Segment Information, Loss before income taxes (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues	$ 92,249	$ 92,249	$ 70,880	[1]
Depreciation		515	342
Amortization of definite-lived intangible assets		1,612	335
Operating income		1,366	229
Interest (expense) income, net		(268)	80
(Loss) Gain on derivative instruments, net		(350)	99
Other income (expense), net		29	(4)
Income before income taxes		777	404
Performance Improvement Solutions [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues		42,954	39,899
Depreciation		385	321
Amortization of definite-lived intangible assets		898	246
Operating income		2,640	(3,191)
Nuclear Industry Training and Consulting [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues		49,295	30,981
Depreciation		130	21
Amortization of definite-lived intangible assets		714	89
Operating income		$ (1,274)	$ 3,420

[1] Prior period amounts have not been adjusted under the modified retrospective transition method for the adoption of ASC 606.