021	2,979,413
2020	188,140
2019	937,355
Prior	232,009
Revolving Loans Amortized Cost Total	0
Total Amortized Cost Basis	6,699,252
Credit Loss Allowance	24,939
Commercial Portfolio Segment | LTV 60% - 70%
Investments in loans
2023	518,912
2022	1,937,799
2021	3,522,841
2020	97,805
2019	85,287
Prior	318,432
Revolving Loans Amortized Cost Total	0
Total Amortized Cost Basis	6,481,076
Credit Loss Allowance	78,495
Commercial Portfolio Segment | LTV > 70%
Investments in loans
2023	60,905
2022	102,732
2021	483,506
2020	451,471
2019	433,448
Prior	589,037
Revolving Loans Amortized Cost Total	0
Total Amortized Cost Basis	2,121,099
Credit Loss Allowance	190,416
Commercial Portfolio Segment | Credit deteriorated
Investments in loans
2023	0
2022	0
2021	0
2020	0
2019	0
Prior	4,925
Revolving Loans Amortized Cost Total	0
Total Amortized Cost Basis	4,925
Credit Loss Allowance	4,925
Commercial Portfolio Segment | Defeased and other
Investments in loans
2023	14,374
2022	41,705
2021	0
2020	0
2019	0
Prior	14,933
Revolving Loans Amortized Cost Total	0
Total Amortized Cost Basis	71,012
Credit Loss Allowance	0
Infrastructure Portfolio Segment
Investments in loans
2023	900,990
2022	136,704
2021	317,479
2020	72,687
2019	494,924
Prior	577,859
Revolving Loans Amortized Cost Total	5,281
Total Amortized Cost Basis	2,505,924
Credit Loss Allowance	10,264
Infrastructure Portfolio Segment | Power
Investments in loans
2023	441,646
2022	0
2021	106,343
2020	72,687
2019	276,795
Prior	442,784
Revolving Loans Amortized Cost Total	3,213
Total Amortized Cost Basis	1,343,468
Credit Loss Allowance	4,099
Infrastructure Portfolio Segment | Oil and gas
Investments in loans
2023	410,674
2022	136,704
2021	211,136
2020	0
2019	218,129
Prior	135,075
Revolving Loans Amortized Cost Total	2,068
Total Amortized Cost Basis	1,113,786
Credit Loss Allowance	6,009
Infrastructure Portfolio Segment | Other
Investments in loans
2023	48,670
2022	0
2021	0
2020	0
2019	0
Prior	0
Revolving Loans Amortized Cost Total	0
Total Amortized Cost Basis	48,670
Credit Loss Allowance	$ 156