Fair Value Measurement - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Assets:
Fair Value	$ 79,117	$ 76,919
Loans held for sale	$ 347	$ 191
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Other assets:
Derivative assets, gross amount	$ 2,675	$ 3,098
Derivative Asset, netting adjustments	(1,005)	(1,134)
Derivative asset	1,670	1,964
Liabilities:
Derivative liabilities, gross amount	2,932	4,550
Derivative Liability, netting adjustments	(597)	(1,235)
Derivative liability	$ 2,335	$ 3,315
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Net valuation allowance	$ 2	$ 4
Level 1
Assets:
Loans held for sale	0	0
Level 2
Assets:
Loans held for sale	515	11
Level 3
Assets:
Loans held for sale	0	0
Recurring
Assets:
Fair Value	79,117	76,919
Loans held for sale	347	191
Other assets:
Derivative asset	1,670	1,964
Other	627	503
Total	81,761	79,577
Liabilities:
Derivative liability	2,335	3,315
Recurring | Level 1
Assets:
Fair Value	5,408	5,227
Loans held for sale	0	0
Other assets:
Derivative assets, gross amount	788	474
Other	589	464
Total	6,785	6,165
Liabilities:
Derivative liabilities, gross amount	449	823
Deferred compensation plan assets	578	453
Recurring | Level 2
Assets:
Fair Value	73,431	71,314
Loans held for sale	347	191
Other assets:
Derivative assets, gross amount	1,001	2,545
Other	3	3
Total	74,782	74,053
Liabilities:
Derivative liabilities, gross amount	1,655	3,653
Recurring | Level 3
Assets:
Fair Value	278	378
Loans held for sale	0	0
Other assets:
Derivative assets, gross amount	886	79	$ 84
Other	35	36
Total	1,199	493
Liabilities:
Derivative liabilities, gross amount	828	74	$ 65
Retained interests in securitizations	35	36
Recurring | Fair Value Inputs Level 1 And Level 2
Liabilities:
Equity securities	14	14
Debt and equity securities, unrealized gain (loss)	5	(23)
U.S. Treasury securities
Assets:
Fair Value	5,282	5,041
U.S. Treasury securities | Recurring
Assets:
Fair Value	5,282	5,041
U.S. Treasury securities | Recurring | Level 1
Assets:
Fair Value	5,282	5,041
U.S. Treasury securities | Recurring | Level 2
Assets:
Fair Value	0	0
U.S. Treasury securities | Recurring | Level 3
Assets:
Fair Value	0	0
Total RMBS
Assets:
Fair Value	63,638	62,589
Total RMBS | Recurring
Assets:
Fair Value	63,638	62,589
Total RMBS | Recurring | Level 1
Assets:
Fair Value	0	0
Total RMBS | Recurring | Level 2
Assets:
Fair Value	63,492	62,353
Total RMBS | Recurring | Level 3
Assets:
Fair Value	146	236
CMBS | Recurring
Assets:
Fair Value	8,323	7,870
CMBS | Recurring | Level 1
Assets:
Fair Value	0	0
CMBS | Recurring | Level 2
Assets:
Fair Value	8,191	7,728
CMBS | Recurring | Level 3
Assets:
Fair Value	132	142
Other securities
Assets:
Fair Value	1,874	1,419
Other securities | Recurring
Assets:
Fair Value	1,874	1,419
Other securities | Recurring | Level 1
Assets:
Fair Value	126	186
Other securities | Recurring | Level 2
Assets:
Fair Value	1,748	1,233
Other securities | Recurring | Level 3
Assets:
Fair Value	$ 0	$ 0