Income Taxes - Schedule of temporary differences comprising the net deferred income tax liability (Details) - USD ($) $ in Thousands	Oct. 03, 2021	Sep. 27, 2020
Deferred Tax Assets:
State taxes	$ 1,342	$ 1,146
Reserves and contingent liabilities	6,662	6,262
Accounts receivable including the allowance for doubtful accounts	5,917	6,283
Accrued liabilities	41,657	28,223
Lease liabilities, operating leases	60,181	66,941
Stock-based compensation	3,560	5,905
Loss carry-forwards	54,825	43,475
Valuation allowance	(13,040)	(24,395)
Total deferred tax assets	161,104	133,840
Deferred Tax Liabilities:
Unbilled revenue	(5,595)	(14,451)
Prepaid expense	(8,136)	(5,967)
Right-of-use assets, operating leases	(60,181)	(66,941)
Intangibles	(40,121)	(29,130)
Undistributed earnings	(3,136)	0
Property and equipment	(85)	(1,615)
Total deferred tax liabilities	(117,254)	(118,104)
Net deferred tax assets	$ 43,850	$ 15,736