CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2010
Net revenues	$ 183,236	$ 181,585	$ 535,784	$ 510,525
Cost of revenues	87,024	85,777	246,548	239,310
Gross profit	96,212	95,808	289,236	271,215
Operating expenses:
Research, development and engineering	16,829	16,373	51,386	46,480
Selling, general and administrative	41,976	43,319	128,510	118,747
Restructuring and other related charges	0	(428)	0	(428)
Total operating expenses	58,805	59,264	179,896	164,799
Operating income	37,407	36,544	109,340	106,416
Interest and other income (expense), net	406	(20)	989	615
Income before income taxes	37,813	36,524	110,329	107,031
Income tax expense	6,915	4,972	25,179	24,104
Net income	$ 30,898	$ 31,552	$ 85,150	$ 82,927
Earnings per common share:
Basic	$ 0.73	$ 0.66	$ 1.91	$ 1.74
Diluted	$ 0.71	$ 0.64	$ 1.86	$ 1.68
Shares used in computing basic earnings per common share	42,541	47,649	44,623	47,621
Shares used in computing diluted earnings per common share	43,640	49,431	45,857	49,271
Cash dividends declared per common share	$ 0.05	$ 0.05	$ 0.15	$ 0.15