Reconciliation of Assets from Segment to Consolidated (Detail) - USD ($) $ in Thousands		12 Months Ended
		Sep. 28, 2018	Sep. 29, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Capital Expenditures		$ 53,292	$ 58,040	$ 68,472
Depreciation and amortization		106,724	103,770	100,258
Identifiable Assets		3,036,917	3,120,013	3,029,390
Discontinued Operations
Segment Reporting Information [Line Items]
Depreciation and amortization		0	0	12
Identifiable Assets		6,950	21,192	29,488
Operating Segments | Avionics & Controls
Segment Reporting Information [Line Items]
Capital Expenditures		9,805	19,315	36,423
Depreciation and amortization		41,668	40,853	38,909
Identifiable Assets		1,346,689	1,382,176	1,302,441
Operating Segments | Sensors & Systems
Segment Reporting Information [Line Items]
Capital Expenditures	[1]	24,264	22,804	14,319
Depreciation and amortization		44,681	41,722	40,399
Identifiable Assets		1,131,842	1,139,676	1,140,017
Operating Segments | Advanced Materials
Segment Reporting Information [Line Items]
Capital Expenditures	[2]	18,452	14,247	15,868
Depreciation and amortization		17,625	18,559	18,691
Identifiable Assets		455,263	504,965	498,442
Corporate Non Segment
Segment Reporting Information [Line Items]
Capital Expenditures		771	1,674	1,862
Depreciation and amortization		2,750	2,636	2,247
Identifiable Assets	[3]	$ 96,173	$ 72,004	$ 59,002

[1] Excludes capital expenditures accounted for as a capitalized lease obligation of $0.5 million and $8.0 million in fiscal 2017 and 2016, respectively.

[2] Excludes capital expenditures accounted for as a capitalized lease obligation of $0.1 million, $3.5 million and $3.3 million in fiscal 2018, 2017 and 2016, respectively.

[3] Primarily cash and deferred tax assets (see Note 10).