Components of Net Deferred Taxes (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Deferred tax assets
NOL carryforwards and tax credit carryforwards	$ 72,430	$ 73,833
Stock-based compensation	10,519	10,324
Nondeductible reserves and accruals	6,775	5,137
Amortizable intangibles other than goodwill	3,470	4,138
Capitalized research and development	3,208	5,366
Foreign NOL carryforwards	2,705	4,777
Deferred revenue	1,767	1,567
Depreciation	561	306
Other, net	658	1,222
Deferred Tax Assets, Gross, Total	102,093	106,670
Deferred tax liabilities
Indefinite lived intangibles	(6,415)	(5,554)
Deferred Tax Liabilities, Net	(6,415)	(5,554)
Net deferred tax asset	95,678	101,116
Valuation allowance	(102,093)	(106,670)
Net deferred tax liability	$ (6,415)	$ (5,554)