Revenue from Contracts with Clients - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 88,652	$ 95,670	$ 276,409	$ 292,610
Percent of Total Revenue	100.00%	100.00%	100.00%	100.00%
United States
Disaggregation of Revenue [Line Items]
Revenue	$ 47,721	$ 49,936	$ 143,526	$ 149,374
Percent of Total Revenue	53.90%	52.30%	52.00%	51.10%
Latin America
Disaggregation of Revenue [Line Items]
Revenue	$ 474	$ 1,669	$ 2,304	$ 6,014
Percent of Total Revenue	0.50%	1.70%	0.80%	2.10%
Europe
Disaggregation of Revenue [Line Items]
Revenue	$ 11,465	$ 10,556	$ 37,434	$ 32,512
Percent of Total Revenue	12.90%	11.00%	13.50%	11.10%
Middle East
Disaggregation of Revenue [Line Items]
Revenue	$ 21,024	$ 25,447	$ 67,125	$ 79,730
Percent of Total Revenue	23.70%	26.60%	24.30%	27.20%
Africa
Disaggregation of Revenue [Line Items]
Revenue	$ 6,263	$ 7,005	$ 20,818	$ 20,884
Percent of Total Revenue	7.10%	7.30%	7.50%	7.10%
Asia/Pacific
Disaggregation of Revenue [Line Items]
Revenue	$ 1,705	$ 1,057	$ 5,202	$ 4,096
Percent of Total Revenue	1.90%	1.10%	1.90%	1.40%
Fixed Price
Disaggregation of Revenue [Line Items]
Revenue	$ 20,013	$ 19,836	$ 57,984	$ 64,421
Fixed Price | United States
Disaggregation of Revenue [Line Items]
Revenue	4,574	4,043	13,797	11,156
Fixed Price | Latin America
Disaggregation of Revenue [Line Items]
Revenue	472	1,662	1,939	5,651
Fixed Price | Europe
Disaggregation of Revenue [Line Items]
Revenue	7,387	5,741	25,566	17,094
Fixed Price | Middle East
Disaggregation of Revenue [Line Items]
Revenue	7,655	7,567	16,481	27,797
Fixed Price | Africa
Disaggregation of Revenue [Line Items]
Revenue	(75)	388	201	1,559
Fixed Price | Asia/Pacific
Disaggregation of Revenue [Line Items]
Revenue	0	435	0	1,164
T&M
Disaggregation of Revenue [Line Items]
Revenue	68,639	75,834	218,425	228,189
T&M | United States
Disaggregation of Revenue [Line Items]
Revenue	43,147	45,893	129,729	138,218
T&M | Latin America
Disaggregation of Revenue [Line Items]
Revenue	2	7	365	363
T&M | Europe
Disaggregation of Revenue [Line Items]
Revenue	4,078	4,815	11,868	15,418
T&M | Middle East
Disaggregation of Revenue [Line Items]
Revenue	13,369	17,880	50,644	51,933
T&M | Africa
Disaggregation of Revenue [Line Items]
Revenue	6,338	6,617	20,617	19,325
T&M | Asia/Pacific
Disaggregation of Revenue [Line Items]
Revenue	$ 1,705	$ 622	$ 5,202	$ 2,932