Revenue Recognition Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 120,684	$ 118,021	$ 238,308	$ 231,551
Aerospace and Defense [Member]
Disaggregation of Revenue [Line Items]
Revenues	6,988	6,024	14,511	11,127
Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	19,500	22,773	37,656	43,129
Medical [Member]
Disaggregation of Revenue [Line Items]
Revenues	8,973	9,793	18,639	19,034
Telecommunications & IT [Member]
Disaggregation of Revenue [Line Items]
Revenues	4,880	5,525	8,318	10,050
Transportation [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 80,343	$ 73,906	$ 159,184	$ 148,211