General and Basis of Presentation - Revenue by Customer and Contract Type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Total	$ 52,559	$ 48,610	$ 108,317	$ 87,589
Firm fixed-price
Disaggregation of Revenue [Line Items]
Total	45,257	41,935	94,398	73,596
Time-and-materials
Disaggregation of Revenue [Line Items]
Total	3,059	3,637	6,089	7,462
Cost plus fixed fee
Disaggregation of Revenue [Line Items]
Total	4,243	3,038	7,830	6,531
Federal Government
Disaggregation of Revenue [Line Items]
Total	50,047	46,877	103,395	82,968
State & Local, and Commercial
Disaggregation of Revenue [Line Items]
Total	$ 2,512	$ 1,733	$ 4,922	$ 4,621