Discontinued Operations - Additional Information (Detail) $ in Thousands, £ in Millions						11 Months Ended	12 Months Ended
	Sep. 29, 2017 GBP (£)	Mar. 28, 2017 USD ($)	May 04, 2016 GBP (£)	Jul. 20, 2015 USD ($)	Jun. 05, 2015 USD ($)	Oct. 02, 2015 USD ($)	Sep. 29, 2017 USD ($)	Sep. 30, 2016 USD ($)	Oct. 02, 2015 USD ($)	[1]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Loss on net assets held for sale						$ 31,154	$ 2,906	$ 8,448	$ 30,792
Sale of discontinued operation						30,156	600	3,654	30,156
Discontinued operation, note receivable								6,681
Gain on sale of discontinued operation						0	793	0	$ 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						2,100	900	800
Environmental Exit Costs, Assets Previously Disposed, Liability for Remediation							100	800
Remediation costs						$ 2,000	$ 1,600	$ 1,500
Small Manufacturing Business
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Sale of discontinued operation		$ 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%
Wallop
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Sale of discontinued operation | £			£ 2.5
Deferred compensation payments | £			£ 9.0
Deferred compensation payment date			May 03, 2019
Payments for earn out | £	£ 5.6
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%
Eclipse
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Sale of discontinued operation					$ 7,900
PA&E
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Sale of discontinued operation				$ 22,300

[1] (Recast)