Shareholders' Equity - Schedule of Stock Repurchases (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		96 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020
Equity, Class of Treasury Stock [Line Items]
Total repurchase cost	$ 463	$ 101
2012 - Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Shares purchased (in shares)	2.2	0.6	130.9
Average price per share of stock repurchased (in dollars per share)	$ 212.78	$ 161.16
Total repurchase cost	$ 461	$ 100	$ 13,400
Additional associated costs	2	1
Total costs recorded to retained earnings	$ 463	$ 101