Segment and Geographic Information - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2019	Jun. 29, 2018	Jun. 28, 2019	Jun. 29, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 174,712	$ 178,606	$ 341,146	$ 358,001
Aerospace
Disaggregation of Revenue [Line Items]
Net sales	$ 174,712	$ 178,606	$ 341,146	$ 358,001
Revenue, Net, Percentage	100.00%	100.00%	100.00%	100.00%
Aerospace | Over time
Disaggregation of Revenue [Line Items]
Revenue, Net, Percentage	50.00%	48.00%	47.00%	50.00%
Aerospace | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue, Net, Percentage	50.00%	52.00%	53.00%	50.00%
Military and Defense, other than fuzes [Member] | Aerospace
Disaggregation of Revenue [Line Items]
Net sales	$ 46,758	$ 51,743	$ 82,400	$ 99,499
Missile and Bomb Fuzes [Member] | Aerospace
Disaggregation of Revenue [Line Items]
Net sales	39,113	41,601	96,707	94,586
Commercial Aerospace and Other [Member] | Aerospace
Disaggregation of Revenue [Line Items]
Net sales	88,841	85,262	162,039	163,916
Performance obligations satisfied in previous periods [Member]
Disaggregation of Revenue [Line Items]
Net sales	$ 500	$ 1,400	$ (300)	$ 3,000