Leases - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 29, 2019	Dec. 30, 2018	Dec. 31, 2017	Jan. 01, 2017
Lessee Lease Description [Line Items]
Operating lease description	Most leases include one or more options to renew, with renewal terms that can extend the lease term from one to twenty years or more.
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Operating leases	10 years 3 months 18 days	9 years
Rent expense		$ 137.5	$ 120.5	$ 104.8
Sale leaseback accounting during 2019		$ 2.2
Minimum [Member]
Lessee Lease Description [Line Items]
Leases expiration dates	2019
Maximum [Member]
Lessee Lease Description [Line Items]
Leases expiration dates	2034