Employee Stock Award and Benefit Plans - Deferred Compensation Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Oct. 03, 2015
Share-based Compensation, Allocation and Classification in Financial Statements [Line Items]
Cash surrender value of life insurance contracts	$ 13,995	$ 13,636
Fair value of mutual and money market funds	17,870	14,399
Total assets	31,865	28,035
Total deferred compensation liability, included in:
Other current liabilities	856	1,679
Other long-term liabilities	34,160	28,313
Total deferred compensation liability	35,016	29,992
Gain (loss) on deferred compensation plan investments	5,000	1,700	$ (400)
Death benefit included in gain (Loss) on Deferred Compensation Plan Investments	1,300
Income (loss) to obligation to plan participants	(3,900)	(2,100)	$ 200
Prepaid expenses and other assets
Share-based Compensation, Allocation and Classification in Financial Statements [Line Items]
Total assets	856	1,679
Other assets
Share-based Compensation, Allocation and Classification in Financial Statements [Line Items]
Total assets	$ 31,009	$ 26,356