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Earnings Per Share - Narrative (Details) - USD ($) $ / shares in Units, shares in Thousands	1 Months Ended	3 Months Ended		6 Months Ended		9 Months Ended
	Jan. 08, 2016	Nov. 30, 2015	Nov. 30, 2014	Nov. 30, 2015	Nov. 30, 2014	Sep. 30, 2015	Aug. 04, 2015	Jan. 13, 2015
Equity, Class of Treasury Stock [Line Items]
Basic earnings per share from discontinued operations (in dollars per share)		$ 2.06		$ 2.01
Diluted earnings per share from discontinued operations (in dollars per share)		$ 2.03		$ 1.98
Basic and diluted earnings per share from discontinued operations (dollars per share)			$ 0.14		$ 0.18
Options granted and excluded from the computation of diluted earnings per share (shares)		300	500	400	600
Shares		2,109		4,474		5,900
Avg. Price per Share (in dollars per share)		$ 85.53		$ 85.59		$ 84.07
Purchase Price		$ 180,390,000		$ 382,918,000		$ 500,000,000
Employee payroll taxes due on restricted stock
Equity, Class of Treasury Stock [Line Items]
Shares	0			200
Avg. Price per Share (in dollars per share)				$ 85.63
Purchase Price		$ 300,000		$ 19,400,000
January 13, 2015
Equity, Class of Treasury Stock [Line Items]
Share buyback program, authorized amount								$ 500,000,000.0
Shares		713		3,078
Avg. Price per Share (in dollars per share)		$ 84.74		$ 85.44
Purchase Price		$ 60,409,000		$ 262,937,000
August 4, 2015
Equity, Class of Treasury Stock [Line Items]
Share buyback program, authorized amount							$ 500,000,000.0
Shares		1,396		1,396
Avg. Price per Share (in dollars per share)		$ 85.94		$ 85.94
Purchase Price		$ 119,981,000		$ 119,981,000