Regulatory Capital and Other Regulatory Matters (Common Share Repurchases) (Details)			3 Months Ended	12 Months Ended
		Jan. 17, 2023 $ / shares	Jun. 30, 2021 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 $ / shares shares	Sep. 30, 2022 USD ($) $ / shares shares	Jun. 30, 2022 USD ($) $ / shares shares	Mar. 31, 2022 USD ($) $ / shares shares	Jan. 10, 2022 USD ($)	Sep. 30, 2021 USD ($) $ / shares shares	Jul. 12, 2021 USD ($)	Mar. 31, 2021 USD ($) $ / shares shares	Jan. 11, 2021 USD ($)	Jun. 30, 2016 shares
Accelerated Share Repurchases [Line Items]
Minimum capital conservation buffer				0.025
Dividends declared (in dollars per share) | $ / shares			$ 0.19	$ 0.30	$ 0.25		$ 0.30	$ 0.30	$ 0.30		$ 0.25		$ 0.19
Treasury stock, common, amount			$ 502,000,000	$ 51,000,000	$ 594,000,000		$ 415,000,000	$ 600,000,000	$ 584,000,000		$ 679,000,000		$ 219,000,000
Treasury stock, common, shares (in shares) | shares			9,641,000	1,731,000	12,046,000		12,468,000	15,031,000	12,548,000		13,055,000		5,276,000
Common stock, share reduction				38.00%
Common stock, shares outstanding (in shares) | shares			362,639,000	299,324,357	337,940,636	374,674,000	300,335,000	312,781,000	327,306,000		349,599,000		371,805,000		484,000,000
Cash dividends declared per common share (in dollars per share) | $ / shares	[1]			$ 1.20	$ 0.88	$ 0.76
Subsequent event
Accelerated Share Repurchases [Line Items]
Cash dividends declared per common share (in dollars per share) | $ / shares		$ 0.30
Common stock
Accelerated Share Repurchases [Line Items]
Stock repurchase program, authorized amount										$ 2,000,000,000		$ 2,000,000,000		$ 1,600,000,000
Treasury stock, common, amount				$ 1,650,000,000
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.