Earnings Per Share - Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 06, 2018	Feb. 28, 2018	Feb. 28, 2017	Feb. 28, 2018	Feb. 28, 2017	Aug. 02, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Basic earnings from discontinued operations (in dollars per share)		$ 0.06	$ 0.01	$ 0.57	$ 0.20
Diluted earnings from discontinued operations (in dollars per share)		$ 0.05	$ 0.01	$ 0.55	$ 0.20
Options granted and excluded from the computation of diluted earnings per share (in shares)		1,000,000	300,000	800,000	500,000
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)				$ 130.00
Total purchase price of shares repurchased				$ 37,000,000
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
Share Buyback Program, August 2, 2016 | Subsequent Event
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares acquired (in shares)	0