Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended	12 Months Ended
	Oct. 31, 2015	Jul. 31, 2015	Feb. 29, 2016	Feb. 29, 2016	Feb. 28, 2015	Aug. 31, 2014
Business Acquisition [Line Items]
Consideration attributed to goodwill				$ 30,054
Intronis Inc
Business Acquisition [Line Items]
Business acquisition, purchase price adjustment, increase (decrease) in working capital			$ (200)
Business acquisition, purchase price adjustment, increase (decrease) in deferred tax liabilities			(100)
Business acquisition, aggregate purchase consideration			65,300
Business acquisition, purchase consideration held back for potential indemnification obligations			6,800	6,800
Weighted-average useful lives	7 years
Revenue included in results of operations				9,400
Net loss included in results of operations				1,300
Intronis Inc | Acquired developed technology
Business Acquisition [Line Items]
Weighted-average useful lives	7 years
Consideration attributed to intangible assets	$ 21,500
Intronis Inc | Customer relationships
Business Acquisition [Line Items]
Weighted-average useful lives	7 years
Consideration attributed to intangible assets	$ 11,870
Intronis Inc | Trade name
Business Acquisition [Line Items]
Weighted-average useful lives	4 years
Consideration attributed to intangible assets	$ 300
Other Acquisition
Business Acquisition [Line Items]
Total consideration		$ 1,100
Estimated fair value of contingent consideration		300	100	100
Consideration attributed to intangible assets		700
Consideration attributed to goodwill		$ 300
Other Acquisition | Acquired developed technology
Business Acquisition [Line Items]
Weighted-average useful lives		1 year
Other Acquisition | Customer relationships
Business Acquisition [Line Items]
Weighted-average useful lives		7 years
C2C Systems Limited
Business Acquisition [Line Items]
Estimated fair value of contingent consideration			1,200	$ 1,200	$ 3,000
Acquisition date				Aug. 31, 2014
Contingent cash consideration upon continued employment			$ 4,100	$ 4,100		$ 4,900
Contingent consideration payable description				Upon the attainment of certain billings levels and performance integration targets through August 2017.
Adjustment of contingent consideration, reduction of research and development and sales and marketing expenses				$ 1,900