Discontinued Operations - Additional Information (Detail) $ in Thousands, £ in Millions				12 Months Ended
	Oct. 31, 2018 USD ($)	Mar. 28, 2017 USD ($)	May 04, 2016 GBP (£)	Sep. 28, 2018 USD ($)	Sep. 28, 2018 GBP (£)	Sep. 29, 2017 USD ($)	Sep. 30, 2016 USD ($)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Gain (loss) on assets held for sale and sale of discontinued operations				$ 2,100		$ (2,100)	$ (8,400)
Proceeds from sale of discontinued operations				2,344		600	3,654
Gain on sale of discontinued operation				2,404		793	0
Discontinued Operations Previously Sold Business Unit
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Environmental remediation expense				100		900	$ 800
Environmental Exit Costs, Assets Previously Disposed, Liability for Remediation				100		$ 100
Wallop
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from sale of discontinued operations | £			£ 2.5
Deferred compensation payments | £			£ 9.0
Deferred compensation payment date			May 03, 2019
Payment Received From Deferred Compensation				$ 900
Wallop | Maximum
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Indemnity obligations losses for buyer | £			£ 5.0
Deferred compensation payable acceptable orders percentage			31.00%
Wallop | Minimum
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Deferred compensation payable acceptable orders percentage			26.50%
Wallop | Land and Building
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from sale of discontinued operations | £					£ 1.8
Small Manufacturing Business
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from sale of discontinued operations		$ 600
Discontinued operation, note receivable		2,400
Gain on sale of discontinued operation		$ 800
Discontinued operation, note receivable due date		Mar. 28, 2021
Discontinued operation ,note receivable interest rate		2.05%
Eclipse Electronic Systems Inc | Building | Subsequent Event
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from sale of discontinued operations	$ 4,300