Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Information [Abstract]
Percentage of revenues derived from customers in the nuclear power industry									59.00%	67.00%	72.00%
Segment Reporting Information [Line Items]
Contract revenue	$ 12,665	$ 13,009	$ 13,183	$ 13,389	$ 14,998	$ 12,549	$ 11,257	$ 12,322	$ 52,246	$ 51,126	$ 47,213
Transfers between geographic locations									0	0	0
Total contract revenue									52,246	51,126	47,213
Operating Income Loss	(137)	1,356	560	218	1,292	975	248	(287)	1,997	2,228	(1,232)
Assets	62,564				58,815				62,564	58,815	53,614
Percentage of revenues derived from international sales									70.00%	66.00%	71.00%
United States [Member]
Segment Reporting Information [Line Items]
Contract revenue									36,222	37,587	37,197
Transfers between geographic locations									2,226	1,379	352
Total contract revenue									38,448	38,966	37,549
Operating Income Loss									585	745	(2,397)
Assets	81,792				78,900				81,792	78,900	70,783
Europe [Member]
Segment Reporting Information [Line Items]
Contract revenue									15,005	12,443	9,699
Transfers between geographic locations									494	0	0
Total contract revenue									15,499	12,443	9,699
Operating Income Loss									1,285	1,293	1,157
Assets	15,543				13,429				15,543	13,429	12,689
Asia [Member]
Segment Reporting Information [Line Items]
Contract revenue									1,019	1,096	317
Transfers between geographic locations									661	416	798
Total contract revenue									1,680	1,512	1,115
Operating Income Loss									127	190	8
Assets	1,640				1,002				1,640	1,002	353
Eliminations [Member]
Segment Reporting Information [Line Items]
Contract revenue									0	0	0
Transfers between geographic locations									(3,381)	(1,795)	(1,150)
Total contract revenue									(3,381)	(1,795)	(1,150)
Operating Income Loss									0	0	0
Assets	$ (36,411)				$ (34,516)				$ (36,411)	$ (34,516)	$ (30,211)