Noninterest Income - Lending Related Fees (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Lending related fees	$ 18	$ 11	$ 34	$ 24
Unused commitment fees
Accounts, Notes, Loans and Financing Receivable [Line Items]
Lending related fees	15	8	28	17
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Lending related fees	$ 3	$ 3	$ 6	$ 7