Earnings Per Common Share (EPS) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2024		Jun. 30, 2023		Jun. 30, 2024		Jun. 30, 2023
Basic and diluted:
Net income	$ 3,015		$ 2,174		$ 5,452		$ 3,990
Preferred dividends	(15)		(15)		(29)		(29)
Net income available to common shareholders	3,000		2,159		5,423		3,961
Earnings allocated to participating share awards	(23)		(17)		(41)		(31)
Net income attributable to common shareholders	$ 2,977		$ 2,142		$ 5,382		$ 3,930
Denominator:
Basic: Weighted-average common stock (in shares)	716.0		740.0		718.0		741.0
Add: Weighted-average stock options (in shares)	1.0		1.0		1.0		1.0
Diluted (in shares)	717.0		741.0		719.0		742.0
Basic EPS (in dollars per share)	$ 4.16	[1]	$ 2.89	[1]	$ 7.49	[2]	$ 5.30	[2]
Diluted EPS (in dollars per share)	$ 4.15	[1]	$ 2.89	[1]	$ 7.48	[2]	$ 5.29	[2]
Stock Option
Denominator:
The dilutive effect of securities excluded from the calculation of earnings per share (in shares)	0.1		1.4		0.1		1.4

[1] Represents net income less (i) earnings allocated to participating share awards of $23 million and $17 million for the three months ended June 30, 2024 and 2023, respectively, and (ii) dividends on preferred shares of $15 million for both the three months ended June 30, 2024 and 2023.

[2] Represents net income less (i) earnings allocated to participating share awards of $41 million and $31 million for the six months ended June 30, 2024 and 2023, respectively, and (ii) dividends on preferred shares of $29 million for both the six months ended June 30, 2024 and 2023.