CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Net revenues	$ 856,907	$ 865,010	$ 818,607
Cost of revenues	422,233	403,391	391,979
Gross profit	434,674	461,619	426,628
Operating expenses:
Research, development, and engineering	90,408	91,627	84,781
Selling, general, and administrative	221,299	229,569	201,176
Gain from litigation settlements	(1,234)	(8,662)	0
Restructuring and other related charges	16,160	0	547
Total operating expenses	326,633	312,534	286,504
Operating income	108,041	149,085	140,124
Interest expense	(25,149)	(241)	(238)
Other non-operating income and (expense), net	(716)	(3,593)	1,253
Income before income taxes	82,176	145,251	141,139
Income tax expense	13,784	32,950	28,722
Net income	$ 68,392	$ 112,301	$ 112,417
Earnings Per Share, Basic [Abstract]
Basic (in dollars per share)	$ 2.00	$ 2.69	$ 2.65
Earnings Per Share, Diluted [Abstract]
Diluted (in dollars per share)	$ 1.96	$ 2.63	$ 2.59
Shares used in basic per share calculations	34,127	41,723	42,452
Shares used in diluted per share calculations	34,938	42,643	43,364
Cash dividends declared per common share (in dollars per share)	$ 0.60	$ 0.60	$ 0.40