Earnings Per Common Share (EPS) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2024		Sep. 30, 2023		Sep. 30, 2024		Sep. 30, 2023
Basic and diluted:
Net income	$ 2,507		$ 2,451		$ 7,959		$ 6,441
Preferred dividends	(15)		(14)		(44)		(43)
Net income available to common shareholders	2,492		2,437		7,915		6,398
Earnings allocated to participating share awards	(18)		(19)		(59)		(50)
Net income attributable to common shareholders	$ 2,474		$ 2,418		$ 7,856		$ 6,348
Denominator:
Basic: Weighted-average common stock (in shares)	708.0		732.0		715.0		738.0
Add: Weighted-average stock options (in shares)	1.0		1.0		1.0		1.0
Diluted (in shares)	709.0		733.0		716.0		739.0
Basic EPS (in dollars per share)	$ 3.50	[1]	$ 3.30	[1]	$ 10.99	[2]	$ 8.60	[2]
Diluted EPS (in dollars per share)	$ 3.49	[1]	$ 3.30	[1]	$ 10.97	[2]	$ 8.59	[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 $18 million and $19 million for the three months ended September 30, 2024 and 2023, respectively, and (ii) dividends on preferred shares of $15 million and $14 million for the three months ended September 30, 2024 and 2023, respectively.

[2] Represents net income less (i) earnings allocated to participating share awards of $59 million and $50 million for the nine months ended September 30, 2024 and 2023, respectively, and (ii) dividends on preferred shares of $44 million and $43 million for the nine months ended September 30, 2024 and 2023, respectively.