Variable Interest Entities - Summary of Quantitative Information Related to Significant Involvement in Unconsolidated Variable Interest Entities (Detail) - USD ($) $ in Thousands		Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Variable Interest Entity [Line Items]
Aggregate Assets		$ 28,777,896	$ 29,328,902
Aggregate Liabilities		24,290,846	24,610,274
Risk Of Loss		28,777,896		$ 27,190,926
Trust Preferred Securities [Member]
Variable Interest Entity [Line Items]
Aggregate Assets		299,748	299,531
Aggregate Liabilities		288,634	288,499
Risk Of Loss	[1]	$ 11,114	$ 11,032

[1] Represents investment in VIEs.