Summary of Significant Accounting Policies - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Net Revenues	$ 172,566	$ 150,455
Military and Space
Disaggregation of Revenue [Line Items]
Net Revenues	76,661	63,565
Commercial Aerospace
Disaggregation of Revenue [Line Items]
Net Revenues	85,496	73,631
Industrial
Disaggregation of Revenue [Line Items]
Net Revenues	10,409	13,259
Electronic Systems
Disaggregation of Revenue [Line Items]
Net Revenues	84,197	82,409
Electronic Systems | Military and Space
Disaggregation of Revenue [Line Items]
Net Revenues	60,387	51,900
Electronic Systems | Commercial Aerospace
Disaggregation of Revenue [Line Items]
Net Revenues	13,401	17,250
Electronic Systems | Industrial
Disaggregation of Revenue [Line Items]
Net Revenues	10,409	13,259
Structural Systems
Disaggregation of Revenue [Line Items]
Net Revenues	88,369	68,046
Structural Systems | Military and Space
Disaggregation of Revenue [Line Items]
Net Revenues	16,274	11,665
Structural Systems | Commercial Aerospace
Disaggregation of Revenue [Line Items]
Net Revenues	$ 72,095	$ 56,381