Nature of Operations and Summary of Significant Accounting Policies (Narrative) (Details) $ in Thousands	12 Months Ended
	Sep. 29, 2019 USD ($) restaurant	Sep. 30, 2018 USD ($) restaurant	Oct. 01, 2017 USD ($) restaurant	Oct. 02, 2016	Oct. 01, 2018 USD ($)	Dec. 19, 2017 restaurant
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants | restaurant	2,243	2,237	2,251
Number of weeks per fiscal year	52	52	52	53
Depreciation	$ 55,200	$ 59,400	$ 67,400
Amounts recognized on unredeemed gift card balances	500	600	500
General liability and workers' comp estimated claims to be paid by insurance providers	$ 3,600	3,700
Contractual contributions	5.00%
Marketing Expense	$ 2,000	6,200	500
Marketing and advertising expense	19,000	28,800	36,500
Cumulative effect of new accounting principle in period of adoption					$ (37,330)
Deferred tax assets	85,564	62,140
Pension cost reclassification	1,484	1,833	$ 3,360
Other Assets
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Cash surrender value of life insurance	$ 112,800	$ 109,900
Minimum
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment assigned lives	1 year
Maximum
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment assigned lives	35 years
Qdoba Brand Restaurant Operations
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants | restaurant						700
Franchise Fees | Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Cumulative effect of new accounting principle in period of adoption	$ 50,300
Contract liabilities current	5,000
Contract liabilities noncurrent	45,300
Deferred tax assets	$ 13,000