Goodwill and Intangible Assets - Changes in Net Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
May 31, 2018	Feb. 28, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill, Beginning balance	$ 70,603	$ 70,603
Goodwill impairment	0	0
Goodwill, Ending balance	$ 70,603	$ 70,603

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration