Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013 Segment	Dec. 31, 2012	Dec. 31, 2011
Segment Information [Abstract]
Percentage of revenues derived from customers in the nuclear power industry									65.00%	59.00%	67.00%
Number of reportable business segments									1
Contract range, minimum									10 months
Contract range, maximum									3 years
Segment Reporting Information [Line Items]
Contract revenue	$ 12,262	$ 11,883	$ 11,034	$ 12,383	$ 12,665	$ 13,009	$ 13,183	$ 13,389	$ 47,562	$ 52,246	$ 51,126
Transfers between geographic locations									0	0	0
Total contract revenue									47,562	52,246	51,126
Operating income (loss)	(492)	(922)	(7,965)	(1,289)	(137)	1,356	560	218	(10,668)	1,997	2,228
Assets	48,827				62,564				48,827	62,564	58,815
Percentage of revenues derived from international sales									67.00%	70.00%	66.00%
United States [Member]
Segment Reporting Information [Line Items]
Contract revenue									33,419	36,222	37,587
Transfers between geographic locations									5,602	2,226	1,379
Total contract revenue									39,021	38,448	38,966
Operating income (loss)									(7,767)	585	745
Assets	67,255				81,792				67,255	81,792	78,900
Europe [Member]
Segment Reporting Information [Line Items]
Contract revenue									8,639	15,005	12,443
Transfers between geographic locations									446	494	0
Total contract revenue									9,085	15,499	12,443
Operating income (loss)									(3,053)	1,285	1,293
Assets	11,206				15,543				11,206	15,543	13,429
Asia [Member]
Segment Reporting Information [Line Items]
Contract revenue									5,504	1,019	1,096
Transfers between geographic locations									636	661	416
Total contract revenue									6,140	1,680	1,512
Operating income (loss)									152	127	190
Assets	6,508				1,640				6,508	1,640	1,002
Eliminations [Member]
Segment Reporting Information [Line Items]
Contract revenue									0	0	0
Transfers between geographic locations									(6,684)	(3,381)	(1,795)
Total contract revenue									(6,684)	(3,381)	(1,795)
Operating income (loss)									0	0	0
Assets	$ (36,142)				$ (36,411)				$ (36,142)	$ (36,411)	$ (34,516)