Business Segment Information - Financial Information by Reportable Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
Segment Reporting Information [Line Items]
Net Revenues	$ 173,475	$ 172,566
Operating Income	13,626	12,848
Depreciation and Amortization Expenses	7,336	6,755
Capital Expenditures	2,952	4,525
Electronic Systems
Segment Reporting Information [Line Items]
Net Revenues	98,120	84,197
Structural Systems
Segment Reporting Information [Line Items]
Net Revenues	75,355	88,369
Operating Segments
Segment Reporting Information [Line Items]
Operating Income	20,512	19,730
Operating Segments | Electronic Systems
Segment Reporting Information [Line Items]
Net Revenues	98,120	84,197
Operating Income	15,122	9,181
Depreciation and Amortization Expenses	3,575	3,502
Capital Expenditures	815	836
Operating Segments | Structural Systems
Segment Reporting Information [Line Items]
Net Revenues	75,355	88,369
Operating Income	5,390	10,549
Depreciation and Amortization Expenses	3,689	3,000
Capital Expenditures	2,137	3,689
Segment Reconciling Items
Segment Reporting Information [Line Items]
Corporate General and Administrative Expenses	(6,886)	(6,882)
Corporate Administration
Segment Reporting Information [Line Items]
Depreciation and Amortization Expenses	72	253
Capital Expenditures	$ 0	$ 0