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Earnings Per Share - Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
Earnings Per Share - Narrative (Details) - USD ($)	Jan. 05, 2018	Nov. 30, 2017	Nov. 30, 2016	Nov. 30, 2017	Nov. 30, 2016	Aug. 02, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Discontinued operations (in dollars per share)		$ (0.01)	$ 0.17	$ 0.51	$ 0.19
Discontinued operations (in dollars per share)		$ (0.01)	$ 0.17	$ 0.50	$ 0.19
Options granted and excluded from the computation of diluted earnings per share (in shares)		500,000	700,000	600,000	600,000
Employee Payroll Taxes Due on Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares acquired (in shares)				300,000
Stock purchased under share buyback, average price per share (in dollars per share)				$ 129.01
Total purchase price of shares repurchased				$ 35,700,000
Share Buyback Program, August 2, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Share buyback program, authorized amount						$ 500,000,000.0
Shares acquired (in shares)				0
Subsequent Event \| Share Buyback Program, August 2, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares acquired (in shares)	0