Discontinued Operations Income (Loss) Net of Tax (Detail) - USD ($) $ in Thousands	3 Months Ended								11 Months Ended	12 Months Ended
	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Jan. 01, 2016	Oct. 02, 2015	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net Sales									$ 72,402	$ 4,964	$ 22,794	$ 83,231
Operating earnings (loss)									(41,258)	(8,707)	(15,578)	(45,231)
Tax expense (benefit)									(4,205)	(1,396)	(312)	(4,912)
Income (loss) from discontinued operations	$ (1,126)	$ (815)	$ (34)	$ (5,336)	$ 227	$ (8,690)	$ (2,023)	$ (4,780)	(37,053)	(7,311)	(15,266)	(40,319)	[1]
Included in Operating Earnings (Loss):
Gain (loss) on net assets held for sale									(31,154)	(2,906)	(8,448)	(30,792)	[1]
Gain (loss) on sale of discontinued operations									0	793	0	0	[1]
Avionics & Controls
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net Sales									40,835	4,964	17,572	47,603
Operating earnings (loss)									(24,591)	(447)	1,350	(24,004)
Tax expense (benefit)									(3,002)	(470)	1,487	(2,948)
Income (loss) from discontinued operations									(21,589)	23	(137)	(21,056)
Included in Operating Earnings (Loss):
Gain (loss) on net assets held for sale									(18,864)	320	(2,457)	(16,763)
Gain (loss) on sale of discontinued operations										793
Sensors & Systems
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net Sales									18,684	0	0	21,221
Operating earnings (loss)									3,041	894	(379)	3,458
Tax expense (benefit)									626	0	(83)	814
Income (loss) from discontinued operations									2,415	894	(296)	2,644
Included in Operating Earnings (Loss):
Gain (loss) on net assets held for sale									(229)	0	0	(622)
Gain (loss) on sale of discontinued operations										0
Advanced Materials
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net Sales									12,883	0	5,222	14,407
Operating earnings (loss)									(17,588)	(8,259)	(15,761)	(22,424)
Tax expense (benefit)									(1,104)	(614)	(1,448)	(2,456)
Income (loss) from discontinued operations									(16,484)	(7,645)	(14,313)	(19,968)
Included in Operating Earnings (Loss):
Gain (loss) on net assets held for sale									(12,061)	(3,226)	(5,991)	(13,407)
Gain (loss) on sale of discontinued operations										0
Other
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net Sales									0	0	0	0
Operating earnings (loss)									(2,120)	(895)	(788)	(2,261)
Tax expense (benefit)									(725)	(312)	(268)	(322)
Income (loss) from discontinued operations									(1,395)	(583)	(520)	(1,939)
Included in Operating Earnings (Loss):
Gain (loss) on net assets held for sale									$ 0	0	$ 0	$ 0
Gain (loss) on sale of discontinued operations										$ 0

[1] (Recast)