Share Based Award Share based compensation (Details) - Employee Stock Option [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, Outstanding, Number	2,379,407	2,556,936
Options, Outstanding, Weighted Average Exercise Price	$ 56.90	$ 49.46
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	7 years 1 month
Options, Outstanding, Intrinsic Value	$ 132,963
Options, Grants in Period, Gross	267,641
Options, Grants in Period, Weighted Average Exercise Price	$ 92.00
Options, Exercises in Period	(435,146)
Options, Exercises in Period, Weighted Average Exercise Price	$ 34.77
Options, Nonvested Options Forfeited, Number of Shares	(10,024)
Options, Nonvested Options Forfeited, Weighted Average Grant Date Fair Value	$ 58.20
Options, Vested, Number of Shares	1,287,271
Exercise Price Range, Exercisable Options, Weighted Average Exercise Price	$ 48.45
Options, Exercisable, Weighted Average Remaining Contractual Term	5 years 11 months
Options, Exercisable, Intrinsic Value	$ 82,809
Options, Vested and Expected to Vest, Exercisable, Number	2,379,407
Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	$ 56.90
Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	7 years 1 month
Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	$ 132,963