CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Jan. 01, 2017	Dec. 31, 2017	Jan. 01, 2017
Income Statement [Abstract]
Revenues	$ 217,075	$ 176,358	$ 618,186	$ 552,545
Cost of revenues	88,690	72,273	263,001	233,579
Gross profit	128,385	104,085	355,185	318,966
Operating expenses:
Research and development	49,836	38,173	147,027	129,571
Selling, general and administrative	40,689	32,737	127,116	108,968
Total operating expenses	90,525	70,910	274,143	238,539
Operating income	37,860	33,175	81,042	80,427
Interest expense	(6,638)	(4,217)	(20,369)	(12,582)
Interest income and other, net	1,570	407	6,500	3,679
Income before income taxes from continuing operations	32,792	29,365	67,173	71,524
Benefit from (provision for) income taxes	101,033	(4,072)	100,020	(7,451)
Discontinued Operations and Disposal Groups [Abstract]
Gain from divestiture before income taxes	0	1,385	0	1,385
Income tax expense	0	87	0	87
Net income from discontinued operations	0	1,298	0	1,298
Net income (loss)	$ (68,241)	$ 34,735	$ (32,847)	$ 80,273
Net income per share:
Basic net income (loss) per share - continuing operations	$ (0.51)	$ 0.25	$ (0.25)	$ 0.59
Basic net income per share - discontinued operations	0.00	0.01	0.00	0.01
Basic net income (loss) per share	(0.51)	0.26	(0.25)	0.60
Diluted (in dollars per share)	(0.51)	0.24	(0.25)	0.57
Diluted net income per share - discontinued operations	0.00	0.01	0.00	0.01
Diluted net income (loss) per share	$ (0.51)	$ 0.25	$ (0.25)	$ 0.58
Weighted average shares:
Basic (in shares)	132,689	133,846	133,087	133,987
Diluted (in shares)	132,689	137,167	133,087	137,581
Net income (loss) from continuing operations	$ (68,241)	$ 33,437	$ (32,847)	$ 78,975