Balance Sheet Information - Marketable Securities (Detail) - USD ($) $ in Thousands	3 Months Ended
May 31, 2016	Feb. 29, 2016
Schedule of Available-for-sale Securities [Line Items]
Marketable securities, Amortized Cost	$ 39,010	$ 36,014
Marketable securities, Gross Unrealized Gains	773	432
Marketable securities, Gross Unrealized Losses	(56)	(52)
Marketable securities, Fair Value	39,727	36,394
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Marketable securities, Amortized Cost	4,849	4,717
Marketable securities, Gross Unrealized Gains	19	9
Marketable securities, Gross Unrealized Losses		(3)
Marketable securities, Fair Value	4,868	4,723
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Marketable securities, Amortized Cost	20,910	19,135
Marketable securities, Gross Unrealized Gains	26	11
Marketable securities, Gross Unrealized Losses	(20)	(22)
Marketable securities, Fair Value	20,916	19,124
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Marketable securities, Amortized Cost	1,596	3,095
Marketable securities, Gross Unrealized Gains	709	380
Marketable securities, Fair Value	2,305	3,475
Available-for-sale securities, gross realized gains	400
Foreign government bonds
Schedule of Available-for-sale Securities [Line Items]
Marketable securities, Amortized Cost	201	205
Marketable securities, Fair Value	201	205
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Marketable securities, Amortized Cost	1,812	2,341
Marketable securities, Gross Unrealized Gains	1
Marketable securities, Gross Unrealized Losses	(5)	(13)
Marketable securities, Fair Value	1,808	2,328
U.S. government agency securities
Schedule of Available-for-sale Securities [Line Items]
Marketable securities, Amortized Cost	6,189	2,242
Marketable securities, Gross Unrealized Gains	6	6
Marketable securities, Gross Unrealized Losses	(29)	(14)
Marketable securities, Fair Value	6,166	2,234
U.S. government notes
Schedule of Available-for-sale Securities [Line Items]
Marketable securities, Amortized Cost	3,453	4,279
Marketable securities, Gross Unrealized Gains	12	26
Marketable securities, Gross Unrealized Losses	(2)
Marketable securities, Fair Value	$ 3,463	$ 4,305

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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