Earnings Per Share - Stock Repurchase Program (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	6 Months Ended	9 Months Ended
	Nov. 30, 2015	Nov. 30, 2015	Sep. 30, 2015
Equity, Class of Treasury Stock [Line Items]
Shares	2,109	4,474	5,900
Avg. Price per Share (in dollars per share)	$ 85.53	$ 85.59	$ 84.07
Purchase Price	$ 180,390	$ 382,918	$ 500,000
January 13, 2015
Equity, Class of Treasury Stock [Line Items]
Shares	713	3,078
Avg. Price per Share (in dollars per share)	$ 84.74	$ 85.44
Purchase Price	$ 60,409	$ 262,937
August 4, 2015
Equity, Class of Treasury Stock [Line Items]
Shares	1,396	1,396
Avg. Price per Share (in dollars per share)	$ 85.94	$ 85.94
Purchase Price	$ 119,981	$ 119,981