Variable Interest Entities - Summary of Assets and Liabilities of Consolidated VIE (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Assets:
Loans receivable	$ 24,831,546		$ 22,003,017
Current expected credit loss reserve	(133,024)	$ (122,221)	(124,679)	$ (128,945)	$ (172,100)	$ (173,549)
Loans receivable, net	24,698,522		21,878,338
Other assets	461,145		273,797
Assets	25,443,247		22,703,289
Liabilities:
Securitized debt obligations, net	2,841,901		2,838,062
Other liabilities	229,021		231,358
Liabilities	20,780,260		18,084,578
VIE
Assets:
Loans receivable	3,449,500		3,486,750
Current expected credit loss reserve	(5,950)		(4,502)
Loans receivable, net	3,443,550		3,482,248
Other assets	59,745		20,746
Assets	3,503,295		3,502,994
Liabilities:
Securitized debt obligations, net	2,841,901		2,838,062
Other liabilities	3,316		1,800
Liabilities	$ 2,845,217		$ 2,839,862