Earnings Per Common Share (EPS) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Basic and diluted:
Net income		$ 8,374	$ 7,514	$ 8,060
Preferred dividends		(58)	(57)	(71)
Equity-related adjustments		0	0	(16)
Net income available to common shareholders		8,316	7,457	7,973
Earnings allocated to participating share awards		(64)	(57)	(56)
Net income attributable to common shareholders		$ 8,252	$ 7,400	$ 7,917
Denominator:
Basic: Weighted-average common stock (in shares)		735,000	751,000	789,000
Add: Weighted-average stock options (in shares)		1,000	1,000	1,000
Diluted (in shares)		736,000	752,000	790,000
Basic EPS (in dollars per share)	[1]	$ 11.23	$ 9.86	$ 10.04
Diluted EPS (in dollars per share)	[1]	$ 11.21	$ 9.85	$ 10.02
Stock Option
Denominator:
Antidilutive securities excluded from computation of earnings per share (in shares)		1,380	390	10

[1] Represents net income less (i) earnings allocated to participating share awards of $64 million, $57 million and $56 million for the years ended December 31, 2023, 2022 and 2021, respectively, (ii) dividends on preferred shares of $58 million, $57 million and $71 million for the years ended December 31, 2023, 2022 and 2021, respectively, and (iii) equity-related adjustments of $16 million related to the redemption of preferred shares for the year ended December 31, 2021.