Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Oct. 01, 2016
Income Statement [Abstract]
Net sales	$ 1,902,573	$ 1,723,311	$ 857,385
Cost of sales	1,071,882	973,042	475,993
Gross profit	830,691	750,269	381,392
Operating expenses:
Research and development	132,586	119,166	81,801
Selling, general and administrative	293,632	292,084	169,138
Gain on business combination	0	(5,416)	0
Impairment and other charges	766	2,916	0
Amortization of intangible assets	10,690	16,024	2,839
Total operating expenses	437,674	424,774	253,778
Income from operations	393,017	325,495	127,614
Other income (expense):
Interest income	1,571	1,090	1,143
Interest expense	(25,847)	(34,362)	(1,346)
Other—net	(7,186)	9,832	(4,515)
Total other expense, net	(31,462)	(23,440)	(4,718)
Income from continuing operations before income taxes	361,555	302,055	122,896
Provision for income taxes	114,195	93,411	35,394
Net income from continuing operations	247,360	208,644	87,502
Loss from discontinued operations, net of income taxes	(2)	(1,522)	0
Net income	$ 247,358	$ 207,122	$ 87,502
Basic net income (loss) per share:
Income per share from continuing operations (in dollars per share)	$ 10.07	$ 8.52	$ 3.62
Loss per share from discontinued operations, net of income taxes (in dollars per share)	0.00	(0.06)	0.00
Net income per share (in dollars per share)	10.07	8.46	3.62
Diluted net income (loss) per share:
Income per share from continuing operations (in dollars per share)	9.95	8.42	3.58
Loss per share from discontinued operations, net of income taxes (in dollars per share)	0.00	(0.06)	0.00
Net income per share (in dollars per share)	$ 9.95	$ 8.36	$ 3.58
Shares used in computation:
Basic (shares)	24,572	24,487	24,142
Diluted (shares)	24,851	24,777	24,415