Equity - Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Dividends Payable [Line Items]
Preferred Stock, Shares Authorized	200,000,000	200,000,000
Preferred Stock, Shares Issued	25,572,200	25,572,200
Preferred Stock, Shares Outstanding	25,572,200	25,572,200
Preferred Stock
Preferred stock, dividends	$ 200	$ 198	$ 185
Series A Preferred Stock [Member]
Dividends Payable [Line Items]
Preferred Stock, Dividend Payment Rate, Variable	Three-month CME Term SOFR plus a spread adjustment of 0.26161% + 1.000%, with floor of 4.000%
Preferred Stock, Shares Authorized	27,600,000	27,600,000
Preferred Stock, Shares Issued	24,000,000	24,000,000
Preferred Stock, Shares Outstanding	24,000,000	24,000,000
Preferred Stock
Preferred Stock, Dividends Per Share, Declared	$ 1.659	$ 1.577	$ 1.033
Preferred stock, dividends	$ 39	$ 37	$ 24
5.875% Fixed-to-Floating Rate Non-Cumulative Preferred Stock, Series D, par value $0.01
Dividends Payable [Line Items]
Preferred Stock, Dividend Payment Rate, Variable	5.875% Fixed-to-Floating Rate
Preferred Stock, Shares Authorized	500,000	500,000
Preferred Stock, Shares Issued	500,000	500,000
Preferred Stock, Shares Outstanding	500,000	500,000
Preferred Stock
Preferred Stock, Dividends Per Share, Declared	$ 58.750	$ 58.750	$ 58.750
Preferred stock, dividends	$ 29	$ 29	$ 29
Series E Preferred Stock [Member]
Dividends Payable [Line Items]
Preferred Stock, Shares Authorized	32,200	32,200
Preferred Stock, Shares Issued	32,200	32,200
Preferred Stock, Shares Outstanding	32,200	32,200
Preferred Stock
Preferred Stock, Dividends Per Share, Declared	$ 1,406.252	$ 1,406.252	$ 1,406.252
Preferred stock, dividends	$ 45	$ 45	$ 45
Series A Junior Preferred Stock [Member]
Dividends Payable [Line Items]
Preferred Stock, Shares Authorized	10,000,000	10,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Not Designated Preferred Stock [Member]
Dividends Payable [Line Items]
Preferred Stock, Shares Authorized	160,827,800	160,827,800
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Depositary Shares, each representing a 1/1,000th interest in a share of 4.75% Non-Cumulative Preferred Stock, Series F
Dividends Payable [Line Items]
Preferred Stock, Shares Authorized	40,000	40,000
Preferred Stock, Shares Issued	40,000	40,000
Preferred Stock, Shares Outstanding	40,000	40,000
Preferred Stock
Preferred Stock, Dividends Per Share, Declared	$ 1,187.5	$ 1,187.5	$ 1,187.5
Preferred stock, dividends	$ 48	$ 48	$ 48
3.850% Fixed Rate Reset Non-Cumulative Preferred Stock, Series G, par value $0.01
Dividends Payable [Line Items]
Preferred Stock, Shares Authorized	1,000,000	1,000,000
Preferred Stock, Shares Issued	1,000,000	1,000,000
Preferred Stock, Shares Outstanding	1,000,000	1,000,000
Preferred Stock
Preferred Stock, Dividends Per Share, Declared	$ 38.500	$ 38.500	$ 38.500
Preferred stock, dividends	$ 39	$ 39	$ 39