Fair Values - Schedule of Details of Book Value, Face Amount, and Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Financial assets
Cash and cash equivalents, book value	$ 323,483	$ 350,014
Cash and cash equivalents, fair value	323,483	350,014
Loans receivable, net, book value	18,313,582	23,210,076
Loan receivable, net, face amount	19,203,126	23,923,719	$ 25,160,343
Loan receivable, net, fair value	18,288,958	23,015,737
Financial liabilities
Long-term debt, face amount	13,749,549
Loan participations sold, net, book value	100,064	337,179
Loan participations sold, net, face amount	100,064	337,721
Loan participations sold, net, fair value	99,822	333,745
Secured debt, net
Financial liabilities
Long-term debt	9,696,334	12,683,095
Long-term debt, face amount	9,705,529	12,697,058
Long-term debt, fair value	9,590,400	12,425,609
Securitized debt obligations, net
Financial liabilities
Long-term debt	1,936,956	2,505,417
Long-term debt, face amount	1,936,967	2,507,514
Long-term debt, fair value	1,838,089	2,323,441
Asset-specific debt, net
Financial liabilities
Long-term debt	1,224,841	1,000,210
Long-term debt, face amount	1,228,110	1,004,097
Long-term debt, fair value	1,218,639	992,357
Secured term loans, net
Financial liabilities
Long-term debt	1,732,073	2,101,632
Long-term debt, face amount	1,764,437	2,135,221
Long-term debt, fair value	1,765,668	2,102,950
Senior secured notes, net
Financial liabilities
Long-term debt	771,035	362,763
Long-term debt, face amount	785,316	366,090
Long-term debt, fair value	780,931	327,081
Convertible notes, net
Financial liabilities
Long-term debt	263,616	295,847
Long-term debt, face amount	266,157	300,000
Long-term debt, fair value	$ 257,707	$ 272,076