Segment Information - Financial Data by Segment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Net sales	$ 182,087,559	$ 164,003,040
Operating income	12,769,987	11,412,664
Assets	144,438,684	129,867,736
Additions to property, plant and equipment	6,373,000	2,569,000
Depreciation and amortization	4,049,000	3,841,000
United States Segment
Net sales	152,475,000	140,191,000
Operating income	9,521,000	8,872,000
Assets	125,521,000	113,831,000
Additions to property, plant and equipment	6,309,000	2,386,000
Depreciation and amortization	3,822,000	3,668,000
Canada Segment
Net sales	14,341,000	10,986,000
Operating income	1,893,000	1,332,000
Assets	9,100,000	7,432,000
Additions to property, plant and equipment	10,000	34,000
Depreciation and amortization	147,000	95,000
Europe Segment
Net sales	15,272,000	12,826,000
Operating income	1,356,000	1,209,000
Assets	9,818,000	8,605,000
Additions to property, plant and equipment	54,000	149,000
Depreciation and amortization	$ 80,000	$ 78,000