Basic and Diluted Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator:
Net income (loss)	$ (4,998)	$ 7,194	$ (17,203)	$ (29,856)
Weighted-average shares outstanding:
Basic (in shares)	46,590	45,767	46,471	45,660
Assumed conversion of employee stock grants (in shares)	0	217	0	0
Assumed conversion of warrants (in shares)	0	4,020	0	0
Diluted (in shares)	46,590	50,004	46,471	45,660
Net income (loss) per basic share (in usd per share)	$ (0.11)	$ 0.16	$ (0.37)	$ (0.65)
Net income (loss) per diluted share (in usd per share)	$ (0.11)	$ 0.14	$ (0.37)	$ (0.65)
Assumed conversion of employee stock grants
Common stock equivalents that could potentially dilute net income per basic share in the future, but were not included in the computation of diluted earnings per share because the impact would have been antidilutive
Common stock equivalents (in shares)	2,596	3,942	2,322	3,507
Assumed conversion of warrants
Common stock equivalents that could potentially dilute net income per basic share in the future, but were not included in the computation of diluted earnings per share because the impact would have been antidilutive
Common stock equivalents (in shares)	5,771	0	5,380	5,305