Revenue Recognition Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 115,651	$ 118,859	$ 353,959	$ 350,410
Aerospace and Defense [Member]
Disaggregation of Revenue [Line Items]
Revenues	9,025	5,692	23,536	16,819
Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	19,750	22,675	57,406	65,804
Medical [Member]
Disaggregation of Revenue [Line Items]
Revenues	10,537	10,259	29,176	29,293
Telecommunications & IT [Member]
Disaggregation of Revenue [Line Items]
Revenues	4,780	5,049	13,098	15,099
Transportation [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 71,559	$ 75,184	$ 230,743	$ 223,395