Derivative Instruments - Summary of Asset and Liability Management Derivative Positions of Company (Detail) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Notional Value	$ 1,200,000
Asset and Liability Management Positions [Member]
Derivative [Line Items]
Notional Value	111,657	$ 90,763
Fair Value, Assets	427	396
Fair Value, Liabilities	387	422
Asset and Liability Management Positions [Member] | Other Derivatives [Member]
Derivative [Line Items]
Notional Value	2,140	1,908
Fair Value, Assets	12	11
Fair Value, Liabilities	158	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	8,504	9,215
Fair Value, Assets	1
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	9,190	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	8,120	3,546
Fair Value, Assets	29	10
Fair Value, Liabilities	15	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	6,891	7,522
Fair Value, Assets	12	20
Fair Value, Liabilities	32	38
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Options [Member] | Purchased [Member]
Derivative [Line Items]
Notional Value	14,109	11,434
Fair Value, Assets	344	346
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Interest Rate Contracts [Member] | Options [Member] | Written [Member]
Derivative [Line Items]
Notional Value	10,295	7,849
Fair Value, Assets	20	7
Fair Value, Liabilities	159	148
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Foreign Exchange Forward Contracts [Member]
Derivative [Line Items]
Notional Value	1,124	962
Fair Value, Assets	2	2
Fair Value, Liabilities	7	6
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Equity Contracts [Member]
Derivative [Line Items]
Notional Value	361	361
Fair Value, Assets	6
Fair Value, Liabilities	7	10
Asset and Liability Management Positions [Member] | Other Economic Hedges [Member] | Credit Contracts [Member]
Derivative [Line Items]
Notional Value	375	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	17,400	17,400
Fair Value, Liabilities		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	13,564	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	18,800	14,300
Asset and Liability Management Positions [Member] | Net Investment Hedges [Member] | Foreign Exchange Forward Contracts [Member]
Derivative [Line Items]
Notional Value	784	$ 778
Fair Value, Liabilities	$ 9