CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Income Statement [Abstract]
Revenues	$ 235,484	$ 204,398	$ 464,000	$ 401,111
Cost of revenues	91,900	87,636	183,809	174,311
Gross profit	143,584	116,762	280,191	226,800
Operating expenses:
Research and development	55,509	48,742	107,743	97,191
Selling, general and administrative	46,753	44,485	89,748	86,427
Total operating expenses	102,262	93,227	197,491	183,618
Operating income	41,322	23,535	82,700	43,182
Other-than-temporary impairment loss on investment	0	0	(2,000)	0
Interest expense	(7,045)	(6,834)	(14,230)	(13,731)
Interest income and other, net	2,437	1,948	4,108	4,930
Income before income taxes	36,714	18,649	70,578	34,381
Benefit from (provision for) income taxes	(1,214)	31	(4,358)	1,013
Net income	$ 35,500	$ 18,680	$ 66,220	$ 35,394
Net income per share:
Basic (in dollars per share)	$ 0.27	$ 0.14	$ 0.51	$ 0.27
Diluted (in dollars per share)	$ 0.26	$ 0.14	$ 0.49	$ 0.26
Weighted average shares:
Basic (in shares)	129,155	133,269	129,357	133,286
Diluted (in shares)	134,755	136,059	133,957	136,434