Capital - Preferred Stock and Treasury Stock (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Mar. 17, 2017	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Oct. 23, 2018
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Issuance and exercise of FDIC Equity appreciation instrument (in shares)		39,032,006	214,990,316
Preferred stock, par value (in usd per share)		$ 0.01	$ 0.01
Stock repurchased authorized amount					$ 300
Treasury stock, acquired, shares (in shares)		30,000,000	871,710,000,000
Treasury stock, shares average price (in dollars per share)		$ 9.61
Treasury stock, acquired, cost		$ 286	$ 8
Treasury stock repurchased		$ 0	$ 7	$ 0
Fixed-to-Floating Rate Series A Noncumulative Perpetual Preferred Stock
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Issuance and exercise of FDIC Equity appreciation instrument (in shares)	20,600,000
Preferred stock, par value (in usd per share)	$ 0.01
Preferred stock, liquidation preference per share (in dollars per share)	1.00
Stock issued during period, per depository share (in dollars per share)	$ 25
Dividend rate percentage	637.50%
Preferred stock, dividend rate, basis spread on variable rate	3.821%