Share Repurchase Program (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands				2 Months Ended	12 Months Ended		62 Months Ended
	Feb. 10, 2016	May. 29, 2015	Feb. 04, 2015	Feb. 26, 2016	Dec. 31, 2015	Dec. 31, 2014	Feb. 26, 2016
Share Repurchase Program
Increase in authorized amount		$ 500,000	$ 500,000
Authorization effective period		3 years	3 years
Remaining balance under share repurchase program					$ 143,200
Common stock repurchased, shares					4,901	5,743
Common stock repurchased, average price per share					$ 231.81	$ 150.86
Common stock repurchased, value					$ 1,136,139	$ 866,398
Subsequent event [Member]
Share Repurchase Program
Increase in authorized amount	$ 750,000
Cumulative authorized amount	$ 6,300,000
Authorization effective period	3 years
Common stock repurchased, shares				800			52,100
Common stock repurchased, average price per share				$ 247.61			$ 106.76
Common stock repurchased, value				$ 201,600			$ 5,600,000