Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended				12 Months Ended
	Mar. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Aug. 31, 2014	Feb. 28, 2017	Feb. 29, 2016
Business Acquisition [Line Items]
Goodwill					$ 69,795	$ 69,595
Consideration attributed to goodwill					409
Sookasa Inc.
Business Acquisition [Line Items]
Business acquisition, aggregate purchase consideration	$ 300
Business acquisition, issuance of common stock to acquire Sookasa Inc. (in shares)	10,000
Total consideration	$ 400
Goodwill	$ 400
Intronis Inc
Business Acquisition [Line Items]
Business acquisition, aggregate purchase consideration		$ 65,300
Goodwill		$ 29,718
Business acquisition, purchase consideration held back for potential indemnification obligations					6,700
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		200
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					700	$ 1,200
Acquisition date				Aug. 31, 2014
Contingent cash consideration upon continued employment				$ 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					500	$ 1,900
Business combination, contingent consideration arrangements, agreed amount to be paid					1,250
Business combination, contingent consideration, amount held for potential indemnification claims					$ 500