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Restructuring (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
Restructuring (Details) $ in Thousands	Jun. 29, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 29, 2018 USD ($)	Jun. 30, 2017 USD ($)	Sep. 29, 2017 USD ($) employee
Restructuring Reserve [Roll Forward]
Restructuring charges	$ 82	$ 0	$ 446	$ 0
2017 Restructuring Plan [Member] [Member]
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated \| employee					80
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance			12,688
Restructuring charges			(23)		$ (12,856)
Cash payments			(11,946)		(168)
Non-cash charges			(583)		0
Restructuring reserve, ending balance	$ 182		$ 182		$ 12,688