Consolidated Statements of Comprehensive (Loss) Income (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Consolidated Statements of Comprehensive (Loss) Income [Abstract]
Net income (loss)	$ 107,359,000	$ (91,511,000)	$ (48,514,000)
Other comprehensive (loss) income, net of tax:
Unrealized gain on short-term investments (net of tax of $22,000, $11,000, and $0, respectively)	34,000	162,000	70,000
Foreign currency translation (loss) gain	(65,000)	(124,000)	(605,000)
Total other comprehensive (loss) income, net of tax	(31,000)	38,000	(535,000)
Comprehensive income (loss)	$ 107,328,000	$ (91,473,000)	$ (49,049,000)