Fair Value, Assets and Liabilities, Fair Value on a Nonrecurring Basis (Details) - Nonrecurring [Member] - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	$ 2,353	$ 5,318
Loans	697	856
Other assets	1,803	1,548
Total assets at fair value on a nonrecurring basis	10,160	15,316
Nonmarketable equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonmarketable equity securities	5,232	7,027
Total Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	206	476
Mortgage servicing rights	75	567
Total Consumer [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	491	380
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	840	3,911
Loans	697	856
Other assets	1,560	1,373
Total assets at fair value on a nonrecurring basis	4,663	12,402
Level 2 [Member] | Nonmarketable equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonmarketable equity securities	1,566	6,262
Level 2 [Member] | Total Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	206	476
Mortgage servicing rights	0	0
Level 2 [Member] | Total Consumer [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	491	380
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	1,513	1,407
Loans	0	0
Other assets	243	175
Total assets at fair value on a nonrecurring basis	5,497	2,914
Level 3 [Member] | Nonmarketable equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonmarketable equity securities	3,666	765
Level 3 [Member] | Total Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0
Mortgage servicing rights	75	567
Level 3 [Member] | Total Consumer [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	$ 0	$ 0