Business Segments - Summary of company's operations (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Revenues from unaffiliated customers	$ 11,230		$ 10,028		$ 22,398	$ 19,088
Costs of goods sold, inclusive of depreciation and amortization	(10,062)		(8,156)		(18,592)	(16,223)
Gross margin	1,168		1,872		3,806	2,865
Operating Expenses:
Selling, general and administrative	(2,071)		(2,209)		(4,253)	(4,182)
Operating loss	(903)		(337)		(447)	(1,317)
Other income/(expense):
Other income: employee retention credit (ERC)			1,914			3,644
Interest expense	(74)		(66)		(144)	(127)
Gain on sale of equipment					26
Total other (expense)/income, net	(74)		1,848		(118)	3,517
(Loss) income before income taxes	(977)		1,511		(565)	2,200
Income tax (benefit)/provision	(167)		325		(80)	473
Net (loss)/income	(810)	$ 325	1,186	$ 541	(485)	1,727
Operating Segments
Segment Reporting Information [Line Items]
Revenues from unaffiliated customers	11,230		10,028		22,398	19,088
Costs of goods sold, inclusive of depreciation and amortization	(10,062)		(8,156)		(18,592)	(16,223)
Gross margin	$ 1,168		$ 1,872		$ 3,806	$ 2,865
Gross margin %	10.40%		18.70%		17.00%	15.00%
Operating Expenses:
Selling, general and administrative	$ (2,071)		$ (2,209)		$ (4,253)	$ (4,182)
Total operating costs and expenses	(12,133)		(10,365)		(22,845)	(20,405)
Operating loss	(903)		(337)		(447)	(1,317)
Other income/(expense):
Other income: employee retention credit (ERC)			1,914			3,644
Interest expense	(74)		(66)		(144)	(127)
Gain on sale of equipment					26
Total other (expense)/income, net	(74)		1,848		(118)	3,517
(Loss) income before income taxes	(977)		1,511		(565)	2,200
Income tax (benefit)/provision	(167)		325		(80)	473
Net (loss)/income	(810)		1,186		(485)	1,727
Capital expenditures	313		(1)		390	13
Operating Segments | ATG
Segment Reporting Information [Line Items]
Revenues from unaffiliated customers	8,748		7,823		17,916	15,046
Costs of goods sold, inclusive of depreciation and amortization	(8,055)		(6,242)		(14,870)	(12,452)
Gross margin	$ 693		$ 1,581		$ 3,046	$ 2,594
Gross margin %	7.90%		20.20%		17.00%	17.20%
Operating Expenses:
Selling, general and administrative	$ (1,575)		$ (1,761)		$ (3,349)	$ (3,346)
Total operating costs and expenses	(9,630)		(8,003)		(18,219)	(15,798)
Operating loss	(882)		(180)		(303)	(752)
Other income/(expense):
Other income: employee retention credit (ERC)			1,573			2,986
Interest expense	(74)		(65)		(144)	(125)
Gain on sale of equipment					26
Total other (expense)/income, net	(74)		1,508		(118)	2,861
(Loss) income before income taxes	(956)		1,328		(421)	2,109
Income tax (benefit)/provision	(173)		285		(60)	453
Net (loss)/income	(783)		1,043		(361)	1,656
Capital expenditures	313				390	10
Operating Segments | CPG
Segment Reporting Information [Line Items]
Revenues from unaffiliated customers	2,482		2,205		4,482	4,042
Costs of goods sold, inclusive of depreciation and amortization	(2,007)		(1,914)		(3,722)	(3,771)
Gross margin	$ 475		$ 291		$ 760	$ 271
Gross margin %	19.10%		13.20%		17.00%	6.70%
Operating Expenses:
Selling, general and administrative	$ (496)		$ (448)		$ (904)	$ (836)
Total operating costs and expenses	(2,503)		(2,362)		(4,626)	(4,607)
Operating loss	(21)		(157)		(144)	(565)
Other income/(expense):
Other income: employee retention credit (ERC)			341			658
Interest expense			(1)			(2)
Total other (expense)/income, net			340			656
(Loss) income before income taxes	(21)		183		(144)	91
Income tax (benefit)/provision	6		40		(20)	20
Net (loss)/income	$ (27)		143		$ (124)	71
Capital expenditures			$ (1)			$ 3