Earnings Per Common Share ("EPS") (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Net Income		$ 416	$ 331	$ 1,134	$ 954
Weighted-average common shares outstanding (for basic calculation)		281.0	285.0	281.0	287.0
Effect of dilutive share-based employee compensation		5.0	4.0	5.0	4.0
Weighted-average common and dilutive potential common shares outstanding (for diluted calculation)		286.0	289.0	286.0	291.0
Basic EPS		$ 1.48	$ 1.16	$ 4.03	$ 3.33
Diluted EPS		$ 1.46	$ 1.14	$ 3.97	$ 3.28
Unexercised employee stock options and stock appreciation rights (in millions) excluded from the diluted EPS computation	[1]	1.7	2.0	1.7	1.9

[1] These unexercised employee stock options and stock appreciation rights were not included in the computation of diluted EPS because to do so would have been antidilutive for the periods presented.