Asset Quality - Additional Information (Details) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022 USD ($) loan	Jun. 30, 2021 USD ($) loan	Jun. 30, 2022 USD ($) loan	Jun. 30, 2021 USD ($) loan	Dec. 31, 2021 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of carrying amount of our commercial nonperforming loans outstanding (as a percent)	61.00%		61.00%
Percentage of nonperforming loans outstanding face value (as a percent)	72.00%		72.00%
Percentage of loans held for sale and other nonperforming assets (as a percent)	80.00%		80.00%
Net reduction to interest income	$ 4	$ 7	$ 9	$ 14
Commitments outstanding to lend additional funds to borrowers (less than $1 million)	1		1		$ 15
Financial receivable, modifications, subsequent default, recorded investment	2	$ 1	10	$ 2
Real estate — residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment			155		$ 104
Non-performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonperforming loans on nonaccrual status with no allowance	$ 239		$ 239
Total commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDRs, period for default (in days)			90 days
Number of loans | loan	1	1	5	3
Total commercial loans | Continuing Operations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Decrease in ALLL	$ (8)
Decrease in ALLL (as a percent)	(1.10%)
Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDRs, period for default (in days)			60 days
Number of loans | loan	52	29	90	65
Total consumer loans | Continuing Operations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Decrease in ALLL	$ 2
Decrease in ALLL (as a percent)	0.50%