Significant Accounting Policies - Property and Equipment (Details) $ in Thousands	12 Months Ended
	Oct. 01, 2016 USD ($) customers weeks	Oct. 03, 2015 USD ($) customers weeks	Sep. 27, 2014 weeks
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 381,151	$ 337,600
Accumulated depreciation and amortization	(253,708)	(235,155)
Property and equipment, net	$ 127,443	$ 102,445
Fiscal period, number of weeks | weeks	52	53	52
Land
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 7,523	$ 6,132
Building and improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	85,908	69,970
Equipment, furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	248,741	230,208
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 38,979	$ 31,290
Minimum | Building and improvements
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Minimum | Equipment, furniture and fixtures
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Minimum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful lives	1 year
Maximum | Building and improvements
Property, Plant and Equipment [Line Items]
Estimated useful lives	40 years
Maximum | Equipment, furniture and fixtures
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Maximum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful lives	15 years
Accounts Receivable
Property, Plant and Equipment [Line Items]
Number of Customers, Concentration Risk | customers	2	1