Earnings Per Share (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	2 Months Ended	12 Months Ended		62 Months Ended
	Feb. 26, 2016	Dec. 31, 2015	Dec. 31, 2014	Feb. 26, 2016
Earnings Per Share
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]
Earnings Per Share
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