Business Segments - Summary of company's operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Revenues from unaffiliated customers	$ 40,558	$ 49,844
Costs of goods sold, inclusive of depreciation	(34,570)	(41,604)
Gross margin	5,988	8,240
Operating expenses:
Selling, general and administrative	(9,423)	(7,998)
Legal settlement awards	(1,890)
Total operating expenses	(11,313)	(7,998)
Operating (loss)/income	(5,325)	242
Other income/(expense):
Other income: employee retention credit (ERC)	5,622
Other income: PPP loan forgiveness	4,000
Interest expense, net	(187)	(180)
Loss on sale of equipment	(98)
Total other income/(expense)	9,337	(180)
Income (loss) before income tax provision	4,012	62
Income tax benefit	(43)	(38)
Net income/(loss)	4,055	100
Capital expenditures	267	729
Operating Segments
Segment Reporting Information [Line Items]
Revenues from unaffiliated customers	40,558	49,844
Costs of goods sold, inclusive of depreciation	(34,570)	(41,604)
Gross margin	$ 5,988	$ 8,240
Gross margin %	14.80%	16.50%
Operating expenses:
Selling, general and administrative	$ (9,423)	$ (7,998)
Legal settlement awards	(1,890)
Total operating expenses	(11,313)	(7,998)
Operating (loss)/income	(5,325)	242
Other income/(expense):
Other income: employee retention credit (ERC)	5,622
Other income: PPP loan forgiveness	4,000
Interest expense, net	(187)	(180)
Loss on sale of equipment	(98)
Total other income/(expense)	9,337	(180)
Income (loss) before income tax provision	4,012	62
Income tax benefit	(43)	(38)
Net income/(loss)	4,055	100
Operating Segments | ATG
Segment Reporting Information [Line Items]
Revenues from unaffiliated customers	31,677	40,782
Costs of goods sold, inclusive of depreciation	(25,929)	(33,440)
Gross margin	$ 5,748	$ 7,342
Gross margin %	18.10%	18.00%
Operating expenses:
Selling, general and administrative	$ (7,661)	$ (6,245)
Legal settlement awards	(1,800)
Total operating expenses	(9,461)	(6,245)
Operating (loss)/income	(3,713)	1,097
Other income/(expense):
Other income: employee retention credit (ERC)	4,584
Other income: PPP loan forgiveness	4,000
Interest expense, net	(185)	(170)
Loss on sale of equipment	(98)
Total other income/(expense)	8,301	(170)
Income (loss) before income tax provision	4,588	927
Income tax benefit	78	492
Net income/(loss)	4,510	435
Operating Segments | CPG
Segment Reporting Information [Line Items]
Revenues from unaffiliated customers	8,881	9,062
Costs of goods sold, inclusive of depreciation	(8,641)	(8,164)
Gross margin	$ 240	$ 898
Gross margin %	2.70%	9.90%
Operating expenses:
Selling, general and administrative	$ (1,762)	$ (1,753)
Legal settlement awards	(90)
Total operating expenses	(1,852)	(1,753)
Operating (loss)/income	(1,612)	(855)
Other income/(expense):
Other income: employee retention credit (ERC)	1,038
Interest expense, net	(2)	(10)
Total other income/(expense)	1,036	(10)
Income (loss) before income tax provision	(576)	(865)
Income tax benefit	(121)	(530)
Net income/(loss)	$ (455)	$ (335)