Stock-Based Compensation (Schedule of Stock-Based Compensation Activity) (Details) - Stock Option $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding
Outstanding at January 1, 2019 | shares	7,186
Granted | shares	1,197
Exercised | shares	(2,239)
Forfeited or expired | shares	(252)
Outstanding at December 31, 2019 | shares	5,892
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price
Outstanding at January 1, Weighted-Average Exercise Price | $ / shares	$ 110.27
Granted, Weighted-Average Exercise Price | $ / shares	125.52
Exercised, Weighted-Average Exercise Price | $ / shares	102.88
Forfeited or expired, Weighted-Average Exercise Price | $ / shares	119.14
Outstanding at December 31, Weighted-Average Exercise Price | $ / shares	$ 115.26
Exercisable at December 31, 2019 | shares	3,444
Exercisable at December 31, Weighted-Average Exercise Price | $ / shares	$ 113.49
Outstanding at December 31, Weighted-Average Remaining Contractual Term	6 years 5 months 15 days
Exercisable at December 31, Weighted-Average Remaining Contractual Term	4 years 11 months 26 days
Outstanding at December 31, Aggregate Intrinsic Value | $	$ 128
Exercisable at December 31, Aggregate Intrinsic Value | $	$ 81