Leases - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 27, 2020	Jun. 30, 2021	Jun. 27, 2020	Sep. 30, 2020	Feb. 28, 2019
Lessee Lease Description [Line Items]
Payments to be received as sublease income						$ 9,100
Operating lease not commenced, future lease payments	$ 5,700		$ 5,700
Operating right-of-use lease assets	147,431		147,431		$ 149,933
Operating lease, liability	203,133		203,133
Lease Cost
Operating cash flows from operating leases	12,319	$ 12,127	40,396	$ 27,267
Facility Closures and Related Costs
Lessee Lease Description [Line Items]
Operating lease liability, net restructured facilities	4,000		4,000		$ 11,300
Operating right-of-use lease assets	1,500		1,500
Operating lease, liability	5,500		5,500
Lease Cost
Operating cash flows from operating leases	1,200	$ 4,600	7,500	$ 9,100
Facility Closures and Related Costs | Operating Lease Short Term Lease Obligation
Lessee Lease Description [Line Items]
Operating lease, liability	4,000		4,000
Facility Closures and Related Costs | Operating Lease Long Term Lease Obligation
Lessee Lease Description [Line Items]
Operating lease, liability	1,500		1,500
Sublease Income Committed
Lessee Lease Description [Line Items]
Sublease income assumed	$ 1,500		$ 1,500
Minimum
Lessee Lease Description [Line Items]
Operating leases not yet commenced, term	2 years		2 years
Maximum
Lessee Lease Description [Line Items]
Operating leases not yet commenced, term	13 years		13 years