Fair Values - Schedule of Details of Book Value, Face Amount, and Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Financial assets
Cash and cash equivalents, book value	$ 388,049	$ 323,483
Cash and cash equivalents, fair value	388,049	323,483
Loans receivable, net, book value	18,965,254	18,313,582
Loan receivable, net, face amount	19,874,340	19,203,126
Loan receivable, net, fair value	18,942,580	18,288,958
Financial liabilities
Long-term debt, face amount	14,035,684
Loan participations sold, net, book value	50,000	100,064
Loan participations sold, net, face amount	50,000	100,064
Loan participations sold, net, fair value	50,000	99,822
Secured debt, net
Financial liabilities
Long-term debt	10,683,320	9,696,334
Long-term debt, face amount	10,693,596	9,705,529
Long-term debt, fair value	10,568,791	9,590,400
Securitized debt obligations, net
Financial liabilities
Long-term debt	2,493,011	1,936,956
Long-term debt, face amount	2,502,834	1,936,967
Long-term debt, fair value	2,464,198	1,838,089
Asset-specific debt, net
Financial liabilities
Long-term debt	528,224	1,224,841
Long-term debt, face amount	529,867	1,228,110
Long-term debt, fair value	519,637	1,218,639
Secured term loans, net
Financial liabilities
Long-term debt	1,726,444	1,732,073
Long-term debt, face amount	1,760,748	1,764,437
Long-term debt, fair value	1,761,199	1,765,668
Senior secured notes, net
Financial liabilities
Long-term debt	784,066	771,035
Long-term debt, face amount	785,316	785,316
Long-term debt, fair value	803,996	780,931
Convertible notes, net
Financial liabilities
Long-term debt	264,181	263,616
Long-term debt, face amount	266,157	266,157
Long-term debt, fair value	$ 260,996	$ 257,707