Stockholders' Equity (Schedule of Treasury Stock) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended			167 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2021
Stockholders' Equity Note [Abstract]
Shares repurchased	6,556,378	5,889,073	9,166,267	69,324,429
Average purchase price per share	$ 152.53	$ 110.41	$ 109.10	$ 83.71
Amount spent on repurchased shares (in millions)	$ 1,000	$ 650	$ 1,000	$ 5,803
Aggregate Board of Directors repurchase authorizations during the period	1,000	$ 500	$ 1,500
Share repurchase plan, authorized repurchase amount	$ 6,866			$ 6,866