Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Feb. 28, 2017	Feb. 29, 2016	Feb. 28, 2015	Feb. 28, 2014
Income Tax Examination [Line Items]
Valuation allowance	$ (77,513,000)	$ (73,399,000)
Increase in valuation allowance	4,100,000
Excess tax benefits from equity compensation plans	1,909,000	3,788,000	$ 8,947,000
Federal net operating loss carryforwards	15,900,000
State net operating loss carryforwards	$ 6,800,000
Federal operating losses expiration, beginning period	2019
Federal operating losses expiration, ending period	2035
State operating losses expiration, beginning period	2028
State operating losses expiration, ending period	2035
Foreign net operating loss carryforwards	$ 9,900,000
Operating losses can be carried forward indefinitely	$ 9,600,000
Remaining foreign net operating losses expiration period	2019
Research and development credit carryforwards	$ 5,436,000	6,484,000
Federal research and development credit expiration beginning period	2029
Other state research and development credit expiration beginning period	2021
Undistributed earnings of its foreign subsidiaries	$ 6,700,000
Total unrecognized tax benefits	9,957,000	6,388,000	5,322,000	$ 4,980,000
Unrecognized tax benefits that, if recognized, would affect our effective tax rate	5,100,000	2,600,000	4,300,000
Interest and penalties recorded in the consolidated statements of operations	100,000	0	100,000
Accrued interest and penalties recorded on the consolidated balance sheets	900,000	800,000
Federal
Income Tax Examination [Line Items]
Research and development credit carryforwards	600,000
California
Income Tax Examination [Line Items]
Research and development credit carryforwards	6,500,000
Enterprise zone tax credit carryforwards	$ 300,000
Tax credit expiration beginning period	2024
Other state
Income Tax Examination [Line Items]
Research and development credit carryforwards	$ 300,000
Additional Paid-In Capital
Income Tax Examination [Line Items]
Excess tax benefits from equity compensation plans	$ 1,909,000	$ 3,788,000	$ 8,947,000