Discontinued Operations and Sale of Assets Held for Sale (Details) - USD ($)		3 Months Ended	12 Months Ended
	Apr. 27, 2018	Dec. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Oct. 01, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on divestiture of discontinued operations		$ 2,000
Net sales			$ 0	$ 26,996,000
Cost of sales			0	19,353,000
Operating expenses			0	9,002,000
Other expense			0	220,000
Loss from discontinued operations			0	(1,579,000)
Loss on disposal of discontinued operations			(2,000)	0
Total loss on discontinued operations			(2,000)	(1,579,000)
Income tax expense (benefit)			0	(57,000)
Net loss from discontinued operations			$ (2,000)	(1,522,000)	$ 0
Non cash impairment charge to reduce carrying value of the acquired entities to fair value				2,900,000
Sale of entities acquired in the Rofin acquisition	$ 6,300,000
Net loss from sale of entities acquired in the Rofin acquisition				300,000
September 30, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				35,262,000
Liabilities				6,004,000
September 30, 2017 | Cash
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				33,000
September 30, 2017 | Accounts receivable
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				6,931,000
September 30, 2017 | Inventories
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				5,586,000
September 30, 2017 | Prepaid expenses and other assets
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				607,000
September 30, 2017 | Property and equipment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				10,705,000
September 30, 2017 | Intangible assets
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				11,400,000
September 30, 2017 | Accounts payable
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Liabilities				1,129,000
September 30, 2017 | Other current liabilities:
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Liabilities				4,875,000
September 30, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				8,986,000
Liabilities				1,017,000
September 30, 2017 | Accounts receivable
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				1,668,000
September 30, 2017 | Inventories
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				5,202,000
September 30, 2017 | Prepaid expenses and other assets
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				472,000
September 30, 2017 | Property and equipment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				457,000
September 30, 2017 | Intangible assets
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				1,187,000
September 30, 2017 | Accounts payable
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Liabilities				189,000
September 30, 2017 | Other current liabilities:
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Liabilities				$ 828,000