Organization and Basis of Presentation Schedule of Revenue by Major Customer (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 164,877	$ 167,077	$ 160,617	$ 155,199	$ 163,255	$ 158,443	$ 159,447	$ 163,037	$ 647,770	$ 644,182	$ 543,013
Government Contracts Concentration Risk [Member] | Sales Revenue, Segment [Member]
Disaggregation of Revenue [Line Items]
Revenues									$ 86,644	$ 94,822	$ 92,192
Concentration Risk, Percentage									21.20%	22.00%	24.00%
Government Contracts Concentration Risk [Member] | Sales Revenue, Net [Member]
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage									16.70%	17.60%	19.40%