Investments in Limited Partnerships - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) Partnership	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Schedule of Investments [Line Items]
Unfunded equity commitments in other liabilities	$ 15,179,312	$ 14,505,243
Tax benefits including low-income housing and historic tax credits	35,017	44,288	$ 59,589
Partnerships losses and impairment	$ 4,200	3,600	3,400
Number of limited partnerships held | Partnership	4
Gains (losses) related to equity method investments	$ 159,032	192,113	242,260
Equity Method Investments [Member]
Schedule of Investments [Line Items]
Tax benefits including low-income housing and historic tax credits	3,800	3,500	3,100
Limited Liability Company [Member]
Schedule of Investments [Line Items]
Amount invested in partnerships	3,000	3,300
Limited Liability Company [Member] | Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Schedule of Investments [Line Items]
Partnership income (loss) under equity method	35	(900)	3,600
Gains (losses) related to equity method investments	100	(1,000)	$ 3,800
Variable Interest Entity, Not Primary Beneficiary [Member]
Schedule of Investments [Line Items]
Unfunded equity commitments in other liabilities	13,900	15,100
Variable Interest Entity, Not Primary Beneficiary [Member] | Other Assets [Member]
Schedule of Investments [Line Items]
Amount invested in partnerships	$ 31,900	$ 34,200