Earnings Per Common Share ("EPS") (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net Income		$ 1,575	$ 904	$ 1,294
Weighted-average common shares outstanding (for basic calculation) (in shares)		297.0	302.0	306.0
Effect of dilutive share-based employee compensation (in shares)		5.0	5.0	7.0
Weighted-average common and dilutive potential common shares outstanding (for diluted calculation) (in shares)		302.0	307.0	313.0
Basic EPS (in dollars per share)		$ 5.30	$ 2.99	$ 4.23
Diluted EPS (in dollars per share)		$ 5.21	$ 2.94	$ 4.14
Unexercised employee stock options and stock appreciation rights (in millions) excluded from the diluted EPS computation (in shares)	[1]	1.1	4.8	2.0

[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.