Segment Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 370,785,000	$ 349,637,000
Interest Expense	603,000	1,009,000
Gross Profit	197,354,000	189,540,000
Operating Income (Loss)	9,066,000	9,210,000
Long-Lived Assets	61,327,000	57,046,000
Other Nonoperating Income (Expense)	1,211,000	(1,338,000)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	9,674,000	6,863,000
Payments to Acquire Property, Plant, and Equipment	2,028,000	2,524,000
Depreciation, Depletion and Amortization	5,893,000	6,855,000
Assets	204,429,000	197,142,000
Notes Receivable, Related Parties	(8,548,000)	(8,141,000)
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	295,675,000	279,917,000
Long-Lived Assets	25,478,000	25,539,000
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	75,110,000	69,720,000
Long-Lived Assets	35,849,000	31,507,000
Lawson [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	329,367,000	313,095,000
Gross Profit	181,567,000	175,517,000
Operating Income (Loss)	6,483,000	7,500,000
Payments to Acquire Property, Plant, and Equipment	1,522,000	1,907,000
Depreciation, Depletion and Amortization	4,757,000	6,008,000
Assets	168,803,000	169,216,000
Bolt [Member] [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	41,418,000	36,542,000
Gross Profit	15,787,000	14,023,000
Operating Income (Loss)	2,583,000	1,710,000
Payments to Acquire Property, Plant, and Equipment	506,000	617,000
Depreciation, Depletion and Amortization	1,136,000	847,000
Assets	$ 44,174,000	$ 36,067,000