Business Segments - Summary of company's operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Revenues from unaffiliated customers	$ 8,171	$ 6,990
Cost of goods sold, exclusive of depreciation and amortization	(6,476)	(5,438)
Selling, general and administrative	(1,765)	(1,576)
Interest expense	(21)	(9)
Arbitration award expense	(50)
Depreciation and amortization	(163)	(169)
Insurance proceeds - arbitration	4,500
Other income, net	2	1
Income (loss) before income tax provision (benefit)	4,198	(201)
Income tax provision (benefit)	1,427	(56)
Net income (loss)	2,771	(145)
Capital expenditures	281	418
Operating Segments
Segment Reporting Information [Line Items]
Revenues from unaffiliated customers	8,171	6,990
Cost of goods sold, exclusive of depreciation and amortization	(6,476)	(5,438)
Selling, general and administrative	(1,765)	(1,576)
Interest expense	(21)	(9)
Arbitration award expense	(50)
Depreciation and amortization	(163)	(169)
Insurance proceeds - arbitration	4,500
Other income, net	2	1
Income (loss) before income tax provision (benefit)	4,198	(201)
Income tax provision (benefit)	1,427	(56)
Net income (loss)	2,771	(145)
Capital expenditures	281	418
Operating Segments | ATG
Segment Reporting Information [Line Items]
Revenues from unaffiliated customers	6,353	5,305
Cost of goods sold, exclusive of depreciation and amortization	(4,751)	(3,840)
Selling, general and administrative	(1,359)	(1,140)
Interest expense	(13)	(9)
Arbitration award expense	(50)
Depreciation and amortization	(117)	(122)
Insurance proceeds - arbitration	4,500
Other income, net	2
Income (loss) before income tax provision (benefit)	4,565	194
Income tax provision (benefit)	1,552	54
Net income (loss)	3,013	140
Capital expenditures	188	372
Operating Segments | CPG
Segment Reporting Information [Line Items]
Revenues from unaffiliated customers	1,818	1,685
Cost of goods sold, exclusive of depreciation and amortization	(1,725)	(1,598)
Selling, general and administrative	(406)	(436)
Interest expense	(8)
Arbitration award expense
Depreciation and amortization	(46)	(47)
Insurance proceeds - arbitration
Other income, net		1
Income (loss) before income tax provision (benefit)	(367)	(395)
Income tax provision (benefit)	(125)	(110)
Net income (loss)	(242)	(285)
Capital expenditures	$ 93	$ 46