Derivative Instruments - Summary of Asset and Liability Management Derivative Positions of Company (Detail) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Derivative [Line Items]
Notional Value	$ 1,800,000
Asset and Liability Management Positions [Member]
Derivative [Line Items]
Notional Value	103,877	$ 90,763
Fair Value, Assets	312	396
Fair Value, Liabilities	298	422
Asset and Liability Management Positions [Member] | Other Derivatives [Member]
Derivative [Line Items]
Notional Value	2,273	1,908
Fair Value, Assets	11	11
Fair Value, Liabilities	146	190
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Receive Fixed/Pay Floating Swaps [Member]
Derivative [Line Items]
Notional Value	5,105	9,215
Fair Value, Liabilities		3
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Pay Fixed/Receive Floating Swaps [Member]
Derivative [Line Items]
Notional Value	5,117	9,616
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Futures and Forwards [Member] | Purchased [Member]
Derivative [Line Items]
Notional Value	4,943	3,546
Fair Value, Assets	4	10
Fair Value, Liabilities	8	18
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Futures and Forwards [Member] | Written [Member]
Derivative [Line Items]
Notional Value	5,966	7,522
Fair Value, Assets	25	20
Fair Value, Liabilities	5	38
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Options [Member] | Purchased [Member]
Derivative [Line Items]
Notional Value	8,815	11,434
Fair Value, Assets	249	346
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Options [Member] | Written [Member]
Derivative [Line Items]
Notional Value	6,451	7,849
Fair Value, Assets	19	7
Fair Value, Liabilities	129	148
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Foreign Exchange Forward Contracts [Member]
Derivative [Line Items]
Notional Value	687	962
Fair Value, Assets	1	2
Fair Value, Liabilities	2	6
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Equity Contracts [Member]
Derivative [Line Items]
Notional Value	207	361
Fair Value, Assets	2
Fair Value, Liabilities	1	10
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Credit Contracts [Member]
Derivative [Line Items]
Notional Value	625	330
Fair Value, Assets	1
Asset and Liability Management Positions [Member] | Fair Value Hedges [Member] | Interest Rate Contracts [Member] | Receive Fixed/Pay Floating Swaps [Member]
Derivative [Line Items]
Notional Value	19,650	17,400
Fair Value, Liabilities	3	9
Asset and Liability Management Positions [Member] | Fair Value Hedges [Member] | Interest Rate Contracts [Member] | Pay Fixed/Receive Floating Swaps [Member]
Derivative [Line Items]
Notional Value	16,514	5,542
Asset and Liability Management Positions [Member] | Cash Flow Hedges [Member] | Interest Rate Contracts [Member] | Receive Fixed/Pay Floating Swaps [Member]
Derivative [Line Items]
Notional Value	26,700	14,300
Asset and Liability Management Positions [Member] | Net Investment Hedges [Member] | Foreign Exchange Forward Contracts [Member]
Derivative [Line Items]
Notional Value	824	$ 778
Fair Value, Liabilities	$ 4