Summary of Significant Accounting Policies - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 31, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Change in revenue for the period									$ 91,781
Revenues	$ 186,926	$ 181,101	$ 180,495	$ 172,566	$ 164,183	$ 159,842	$ 154,827	$ 150,455	$ 721,088	$ 629,307	$ 558,183
Percentage of revenues									100.00%	100.00%
Electronic Systems
Disaggregation of Revenue [Line Items]
Change in revenue for the period									$ 22,505
Revenues									$ 360,373	$ 337,868
Percentage of revenues									100.00%	100.00%
Structural Systems
Disaggregation of Revenue [Line Items]
Change in revenue for the period									$ 69,276
Revenues									$ 360,715	$ 291,439
Percentage of revenues									100.00%	100.00%
Military and space
Disaggregation of Revenue [Line Items]
Change in revenue for the period									$ 46,208
Revenues									$ 323,800	$ 277,592
Percentage of revenues									44.90%	44.10%
Military and space | Electronic Systems
Disaggregation of Revenue [Line Items]
Change in revenue for the period									$ 28,526
Revenues									$ 244,245	$ 215,719
Percentage of revenues									67.80%	63.80%
Military and space | Structural Systems
Disaggregation of Revenue [Line Items]
Change in revenue for the period									$ 17,682
Revenues									$ 79,555	$ 61,873
Percentage of revenues									22.10%	21.20%
Commercial aerospace
Disaggregation of Revenue [Line Items]
Change in revenue for the period									$ 44,981
Revenues									$ 348,503	$ 303,522
Percentage of revenues									48.30%	48.20%
Commercial aerospace | Electronic Systems
Disaggregation of Revenue [Line Items]
Change in revenue for the period									$ (6,613)
Revenues									$ 67,343	$ 73,956
Percentage of revenues									18.70%	21.90%
Commercial aerospace | Structural Systems
Disaggregation of Revenue [Line Items]
Change in revenue for the period									$ 51,594
Revenues									$ 281,160	$ 229,566
Percentage of revenues									77.90%	78.80%
Industrial
Disaggregation of Revenue [Line Items]
Change in revenue for the period									$ 592
Revenues									$ 48,785	$ 48,193
Percentage of revenues									6.80%	7.70%
Industrial | Electronic Systems
Disaggregation of Revenue [Line Items]
Change in revenue for the period									$ 592
Revenues									$ 48,785	$ 48,193
Percentage of revenues									13.50%	14.30%