Noninterest Income - Wealth Management and Trust Fees (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 1,314	$ 1,057	$ 880
Wealth management fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	40	0	0
Trust fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4	0	0
Wealth management and trust fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 44	$ 0	$ 0