Restructuring and Other Charges - Schedule of Restructuring Reserve (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 27, 2020	Sep. 30, 2020
Restructuring Reserve [Roll Forward]
Accrual, beginning balance	$ 9,987	$ 31,086	$ 31,086
Charges to operations, net	345	26,764
Cash disbursements	(6,228)	(25,636)
Other non-cash		164
Foreign exchange impact	50	168
Accrual, ending balance	4,154	16,084	9,987
Accounting Standards Update 2016-02
Restructuring Reserve [Roll Forward]
ASC 842 adoption		(16,462)
Employee Severance and Related Benefits
Restructuring Reserve [Roll Forward]
Accrual, beginning balance	3,992	298	298
Charges to operations, net	162	31,155
Cash disbursements	(3,925)	(21,890)
Other non-cash		0
Foreign exchange impact	33	165
Accrual, ending balance	262	9,728	3,992
Employee Severance and Related Benefits | Accounting Standards Update 2016-02
Restructuring Reserve [Roll Forward]
ASC 842 adoption		0
Facility Closures and Related Costs
Restructuring Reserve [Roll Forward]
Accrual, beginning balance	5,995	30,788	30,788
Charges to operations, net	183	(4,391)
Cash disbursements	(2,303)	(3,746)
Other non-cash		164
Foreign exchange impact	17	3
Accrual, ending balance	$ 3,892	6,356	$ 5,995
Facility Closures and Related Costs | Accounting Standards Update 2016-02
Restructuring Reserve [Roll Forward]
ASC 842 adoption		$ (16,462)