Discontinued Operations Assets and Liabilities Held for Sale (Detail) - USD ($) $ in Thousands	Mar. 30, 2018	Sep. 29, 2017
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Other current assets	$ 4,300	$ 6,501
Current Assets of Businesses Held for Sale	4,300	6,501
Net property, plant and equipment	5,262	5,262
Other assets	8,856	8,072
Non-Current Assets of Businesses Held for Sale	14,118	13,334
Accounts payable	30	138
Accrued liabilities	4,499	7,046
Current Liabilities of Businesses Held for Sale	4,529	7,184
Deferred income tax liabilities	2,787	1,404
Other liabilities	320	320
Non-Current Liabilities of Businesses Held for Sale	3,107	1,724
Net Assets of Businesses Held for Sale	10,782	10,927
Avionics & Controls
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Other current assets	0	0
Current Assets of Businesses Held for Sale	0	0
Net property, plant and equipment	5,262	5,262
Other assets	0	0
Non-Current Assets of Businesses Held for Sale	5,262	5,262
Accounts payable	0	0
Accrued liabilities	0	0
Current Liabilities of Businesses Held for Sale	0	0
Deferred income tax liabilities	0	0
Other liabilities	0	0
Non-Current Liabilities of Businesses Held for Sale	0	0
Net Assets of Businesses Held for Sale	5,262	5,262
Sensors & Systems
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Other current assets	0	0
Current Assets of Businesses Held for Sale	0	0
Net property, plant and equipment	0	0
Other assets	0	0
Non-Current Assets of Businesses Held for Sale	0	0
Accounts payable	0	0
Accrued liabilities	0	0
Current Liabilities of Businesses Held for Sale	0	0
Deferred income tax liabilities	0	0
Other liabilities	0	0
Non-Current Liabilities of Businesses Held for Sale	0	0
Net Assets of Businesses Held for Sale	0	0
Advanced Materials
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Other current assets	4,300	6,501
Current Assets of Businesses Held for Sale	4,300	6,501
Net property, plant and equipment	0	0
Other assets	8,856	8,072
Non-Current Assets of Businesses Held for Sale	8,856	8,072
Accounts payable	30	138
Accrued liabilities	4,499	7,046
Current Liabilities of Businesses Held for Sale	4,529	7,184
Deferred income tax liabilities	2,787	1,404
Other liabilities	320	320
Non-Current Liabilities of Businesses Held for Sale	3,107	1,724
Net Assets of Businesses Held for Sale	$ 5,520	$ 5,665