Consolidated Statements of Comprehensive (Loss) Income (USD $)	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements of Comprehensive (Loss) Income [Abstract]
Net (loss) income	$ (91,511,000)	$ (48,514,000)	$ 12,220,000
Other comprehensive (loss) income, net of tax:
Unrealized gain (loss) on short-term investments	162,000	70,000	(3,000)
Foreign currency translation	(124,000)	(605,000)	1,080,000
Total other comprehensive income (loss), net of tax	38,000	(535,000)	1,077,000
Comprehensive (loss) income	$ (91,473,000)	$ (49,049,000)	$ 13,297,000