Revenue (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($) Obligation	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) Stream Obligation	Jun. 30, 2018 USD ($)
Disaggregation of Revenue [Abstract]
Revenue	$ 23,458	$ 24,698	$ 45,652	$ 47,593
Number of broad revenue streams | Stream			3
Contract with Customer, Asset and Liability [Abstract]
Revenue recognized in the period from amounts included in Billings in Excess at the beginning of the period	2,813	2,738	$ 7,853	7,954
Amount of revenue recognized related to performance obligations satisfied in previous periods	$ 1,103		$ 1,850
Revenue, Performance Obligation [Abstract]
Number of performance obligations | Obligation	2		2
Remaining performance obligation	$ 27,159		$ 27,159
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01
Revenue, Performance Obligation [Abstract]
Expected period to recognize revenue as performance obligations are satisfied	12 months		12 months
Performance Improvement Solutions [Member]
Disaggregation of Revenue [Abstract]
Revenue	$ 13,010	10,864	$ 25,200	20,765
Performance Improvement Solutions [Member] | System Design and Build [Member]
Disaggregation of Revenue [Abstract]
Revenue	5,595	7,300	12,037	14,795
Performance Improvement Solutions [Member] | Software [Member]
Disaggregation of Revenue [Abstract]
Revenue	635	546	1,384	1,415
Performance Improvement Solutions [Member] | Training and Consulting Services [Member]
Disaggregation of Revenue [Abstract]
Revenue	6,780	3,018	11,779	4,555
Nuclear Industry Training and Consulting [Member]
Disaggregation of Revenue [Abstract]
Revenue	10,448	13,834	20,452	26,828
Nuclear Industry Training and Consulting [Member] | Training and Consulting Services [Member]
Disaggregation of Revenue [Abstract]
Revenue	$ 10,448	$ 13,834	$ 20,452	$ 26,828