Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Nov. 30, 2018	Aug. 31, 2018	Nov. 30, 2017	Nov. 30, 2018	Nov. 30, 2017	May 31, 2018
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 28.8			$ 28.8		$ 26.9
Provisions tax expense (benefit)	$ 0.0	$ 3.3
Effective tax rate	24.20%		33.30%	18.90%	29.80%

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(2))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration