Components of Income Before Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
May 31, 2016	Feb. 29, 2016	Nov. 30, 2015	Aug. 31, 2015	May 31, 2015	Feb. 28, 2015	Nov. 30, 2014	Aug. 31, 2014	Nov. 30, 2014	May 31, 2016	May 31, 2015	May 31, 2014
Schedule of Components of Income Before Income Tax Expense (Benefit) [Line Items]
Domestic										$ 8,991	$ 24,203	$ 30,907
Foreign										(1,204)	447	1,619
Income before income taxes	$ (1,197)	$ 1,492	$ 3,541	$ 3,951	$ 5,646	$ 3,746	$ 7,696	$ 7,562	$ 24,650	$ 7,787	$ 24,650	$ 32,526

Schedule of Components of Income Before Income Tax Expense (Benefit) [Line Items]

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- Definition

The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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- Definition

The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

+ References

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- Definition

Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

+ References

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