Loans - Activity in Portfolio (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	May 31, 2023 USD ($)	Sep. 30, 2023 USD ($) power_plant	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) power_plant	Sep. 30, 2022 USD ($)
Activity in allowance for loan losses
Credit loss allowance at beginning of the period				$ 99,413
Credit loss provision, net				197,675	$ 25,341
Credit loss allowance at the end of the period		$ 271,320		$ 271,320
Number of natural gas power plant | power_plant		2		2
Activity in loan portfolio
Balance at the beginning of the period				$ 21,186,033	18,413,649
Acquisitions/originations/additional funding				2,022,544	8,800,865
Capitalized Interest				92,202	87,674
Basis of loans sold				(390,321)	(4,062,841)
Loan maturities/principal repayments				(2,723,990)	(1,957,881)
Discount accretion/premium amortization				51,031	47,468
Changes in fair value		$ (66,806)	$ (87,474)	(111,247)	(326,737)
Foreign currency translation loss, net				(50,107)	(617,199)
Credit loss provision, net				(197,675)	(25,341)
Loan foreclosure				(42,000)	(50,151)
Transfer to/from other asset classifications or between segments				0	0
Balance at the end of the period		19,836,470	20,309,506	19,836,470	20,309,506
Loan foreclosure				42,000	50,151
Funded Commitments
Activity in allowance for loan losses
Credit loss allowance at beginning of the period				99,413
Credit loss provision, net				197,675
Charge-offs				(25,768)
Credit loss allowance at the end of the period		271,320		271,320
Activity in loan portfolio
Credit loss provision, net				(197,675)
Unfunded commitments
Activity in allowance for loan losses
Credit loss allowance at beginning of the period				9,873
Credit loss provision, net				10,266
Credit loss allowance at the end of the period		20,139		20,139
Unfunded commitments		1,462,086		1,462,086
Activity in loan portfolio
Credit loss provision, net				(10,266)
HTM Preferred Intrests
Activity in allowance for loan losses
Credit loss allowance at beginning of the period				0
Credit loss provision, net				6,695
Credit loss allowance at the end of the period		6,695		6,695
Unfunded commitments		19,543		19,543
Activity in loan portfolio
Credit loss provision, net				(6,695)
CMBS
Activity in allowance for loan losses
Credit loss allowance at beginning of the period				52
Credit loss provision, net				88
Credit loss allowance at the end of the period		140		140
Unfunded commitments		33,806		33,806
Activity in loan portfolio
Credit loss provision, net				(88)
Total loans held-for-investment
Activity in allowance for loan losses
Credit loss allowance at beginning of the period				99,413
Credit loss allowance at the end of the period		271,320		271,320
Loans under fair value option
Activity in allowance for loan losses
Credit loss provision, net				0	0
Credit loss allowance at the end of the period		0		0
Activity in loan portfolio
Balance at the beginning of the period				2,784,594	2,876,800
Acquisitions/originations/additional funding				363,520	3,793,467
Capitalized Interest				172	402
Basis of loans sold				(337,321)	(4,056,511)
Loan maturities/principal repayments				(137,916)	(146,184)
Discount accretion/premium amortization				0	0
Changes in fair value				(111,247)	(326,252)
Foreign currency translation loss, net				0	0
Credit loss provision, net				0	0
Loan foreclosure				(929)	0
Transfer to/from other asset classifications or between segments				41,392	63,962
Balance at the end of the period		2,602,265	2,205,684	2,602,265	2,205,684
Loan foreclosure				929	0
Commercial Portfolio Segment
Activity in allowance for loan losses
Credit loss allowance at the end of the period		261,914		261,914
Commercial Portfolio Segment | Credit deteriorated
Activity in allowance for loan losses
Credit loss allowance at the end of the period		4,925		4,925
Commercial Portfolio Segment | Senior Loans | Chicago
Activity in loan portfolio
Loan foreclosure	$ (41,100)
Loan foreclosure	$ 41,100
Commercial Portfolio Segment | Funded Commitments
Activity in allowance for loan losses
Credit loss allowance at beginning of the period				88,801
Credit loss provision, net				187,775
Charge-offs				(14,662)
Credit loss allowance at the end of the period		261,914		261,914
Activity in loan portfolio
Credit loss provision, net				(187,775)
