Earnings Per Share (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended		55 Months Ended
	Aug. 07, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Aug. 07, 2015
Earnings Per Share
Common stock repurchased, shares		1,987	1,873	2,637	2,022
Common stock repurchased, average price per share		$ 221.50	$ 148.21	$ 218.05	$ 148.21
Common stock repurchased, value		$ 440,129	$ 277,561	$ 574,932	$ 299,625
Subsequent Event [Member]
Earnings Per Share
Common stock repurchased, shares	200					49,200
Common stock repurchased, average price per share	$ 231.47					$ 98.57
Common stock repurchased, value	$ 57,200					$ 4,900,000