CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Net revenues	$ 212,739	$ 197,402	$ 609,537	$ 558,047
Cost of revenues	102,412	95,238	293,964	260,959
Gross profit	110,327	102,164	315,573	297,088
Operating expenses:
Research, development, and engineering	21,018	20,248	62,328	59,525
Selling, general, and administrative	51,467	45,442	148,071	134,476
Restructuring and other related charges	0	1,868	547	1,868
Total operating expenses	72,485	67,558	210,946	195,869
Operating income	37,842	34,606	104,627	101,219
Interest and other income, net	186	177	59	464
Income before income taxes	38,028	34,783	104,686	101,683
Income tax expense	3,645	6,577	20,212	23,990
Net income	$ 34,383	$ 28,206	$ 84,474	$ 77,693
Earnings per common share:
Basic	$ 0.81	$ 0.68	$ 1.98	$ 1.87
Diluted	$ 0.80	$ 0.66	$ 1.94	$ 1.82
Shares used in computing basic earnings per common share	42,441	41,745	42,647	41,629
Shares used in computing diluted earnings per common share	43,228	42,618	43,554	42,579
Cash dividends declared per common share	$ 0.10	$ 0.10	$ 0.30	$ 0.30