Asset Quality - Changes in Liability for Credit Losses on Lending Related Commitments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at the end of the prior period	$ 197	$ 68
Liability for credit losses on contingent guarantees at the end of the prior period		0	$ 7
Provision (credit) for losses on off balance sheet exposures	(37)	56	4
Balance at end of period	160	197	68
Provision (credit) for losses on lending-related commitments			4
Impact of ASC 326 Adoption
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Cumulative effect from change in accounting principle		0	66
Adjusted balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at the end of the prior period	$ 197	141
Balance at end of period		$ 197	$ 141