CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data	3 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Net revenues	$ 175,600	$ 170,685
Cost of revenues	81,542	81,237
Gross profit	94,058	89,448
Operating expenses:
Research, development and engineering	16,906	14,901
Selling, general and administrative	42,116	38,686
Total operating expenses	59,022	53,587
Operating income	35,036	35,861
Interest and other income (expense), net	641	(382)
Income before income taxes	35,677	35,479
Income tax expense	8,946	9,533
Net income	$ 26,731	$ 25,946
Earnings per common share:
Basic	$ 0.57	$ 0.54
Diluted	$ 0.56	$ 0.52
Shares used in computing basic earnings per common share	46,688	48,128
Shares used in computing diluted earnings per common share	48,060	49,714
Cash dividends declared per common share	$ 0.05	$ 0.05