Income Taxes - Significant Components of the Company's Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred income tax assets
Compensation	$ 2,774	$ 3,030
Inventory valuation	695	502
Allowance for uncollectible accounts	237	268
Provision for loss on note receivable	5,031	0
Non-deductible accruals	4,196	2,195
Non-deductible intangibles	1,574	1,193
State deferred taxes	843	0
Capital loss carryforwards	1,982	1,982
Net operating loss carryforwards	0	405
Deferred tax assets, gross	17,332	9,575
Valuation allowance	(1,982)	(1,982)
Deferred Tax Assets, Net of Valuation Allowance	15,350	7,593
Deferred income tax liabilities
Property, plant and equipment	4,247	6,255
Tax-deductible goodwill	5,089	5,202
State deferred taxes	0	132
Other	744	149
Deferred tax liabilities, gross	10,080	11,738
Net deferred income tax (liability)		$ 4,145
Net deferred income tax asset	$ 5,270