Summary of Significant Accounting Policies - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 173,475	$ 172,566
Military and space
Disaggregation of Revenue [Line Items]
Revenue	100,820	76,661
Commercial Aerospace
Disaggregation of Revenue [Line Items]
Revenue	62,525	85,496
Industrial
Disaggregation of Revenue [Line Items]
Revenue	10,130	10,409
Electronic Systems
Disaggregation of Revenue [Line Items]
Revenue	98,120	84,197
Electronic Systems | Military and space
Disaggregation of Revenue [Line Items]
Revenue	73,238	60,387
Electronic Systems | Commercial Aerospace
Disaggregation of Revenue [Line Items]
Revenue	14,752	13,401
Electronic Systems | Industrial
Disaggregation of Revenue [Line Items]
Revenue	10,130	10,409
Structural Systems
Disaggregation of Revenue [Line Items]
Revenue	75,355	88,369
Structural Systems | Military and space
Disaggregation of Revenue [Line Items]
Revenue	27,582	16,274
Structural Systems | Commercial Aerospace
Disaggregation of Revenue [Line Items]
Revenue	$ 47,773	$ 72,095