Investment Securities (Summary Of Net Gain From Sale Of Agency Securities) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cost of Sale of Fair Value Option Securities	$ (29,427)	$ (30,903)	$ (74,964)
Cost of Sale of Investment Securities	(30,213)	(35,875)	(77,274)
Proceeds from Sale of Debt Securities	27,297	35,818	78,400
Proceeds from Sale of Debt Securities, Trading	26,553	30,810	76,009
Proceeds from Sale of Debt Securities, Available-for-sale	(744)	(5,008)	(2,391)
Net gain (loss) on sale of investment securities	(2,916)	(57)	1,126
Available-for-sale Securities [Member]
Agency MBS sold, at cost	786	4,972	2,310
Net gain (loss) on sale of investment securities		36	81
Debt Securities, Available-for-sale, Realized Gain	2	36	81
Debt Securities, Available-for-sale, Realized Loss	44	0	0
Securities Remeasured at Fair Value [Member]
Net gain (loss) on sale of investment securities		(93)	1,045
Debt Securities, Available-for-sale, Realized Gain	10	176	1,149
Debt Securities, Available-for-sale, Realized Loss	2,884	269	104
Securities (Assets) [Member]
Net gain (loss) on sale of investment securities	(2,916)	(57)	1,126
Debt Securities, Available-for-sale, Realized Gain	12	212	1,230
Debt Securities, Available-for-sale, Realized Loss	2,928	$ 269	$ 104
Cost and Proceeds of Investment Securities [Member] \| Available-for-sale Securities [Member]
Net gain (loss) on sale of investment securities	(42)
Cost and Proceeds of Investment Securities [Member] \| Securities Remeasured at Fair Value [Member]
Net gain (loss) on sale of investment securities	(2,874)
Gross Gain & Loss of Investment Securities [Member] \| Available-for-sale Securities [Member]
Net gain (loss) on sale of investment securities	(42)
Gross Gain & Loss of Investment Securities [Member] \| Securities Remeasured at Fair Value [Member]
Net gain (loss) on sale of investment securities	$ (2,874)

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