Business Segment Information - Segment Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total Assets	$ 790,429	$ 644,739
Goodwill and Intangibles	309,279	248,149
Operating Segments | Electronic Systems
Segment Reporting Information [Line Items]
Total Assets	411,981	405,743
Goodwill and Intangibles	210,453	219,872
Operating Segments | Structural Systems
Segment Reporting Information [Line Items]
Total Assets	328,718	220,993
Goodwill and Intangibles	98,826	28,277
Corporate Administration
Segment Reporting Information [Line Items]
Total Assets	$ 49,730	$ 18,003