Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Oct. 02, 2020 USD ($) market segment	Sep. 27, 2019 USD ($)	Sep. 28, 2019 USD ($)
Description Of Business And Basis Of Presentation [Line Items]
Number of reportable operating segments | segment	1
Number of primary markets | market	3
Operating lease liability	$ 39,438
Operating lease right of use asset	33,307
Operating Lease and Finance Lease, Right-Of-Use Asset	66,434	$ 40,442
Operating Lease and Finance Lease, Liability	69,800	30,590
Finance Lease, Right-of-Use Asset	33,127
Finance Lease, Liability	$ 30,362
Minimum
Description Of Business And Basis Of Presentation [Line Items]
Definite-lived intangible asset useful life	5 years
Maximum
Description Of Business And Basis Of Presentation [Line Items]
Definite-lived intangible asset useful life	14 years
Accounting Standards Update 2016-02
Description Of Business And Basis Of Presentation [Line Items]
Operating lease liability			$ 43,600
Operating lease right of use asset			37,700
Operating Lease and Finance Lease, Right-Of-Use Asset			37,100
Operating Lease and Finance Lease, Liability			39,000
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets			1,900
Other Liabilities			5,900
Finance Lease, Right-of-Use Asset			35,700
Finance Lease, Liability			$ 31,800
Disposal Group, Not Discontinued Operations | LR4
Description Of Business And Basis Of Presentation [Line Items]
Gain (loss) on disposal		$ 34,300