Derivative Instruments and Hedging Activities (Fair Value Amounts of Derivative Instruments Reported on our Condensed Consolidated Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
receivable position	$ 22	$ 23
payable position	14	42
Notional amount	39,851	33,833
Credit derivative, maximum exposure, undiscounted	38	82
Total derivatives designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	20	22
payable position	0	1
Notional amount	39,607	33,570
Total derivatives not designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	2	1
payable position	14	41
Notional amount	244	263
Interest rate contracts | Total derivatives not designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	2	0
payable position	0	0
Notional amount	187	116
Swaps | Total derivatives designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	0	0
payable position	0	0
Notional amount	33,194	30,619
Purchased options | Total derivatives designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	19	22
payable position	0	0
Notional amount	6,250	2,800
Futures and forwards | Total derivatives not designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	1	0
payable position	0	0
Notional amount	84	37
Written options | Total derivatives not designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	1	0
payable position	0	0
Notional amount	103	79
Foreign exchange contracts | Total derivatives not designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	0	0
payable position	0	1
Notional amount	57	147
Forwards | Total derivatives designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	1	0
payable position	0	1
Notional amount	163	151
Futures and forwards | Total derivatives not designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	0	0
payable position	0	1
Notional amount	57	147
Other credit derivatives | Total derivatives not designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	0	0
payable position	14	39
Equity contracts | Total derivatives not designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	0	1
payable position	0	1
Notional amount	0	0
Written options | Total derivatives not designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	0	0
payable position	0	1
Notional amount	0	0
Purchased options | Total derivatives not designated as accounting hedges
Derivatives, Fair Value [Line Items]
receivable position	0	1
payable position	0	0
Notional amount	$ 0	$ 0