Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Numerator:
Net income (loss) available to common stockholders	$ (1,892)	$ 1,291	$ (2,364)	$ 1,299
Denominator:
Common shares	88,557	89,073	88,397	88,861
Denominator for basic calculation	88,557	89,073	88,397	88,861
Employee stock options	0	2,187	0	2,335
Employee stock purchase rights	0	355	0	372
Denominator for diluted calculation	88,557	91,615	88,397	91,568
Net income (loss) per share:
Basic	$ (0.02)	$ 0.01	$ (0.03)	$ 0.01
Diluted	$ (0.02)	$ 0.01	$ (0.03)	$ 0.01