6. Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Net Sales:
Customer sales	$ 10,731	$ 9,850	$ 21,427	$ 19,422
Intercompany sales	0	0	0	0
Total Net Sales	10,731	9,850	21,427	19,422
Net income	352	87	220	331
Segment assets	37,706	37,705	37,706	37,705	$ 35,729
Inter-Company Eliminations [Member]
Net Sales:
Customer sales	0	0	0	0
Intercompany sales	(2,609)	(2,670)	(4,852)	(5,656)
Total Net Sales	(2,609)	(2,670)	(4,852)	(5,656)
Net income	27	79	(41)	(4)
Segment assets	(477)	(444)	(477)	(444)
United States (Corpus Christi) [Member]
Net Sales:
Customer sales	7,074	6,878	14,069	13,369
Intercompany sales	21	0	37	53
Total Net Sales	7,095	6,878	14,106	13,422
Net income	(3)	(245)	(74)	(278)
Segment assets	17,556	17,180	17,556	17,180
European (TPT) [Member]
Net Sales:
Customer sales	2,685	2,270	5,479	4,705
Intercompany sales	1,534	1,925	2,810	3,285
Total Net Sales	4,219	4,195	8,289	7,990
Net income	192	247	115	567
Segment assets	15,183	14,013	15,183	14,013
Asian (TMM) [Member]
Net Sales:
Customer sales	972	702	1,879	1,348
Intercompany sales	1,054	745	2,005	2,318
Total Net Sales	2,026	1,447	3,884	3,666
Net income	136	6	220	46
Segment assets	$ 5,444	$ 6,956	$ 5,444	$ 6,956