Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Feb. 28, 2017	Feb. 28, 2017
Income Tax Disclosure [Abstract]
Unrecognized tax benefits, period increase (decrease)	$ 0.4	$ (1.3)
Unrecognized tax benefits, increase (decrease) in accrued interest	$ 0.1	$ (0.1)

Amount of increase (decrease) in unrecognized tax benefits attributable to uncertain tax positions taken in tax returns.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=65882285&loc=SL6600010-109319

Name:	us-gaap_UnrecognizedTaxBenefitsPeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration