Leases - Additional Information (Details) - USD ($) $ in Billions	12 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 29, 2018
Lessee, Lease, Description [Line Items]
Typical term of leases (not exceeding)	10 years
Fixed operating lease costs	$ 1.5
Variable lease costs	9.3
Operating leases, rent expense, net		$ 1.3	$ 1.2
Fixed operating lease payments	1.5
Right-of-use assets obtained in exchange for operating and finance lease liabilities	$ 10.5
Weighted-average remaining lease term	10 years 3 months 18 days
Weighted-average discount rate	2.00%
Leases not yet commenced, future payments	$ 1.7
Minimum
Lessee, Lease, Description [Line Items]
Leases not yet commenced, lease term	1 year
Maximum
Lessee, Lease, Description [Line Items]
Leases not yet commenced, lease term	20 years