Business Segment Information - Segment Assets (Detail) - USD ($) $ in Thousands	Sep. 28, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total Assets	$ 689,554	$ 644,739
Total Goodwill and Intangibles	240,034	248,149
Operating Segments | Electronic Systems
Segment Reporting Information [Line Items]
Total Assets	418,187	405,743
Total Goodwill and Intangibles	212,808	219,872
Operating Segments | Structural Systems
Segment Reporting Information [Line Items]
Total Assets	254,171	220,993
Total Goodwill and Intangibles	27,226	28,277
Corporate Administration
Segment Reporting Information [Line Items]
Total Assets	$ 17,196	$ 18,003