Fair Values - Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - Nonrecurring - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Assets at fair value
Loans	$ 5,611	$ 5,700
Other assets—Other investments	8	16
Other assets—ROU assets	16	21
Total	5,635	5,737
Liabilities at fair value
Other liabilities and accrued expenses—Lending commitments	243	265
Total	243	265
Assets
Fair Value Adjustment Disclosure
Gains (losses) from fair value remeasurements	(196)	(480)	$ (60)
Loans
Fair Value Adjustment Disclosure
Gains (losses) from fair value remeasurements	(89)	(354)	18
Goodwill
Fair Value Adjustment Disclosure
Gains (losses) from fair value remeasurements	(8)	0	0
Intangibles
Fair Value Adjustment Disclosure
Gains (losses) from fair value remeasurements	(3)	(2)	0
Other investments
Fair Value Adjustment Disclosure
Gains (losses) from fair value remeasurements	(57)	(56)	(56)
Other assets—Premises, equipment and software
Fair Value Adjustment Disclosure
Gains (losses) from fair value remeasurements	(14)	(45)	(22)
Other assets - ROU assets
Fair Value Adjustment Disclosure
Gains (losses) from fair value remeasurements	(25)	(23)	0
Liabilities
Fair Value Adjustment Disclosure
Gains (losses) from fair value remeasurements	37	(5)	87
Other liabilities and accrued expenses—Lending commitments
Fair Value Adjustment Disclosure
Gains (losses) from fair value remeasurements	37	(5)	$ 87
Level 2
Assets at fair value
Loans	4,035	2,566
Other assets—Other investments	0	0
Other assets—ROU assets	16	21
Total	4,051	2,587
Liabilities at fair value
Other liabilities and accrued expenses—Lending commitments	173	193
Total	173	193
Level 3
Assets at fair value
Loans	1,576	3,134
Other assets—Other investments	8	16
Other assets—ROU assets	0	0
Total	1,584	3,150
Liabilities at fair value
Other liabilities and accrued expenses—Lending commitments	70	72
Total	$ 70	$ 72