Restructuring and Other Charges - Restructuring Accrual Activity (Details) - USD ($)	12 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Oct. 03, 2015
Restructuring Reserve [Roll Forward]
Accrual balance, beginning of period	$ 842,000	$ 0	$ 142,000
Restructuring and other charges	0	7,034,000	1,691,000
Amounts utilized	(842,000)	(6,192,000)	(1,833,000)
Accrual balance, end of period	0	842,000	0
Employee Termination and Severance Costs
Restructuring Reserve [Roll Forward]
Accrual balance, beginning of period	684,000	0	142,000
Restructuring and other charges	0	5,255,000	144,000
Amounts utilized	(684,000)	(4,571,000)	(286,000)
Accrual balance, end of period	0	684,000	0
Lease Obligations and Other Exit Costs
Restructuring Reserve [Roll Forward]
Accrual balance, beginning of period	158,000	0	0
Restructuring and other charges	0	1,779,000	1,547,000
Amounts utilized	(158,000)	(1,621,000)	(1,547,000)
Accrual balance, end of period	$ 0	$ 158,000	$ 0