Income Taxes - Components of Provision (Benefit) for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Oct. 02, 2020	Sep. 27, 2019	Sep. 28, 2018
Current:
Federal	$ (834)	$ 70	$ (6,876)
State	48	36	(160)
Foreign	1,958	876	1,642
Current provision (benefit)	1,172	982	(5,394)
Deferred:
Federal	(8,635)	(21,560)	75,428
State	(22,613)	12,907	(15,526)
Foreign	9,686	(41,108)	(24,652)
Change in valuation allowance	24,906	9,424	(51,329)
Deferred provision (benefit)	3,344	(40,337)	(16,079)
Total provision (benefit)	$ 4,516	$ (39,355)	$ (21,473)