Capital Stock and Share Based Compensation Plans - Cash proceeds (Details) (Stock Options, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash received upon exercise	$ 46,624		$ 18,215		$ 2,514
Intrinsic value (market value on date of exercise less exercise price)	18,468		2,378		446
Tax benefits realized (1)	$ 6,926	[1]	$ 892	[1]	$ 167	[1]

[1] Benefits to be recognized in future years when realizable.