Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 27, 2020	Jun. 30, 2021	Jun. 27, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 51,203	$ 34,678	$ 183,980	$ 77,289
Other comprehensive income, net of tax:
Hedge loss arising during the period, net of tax of $0 million and $0.4 million in the third quarter of 2021 and 2020, respectively, and $0 million and $1.2 million in the first nine months of 2021 and 2020, respectively	(1,797)	(1,148)	(1,559)	(3,790)
Foreign currency translation adjustment, net of tax of $0 for each period	6,457	3,089	10,581	2,677
Unrealized gain (loss) on marketable securities, net of tax of $0 for each period	0	822	(307)	278
Amortization of net actuarial pension loss included in net income, net of tax of $0.3 million and $0.3 million in the third quarter of 2021 and 2020, respectively, and $0.9 million and $0.8 million in the first nine months of 2021 and 2020, respectively	738	673	2,214	2,027
Change in unamortized pension loss during the period related to changes in foreign currency	(291)	(152)	(385)	(693)
Other comprehensive income	5,107	3,284	10,544	499
Comprehensive income	$ 56,310	$ 37,962	$ 194,524	$ 77,788