Earnings Per Common Share ("EPS") (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Net Income		$ 418	$ 224	$ 718	$ 623
Weighted-average common shares outstanding (for basic calculation)		281.0	286.0	281.0	288.0
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	290.0	286.0	292.0
Basic EPS		$ 1.49	$ 0.78	$ 2.55	$ 2.16
Diluted EPS		$ 1.46	$ 0.77	$ 2.51	$ 2.13
Unexercised employee stock options and stock appreciation rights (in millions) excluded from the diluted EPS computation	[1]	1.7	2.4	1.6	1.8

[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.