Fair Values - Schedule of Details of Book Value, Face Amount, and Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Financial assets
Cash and cash equivalents, book value	$ 668,563	$ 323,483
Cash and cash equivalents, fair value	668,563	323,483
Loans receivable, net, book value	18,308,171	18,313,582
Loan receivable, net, face amount	19,217,768	19,203,126
Loan receivable, net, fair value	18,307,872	18,288,958
Financial liabilities
Long-term debt, face amount	13,317,843
Loan participations sold, net, book value	101,672	100,064
Loan participations sold, net, face amount	101,672	100,064
Loan participations sold, net, fair value	101,672	99,822
Secured debt, net
Financial liabilities
Long-term debt	10,000,027	9,696,334
Long-term debt, face amount	10,011,541	9,705,529
Long-term debt, fair value	9,907,858	9,590,400
Securitized debt obligations, net
Financial liabilities
Long-term debt	2,559,896	1,936,956
Long-term debt, face amount	2,569,979	1,936,967
Long-term debt, fair value	2,528,813	1,838,089
Asset-specific debt, net
Financial liabilities
Long-term debt	492,235	1,224,841
Long-term debt, face amount	494,081	1,228,110
Long-term debt, fair value	484,126	1,218,639
Secured term loans, net
Financial liabilities
Long-term debt	1,730,565	1,732,073
Long-term debt, face amount	1,760,748	1,764,437
Long-term debt, fair value	1,751,330	1,765,668
Senior secured notes, net
Financial liabilities
Long-term debt	779,187	771,035
Long-term debt, face amount	785,316	785,316
Long-term debt, fair value	780,725	780,931
Convertible notes, net
Financial liabilities
Long-term debt	263,898	263,616
Long-term debt, face amount	266,157	266,157
Long-term debt, fair value	$ 260,166	$ 257,707