Business Segment Information - Segment Assets (Detail) - USD ($) $ in Thousands	Oct. 01, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total Assets	$ 520,982	$ 557,081
Total Goodwill and Intangibles	186,389	212,461
Operating Segments | Structural Systems
Segment Reporting Information [Line Items]
Total Assets	177,831	179,134
Total Goodwill and Intangibles	4,025	4,866
Operating Segments | Electronic Systems
Segment Reporting Information [Line Items]
Total Assets	329,606	363,227
Total Goodwill and Intangibles	182,364	207,595
Corporate Administration
Segment Reporting Information [Line Items]
Total Assets	$ 13,545	$ 14,720