Derivative Instruments - Asset and Liability Management Derivative Positions (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Derivative [Line Items]
Notional Value	$ 1,400,000
Other economic hedges | Equity contracts
Derivative [Line Items]
Notional Value	8	$ 0
Fair Value, Assets	0	0
Fair Value, Liabilities	0	0
Asset and Liability Management Positions
Derivative [Line Items]
Notional Value	103,569	105,692
Fair Value, Assets	319	275
Fair Value, Liabilities	258	221
Asset and Liability Management Positions | Swaps | Visa Class B Shares
Derivative [Line Items]
Fair Value, Liabilities	115	78
Derivative liability notional value	1,000	1,000
Asset and Liability Management Positions | Underwriting Purchase and Sale Commitments
Derivative [Line Items]
Notional Value	1,800
Asset and Liability Management Positions | Other
Derivative [Line Items]
Notional Value	2,846	1,084
Fair Value, Assets	8	7
Fair Value, Liabilities	118	78
Asset and Liability Management Positions | Other economic hedges | Interest rate contracts | Receive fixed/pay floating swaps
Derivative [Line Items]
Notional Value	9,396	9,977
Fair Value, Assets	109	45
Fair Value, Liabilities	30	23
Asset and Liability Management Positions | Other economic hedges | Interest rate contracts | Pay fixed/receive floating swaps
Derivative [Line Items]
Notional Value	2,983	2,371
Fair Value, Assets	0	0
Fair Value, Liabilities	0	0
Asset and Liability Management Positions | Other economic hedges | Interest rate contracts | Futures and forwards | Buy/ Purchased
Derivative [Line Items]
Notional Value	8,544	5,436
Fair Value, Assets	14	8
Fair Value, Liabilities	12	30
Asset and Liability Management Positions | Other economic hedges | Interest rate contracts | Futures and forwards | Sell/ Written
Derivative [Line Items]
Notional Value	3,283	2,711
Fair Value, Assets	4	10
Fair Value, Liabilities	12	1
Asset and Liability Management Positions | Other economic hedges | Interest rate contracts | Options | Buy/ Purchased
Derivative [Line Items]
Notional Value	9,520	7,810
Fair Value, Assets	145	186
Fair Value, Liabilities	0	0
Asset and Liability Management Positions | Other economic hedges | Interest rate contracts | Options | Sell/ Written
Derivative [Line Items]
Notional Value	3,181	1,991
Fair Value, Assets	21	8
Fair Value, Liabilities	66	47
Asset and Liability Management Positions | Other economic hedges | Foreign exchange forward contracts
Derivative [Line Items]
Notional Value	774	702
Fair Value, Assets	4	4
Fair Value, Liabilities	1	4
Asset and Liability Management Positions | Other economic hedges | Equity contracts
Derivative [Line Items]
Notional Value	321	293
Fair Value, Assets	8	0
Fair Value, Liabilities	1	9
Asset and Liability Management Positions | Other economic hedges | Credit contracts
Derivative [Line Items]
Notional Value	2,816	3,558
Fair Value, Assets	0	0
Fair Value, Liabilities	18	29
Asset and Liability Management Positions | Fair value hedges | Interest rate contracts | Receive fixed/pay floating swaps
Derivative [Line Items]
Notional Value	8,550	10,600
Fair Value, Assets	0	0
Fair Value, Liabilities	0	0
Asset and Liability Management Positions | Fair value hedges | Interest rate contracts | Pay fixed/receive floating swaps
Derivative [Line Items]
Notional Value	26,614	29,739
Fair Value, Assets	0	0
Fair Value, Liabilities	0	0
Asset and Liability Management Positions | Cash flow hedges | Interest rate contracts | Receive fixed/pay floating swaps
Derivative [Line Items]
Notional Value	23,000	28,550
Fair Value, Assets	0	0
Fair Value, Liabilities	0	0
Asset and Liability Management Positions | Cash flow hedges | Interest rate contracts | Pay fixed/receive floating swaps
Derivative [Line Items]
Notional Value	1,000	0
Fair Value, Assets	0	0
Fair Value, Liabilities	0	0
Asset and Liability Management Positions | Net investment hedges | Foreign exchange forward contracts
Derivative [Line Items]
Notional Value	741	870
Fair Value, Assets	6	7
Fair Value, Liabilities	$ 0	$ 0