Income Taxes - Significant Components of the Company's Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred income tax assets
Compensation	$ 2,268	$ 2,774
Inventory valuation	873	695
Allowance for uncollectible accounts	290	237
Provision for loss on note receivable	5,031	5,031
Non-deductible accruals	5,370	4,196
Operating lease liability	1,288	0
Non-deductible intangibles	1,862	1,574
State deferred taxes	730	843
Capital loss carryforwards	1,982	1,982
Deferred tax assets, gross	19,694	17,332
Valuation allowance	(1,982)	(1,982)
Deferred Tax Assets, Net of Valuation Allowance	17,712	15,350
Deferred income tax liabilities
Property, plant and equipment	4,867	4,247
Tax-deductible goodwill	4,862	5,089
Right of use asset - operating leases	1,239	0
Other	937	744
Deferred tax liabilities, gross	11,905	10,080
Net deferred income tax asset	$ 5,807	$ 5,270