Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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No definition available.

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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
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Accounting for Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended				9 Months Ended
	Jun. 30, 2016	Feb. 28, 2017	Aug. 31, 2016	Feb. 29, 2016	Nov. 30, 2015	Feb. 28, 2017	Feb. 29, 2016
Stock options
Stock options, additional disclosures
Compensation expense		$ 1.1			$ 0.9	$ 3.4	$ 2.6
Total intrinsic value of stock options exercised						3.3	0.9
Restricted stock
Stock options, additional disclosures
Compensation expense		$ 1.6		$ 1.4		$ 4.2	$ 3.6
Performance-based restricted stock
Stock options, additional disclosures
Granted (in shares)			212,583
Granted (in dollars per share)			$ 24.00
Time-based restricted stock
Stock options, additional disclosures
Granted (in shares)			34,100
Granted (in dollars per share)			$ 24.00
Time-based restricted stock \| Board of Directors
Stock options, additional disclosures
Granted (in shares)	50,000
Granted (in dollars per share)	$ 24.39