COMPUTATION OF EARNINGS PER COMMON 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	$ 21,228	$ 28,672
Earnings Per Share, Basic and Diluted [Abstract]
Weighted average common shares-basic	38,002	41,619
Dilutive effect of employee equity incentive plans	941	847
Weighted average common shares-diluted	38,943	42,466
Basic earnings per common share	$ 0.56	$ 0.69
Diluted earnings per common share	$ 0.55	$ 0.68
Potentially dilutive securities excluded from diluted earnings per common share because their effect is anti-dilutive	235	547