Net Income Per Share- Computation of Basic and Diluted Net Income per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Net income	$ 7,437	$ 19,676
Shares used in net income per share computation:
Weighted average shares outstanding - basic	164,431	163,012
Effect of potentially dilutive equivalent shares	2,464	2,821
Weighted average shares outstanding - diluted	166,895	165,833
Net income per share:
Basic (in dollars per share)	$ 0.05	$ 0.12
Diluted (in dollars per share)	$ 0.04	$ 0.12
Anti-dilutive equivalents shares excluded	7,300	9,900