CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
Net revenues	$ 216,662	$ 202,818
Cost of revenues	101,952	97,186
Gross profit	114,710	105,632
Operating expenses:
Research, development, and engineering	22,520	20,863
Selling, general, and administrative	56,429	48,097
Gain from litigation settlement	(2,000)	0
Restructuring and other related charges	0	723
Total operating expenses	76,949	69,683
Operating income	37,761	35,949
Interest and other income (expense), net	1,020	(486)
Income before income taxes	38,781	35,463
Income tax expense	10,109	8,510
Net income	$ 28,672	$ 26,953
Earnings per common share:
Basic	$ 0.69	$ 0.63
Diluted	$ 0.68	$ 0.62
Shares used in computing basic earnings per common share	41,619	42,692
Shares used in computing diluted earnings per common share	42,466	43,650
Cash dividends declared per common share	$ 0.15	$ 0.10