Loans Receivable, Net - Net Book Value, Total Loan Exposure and Net Loan Exposure of Loans Receivable Based on Internal Risk Ratings (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) security_loan	Dec. 31, 2023 USD ($) loan	Dec. 31, 2022 USD ($) security_loan	Dec. 31, 2022 USD ($) loan	Dec. 31, 2021 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans		178	178	203	203
Net Book Value	$ 23,787,012	$ 23,787,012	$ 23,787,012	$ 25,017,880	$ 25,017,880	$ 22,003,017
CECL reserve	(576,936)	(576,936)	(576,936)	(326,137)	(326,137)	(124,679)
Loans receivable, net	23,210,076	23,210,076	23,210,076	24,691,743	24,691,743
Total Loan Exposure	24,971,028	24,971,028	24,971,028	26,810,281	26,810,281
Net Loan Exposure	21,951,988	21,951,988	21,951,988	23,659,183	23,659,183
Principal balance	23,923,719	23,923,719	23,923,719	25,160,343	25,160,343	$ 22,156,437
Total loan exposure including non-consolidated senior interests	1,100,000	1,100,000	1,100,000	1,600,000	1,600,000
Loan participations sold	337,721	337,721	337,721	224,744	224,744
Net loan exposure, asset-specific debt	1,000,000	1,000,000	1,000,000	950,300	950,300
Cost-recovery proceeds	52,978
Junior Loan Participation
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan participations sold	100,924	100,924	100,924
Senior Participations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan participations sold	236,797	236,797	$ 236,797	224,744	$ 224,744
1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan			15		17
Net Book Value	763,101	763,101	$ 763,101	1,403,185	$ 1,403,185
Total Loan Exposure	811,217	811,217	811,217	1,428,232	1,428,232
Net Loan Exposure	763,223	763,223	$ 763,223	1,170,725	$ 1,170,725
2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan			36		36
Net Book Value	6,143,184	6,143,184	$ 6,143,184	5,880,424	$ 5,880,424
Total Loan Exposure	6,618,319	6,618,319	6,618,319	6,562,852	6,562,852
Net Loan Exposure	5,095,395	5,095,395	$ 5,095,395	5,292,933	$ 5,292,933
3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan			99		134
Net Book Value	12,277,518	12,277,518	$ 12,277,518	14,128,133	$ 14,128,133
Total Loan Exposure	12,573,282	12,573,282	12,573,282	15,209,018	15,209,018
Net Loan Exposure	11,964,620	11,964,620	$ 11,964,620	13,826,730	$ 13,826,730
4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan			15		11
Net Book Value	2,725,930	2,725,930	$ 2,725,930	2,677,027	$ 2,677,027
Total Loan Exposure	3,036,837	3,036,837	3,036,837	2,680,145	2,680,145
Net Loan Exposure	2,668,025	2,668,025	$ 2,668,025	2,628,539	$ 2,628,539
5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan			13		5
Net Book Value	1,877,279	1,877,279	$ 1,877,279	929,111	$ 929,111
Total Loan Exposure	1,931,373	1,931,373	1,931,373	930,034	930,034
Net Loan Exposure	$ 1,460,725	$ 1,460,725	$ 1,460,725	$ 740,256	$ 740,256