Loans Receivable, Net - Net Book Value, Total Loan Exposure and Net Loan Exposure of Loans Receivable Based on Internal Risk Ratings (Detail) $ in Thousands	Mar. 31, 2023 USD ($) SecurityLoan	Dec. 31, 2022 USD ($) SecurityLoan	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	199	203
Net Book Value	$ 24,896,364	$ 25,017,880
CECL reserve	(336,591)	(326,137)	$ (122,221)	$ (124,679)
Loans receivable, net	24,559,773	24,691,743
Total Loan Exposure	26,742,669	26,810,281
Net Loan Exposure	23,631,557	23,659,183
Total loan exposure including non-consolidated senior interests	1,700,000	1,600,000
Net loan exposure, asset-specific debt	822,900	950,300
Net loan exposure, loan participations sold	$ 229,500	$ 224,700
1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	17	17
Net Book Value	$ 1,158,445	$ 1,403,185
Total Loan Exposure	1,182,278	1,428,232
Net Loan Exposure	$ 1,128,313	$ 1,170,725
2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	40	36
Net Book Value	$ 6,462,458	$ 5,880,424
Total Loan Exposure	7,689,868	6,562,852
Net Loan Exposure	$ 5,808,391	$ 5,292,933
3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	123	134
Net Book Value	$ 13,105,735	$ 14,128,133
Total Loan Exposure	13,695,326	15,209,018
Net Loan Exposure	$ 12,775,551	$ 13,826,730
4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	13	11
Net Book Value	$ 3,172,029	$ 2,677,027
Total Loan Exposure	3,177,140	2,680,145
Net Loan Exposure	$ 3,118,503	$ 2,628,539
5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	6	5
Net Book Value	$ 997,697	$ 929,111
Total Loan Exposure	998,057	930,034
Net Loan Exposure	$ 800,799	$ 740,256