Repurchase Agreements And Other Debt (Repurchase Arrangements And Weighted Average Interest Rates Classified By Original Maturities) (Details) $ in Millions	Mar. 31, 2025 USD ($) days	Dec. 31, 2024 USD ($) days
Receivable Under Reverse Repurchase Agreements	$ 17,604	$ 17,137
Repurchase Agreements	$ 66,138	$ 60,798
Weighted Average Interest Rate	4.47%	4.76%
Weighted Average Days to Maturity \| days	18	11
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 17,180	$ 16,676
Maturity Overnight [Member]
Repurchase Agreements	25,700	25,400
30 Days or Less [Member]
Repurchase Agreements	$ 52,438	$ 55,580
Weighted Average Interest Rate	4.47%	4.77%
Weighted Average Days to Maturity \| days	10	10
1 to 3 Months
Repurchase Agreements	$ 9,013	$ 3,782
Weighted Average Interest Rate	4.48%	4.68%
Weighted Average Days to Maturity \| days	43	39
3 to 6 Months
Repurchase Agreements	$ 1,271	$ 0
Weighted Average Interest Rate	4.43%	0.00%
Weighted Average Days to Maturity \| days	112	0
9 to 12 Months
Repurchase Agreements	$ 528	$ 0
Weighted Average Interest Rate	4.42%	0.00%
Weighted Average Days to Maturity \| days	298	0
US Treasury Securities [Member] \| Maturity Overnight [Member]
Repurchase Agreements	$ 2,200
US Treasury Securities [Member] \| 2 Days to 1 Month [Member]
Repurchase Agreements	$ 2,888	$ 1,436
Weighted Average Interest Rate	4.46%	4.68%
Weighted Average Days to Maturity \| days	1	2
FICC [Member]
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 4,100	$ 3,900
US Government Agencies Debt Securities [Member]
Repurchase Agreements	$ 63,250	$ 59,362
Weighted Average Interest Rate	4.47%	4.76%
Weighted Average Days to Maturity \| days	19	11