Commercial Portfolio Segment | Loans Held-For-Investment
Activity in allowance for loan losses
Credit loss allowance at beginning of the period				9,749
Credit loss provision, net				3,141
Credit loss allowance at the end of the period		12,890		12,890
Unfunded commitments		1,362,554		1,362,554
Activity in loan portfolio
Credit loss provision, net				(3,141)
Commercial Portfolio Segment | Total loans held-for-investment
Activity in allowance for loan losses
Credit loss allowance at beginning of the period				88,801
Credit loss provision, net				187,775	18,262
Credit loss allowance at the end of the period		261,914		261,914
Activity in loan portfolio
Balance at the beginning of the period				16,048,507	13,450,198
Acquisitions/originations/additional funding				1,053,627	4,410,306
Capitalized Interest				91,641	85,454
Basis of loans sold				(53,000)	(6,330)
Loan maturities/principal repayments				(1,903,021)	(1,558,907)
Discount accretion/premium amortization				40,733	40,179
Changes in fair value				0	0
Foreign currency translation loss, net				(48,362)	(612,669)
Credit loss provision, net				(187,775)	(18,262)
Loan foreclosure				(41,071)	(50,151)
Transfer to/from other asset classifications or between segments				(41,392)	(63,616)
Balance at the end of the period		14,959,887	15,676,202	14,959,887	15,676,202
Loan foreclosure				41,071	50,151
Infrastructure Portfolio Segment
Activity in allowance for loan losses
Credit loss allowance at the end of the period		9,406		9,406
Infrastructure Portfolio Segment | Credit deteriorated
Activity in allowance for loan losses
Credit loss allowance at the end of the period		0		0
Infrastructure Portfolio Segment | Infrastructure Loans | Chicago | Credit deteriorated
Activity in allowance for loan losses
Credit loss allowance at beginning of the period		11,100
Charge-offs				(11,100)
Infrastructure Portfolio Segment | Funded Commitments
Activity in allowance for loan losses
Credit loss allowance at beginning of the period				10,612
Credit loss provision, net				9,900
Charge-offs				(11,106)
Credit loss allowance at the end of the period		9,406		9,406
Activity in loan portfolio
Credit loss provision, net				(9,900)
Infrastructure Portfolio Segment | Loans Held-For-Investment
Activity in allowance for loan losses
Credit loss allowance at beginning of the period				72
Credit loss provision, net				342
Credit loss allowance at the end of the period		414		414
Unfunded commitments		46,183		46,183
Activity in loan portfolio
Credit loss provision, net				(342)
Infrastructure Portfolio Segment | Total loans held-for-investment
Activity in allowance for loan losses
Credit loss allowance at beginning of the period				10,612
Credit loss provision, net				9,900	7,079
Credit loss allowance at the end of the period		9,406		9,406
Activity in loan portfolio
Balance at the beginning of the period				2,352,932	2,027,426
Acquisitions/originations/additional funding				605,397	597,092
Capitalized Interest				389	373
Basis of loans sold				0	0
Loan maturities/principal repayments				(683,053)	(246,127)
Discount accretion/premium amortization				10,298	7,289
Changes in fair value				0	0
Foreign currency translation loss, net				(1,745)	(4,530)
Credit loss provision, net				(9,900)	(7,079)
Loan foreclosure				0	0
Transfer to/from other asset classifications or between segments				0	0
Balance at the end of the period		2,274,318	2,374,444	2,274,318	2,374,444
Loan foreclosure				0	0
Residential Portfolio Segment | Residential Loans
Activity in loan portfolio
Loan foreclosure				(900)
Loan foreclosure				900
Residential Portfolio Segment | Total loans held-for-investment
Activity in allowance for loan losses
Credit loss provision, net				0	0
Activity in loan portfolio
Balance at the beginning of the period				0	59,225
Acquisitions/originations/additional funding				0	0
Capitalized Interest				0	1,445
Basis of loans sold				0	0
Loan maturities/principal repayments				0	(6,663)
Discount accretion/premium amortization				0	0
Changes in fair value				0	(485)
Foreign currency translation loss, net				0	0
Credit loss provision, net				0	0
Loan foreclosure				0	0
Transfer to/from other asset classifications or between segments				0	(346)
Balance at the end of the period		$ 0	$ 53,176	0	53,176
Loan foreclosure				$ 0	$ 0