Regulatory Capital and Other Regulatory Matters (Common Share Repurchases) (Details) - USD ($)		3 Months Ended						6 Months Ended
	Jul. 14, 2022	Jun. 30, 2022		Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021		Jun. 30, 2022		Jun. 30, 2021		Jan. 10, 2022	Sep. 30, 2021	Jul. 12, 2021	Mar. 31, 2021	Jan. 11, 2021	Dec. 31, 2020
Accelerated Share Repurchases [Line Items]
Cash dividends declared per common share (in dollars per share)		$ 0.30	[1]		$ 0.25	$ 0.19	[1]	$ 0.60	[1]	$ 0.38	[1]
Treasury stock, common, amount		$ 600,000,000		$ 584,000,000	$ 594,000,000	$ 502,000,000		$ 600,000,000		$ 502,000,000			$ 679,000,000		$ 219,000,000
Treasury stock, common, shares (in shares)		15,031,000		12,548,000	12,046,000	9,641,000		15,031,000		9,641,000			13,055,000		5,276,000
Common stock, shares outstanding (in shares)		312,781,366		327,306,000	337,940,636	362,639,000		312,781,366		362,639,000			349,599,000		371,805,000		374,674,000
Dividends declared (in dollars per share)		$ 0.30		$ 0.30	$ 0.25	$ 0.19		$ 0.30		$ 0.19			$ 0.25		$ 0.19
Common stock
Accelerated Share Repurchases [Line Items]
Stock repurchase program, authorized amount												$ 2,000,000,000		$ 2,000,000,000		$ 1,600,000,000
Cash dividends declared per common share (in dollars per share)				$ 0.30
Common stock | Subsequent event
Accelerated Share Repurchases [Line Items]
Cash dividends declared per common share (in dollars per share)	$ 0.30
Dividends payable, date declared	Jul. 14, 2022
Dividends payable, date to be paid	Aug. 15, 2022
Dividends payable, date of record	Aug. 01, 2022
Series B Preferred Stock
Accelerated Share Repurchases [Line Items]
Gross proceeds from issuance of series preferred stock						$ 1,350,000,000
Series C Preferred Stock
Accelerated Share Repurchases [Line Items]
Gross proceeds from issuance of series preferred stock						$ 1,000,000,000

[1] Figures in the table may not recalculate exactly due to rounding. Earnings per share is calculated based on unrounded numbers.