Shareholders' Equity - Data for stock options issued under the stock incentive plans (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at January 1, 2016	5,516,090
Exercised	(958,344)
Forfeited/Cancelled	(52,645)
Outstanding at December 31, 2016	4,505,101	5,516,090
Options exercisable at December 31, 2016	2,908,200
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Average exercise price, Beginning balance	$ 41.46
Average exercise price, Granted		$ 63.15	$ 56.47
Average exercise price, Exercised	33.56
Average exercise price, Forfeited/Cancelled	51.91
Average exercise price, Ending balance	43.02	$ 41.46
Average exercise price, Options exercisable	$ 36.95
Average remaining contractual term, Options outstanding	5 years 4 months 24 days
Average remaining contractual term, Options exercisable	4 years 4 months 24 days
Aggregate intrinsic value, Options outstanding	$ 203
Aggregate intrinsic value, Options exercisable	$ 149