Revenue Recognition Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 117,625	$ 113,530
Aerospace and Defense [Member]
Disaggregation of Revenue [Line Items]
Revenues	7,523	5,103
Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	18,156	20,356
Medical [Member]
Disaggregation of Revenue [Line Items]
Revenues	9,666	9,241
Telecommunications & IT [Member]
Disaggregation of Revenue [Line Items]
Revenues	3,438	4,525
Transportation [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 78,842	$ 74,305