Summary of Significant Accounting Policies - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Disaggregation of Revenue [Line Items]
Net Revenues	$ 154,827	$ 140,938	$ 305,282	$ 277,235
Corporate Segment
Disaggregation of Revenue [Line Items]
Net Revenues	154,827	140,938	305,282	277,235
Corporate Segment | Military and Space
Disaggregation of Revenue [Line Items]
Net Revenues	70,326	70,174	136,681	134,115
Corporate Segment | Commercial Aerospace
Disaggregation of Revenue [Line Items]
Net Revenues	71,844	55,730	142,676	113,091
Corporate Segment | Industrial
Disaggregation of Revenue [Line Items]
Net Revenues	12,657	15,034	25,925	30,029
Structural Systems
Disaggregation of Revenue [Line Items]
Net Revenues	70,325	59,112	138,372	116,687
Structural Systems | Military and Space
Disaggregation of Revenue [Line Items]
Net Revenues	15,958	15,476	29,780	29,780
Structural Systems | Commercial Aerospace
Disaggregation of Revenue [Line Items]
Net Revenues	54,367	43,636	108,592	86,907
Electronic Systems
Disaggregation of Revenue [Line Items]
Net Revenues	84,502	81,826	166,910	160,548
Electronic Systems | Military and Space
Disaggregation of Revenue [Line Items]
Net Revenues	54,368	54,698	106,901	104,335
Electronic Systems | Commercial Aerospace
Disaggregation of Revenue [Line Items]
Net Revenues	17,477	12,094	34,084	26,184
Electronic Systems | Industrial
Disaggregation of Revenue [Line Items]
Net Revenues	$ 12,657	$ 15,034	$ 25,925	$ 30,029