Shareholders' Equity (Details 1) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, Beginning balance	7,922,474
Granted	1,076,500
Exercised	(1,702,782)
Forfeited/Cancelled	(76,450)
Options outstanding, Ending balance	7,219,742
Options exercisable	4,405,197
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Average exercise price, Beginning balance	$ 27.05
Average exercise price, Granted	$ 38.10
Average exercise price, Exercised	$ 23.86
Average exercise price, Forfeited/Cancelled	$ 31.22
Average exercise price, Ending balance	$ 29.40
Average exercise price, Options exercisable	$ 28.13
Average remaining contractual term, Options outstanding	5 years 6 months
Average remaining contractual term, Options exercisable	4 years
Aggregate intrinsic value, Options outstanding	$ 73
Aggregate intrinsic value, Options exercisable	$ 50