Income Taxes - Deferred Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Allowance for doubtful accounts	$ 382	$ 212
Inventory reserves	1,388	1,353
Warranty liability	1,643	1,559
Deferred compensation	1,380	1,264
Earnout liabilities	406	516
Pension and retiree health benefit obligations	1,682	1,219
Interest rate swap	1,733
Accrued vacation	833	702
Medical claims reserve	56	78
Operating lease liabilities	6,108
Net operating losses	3,754	4,416
Other accrued liabilities	2,953	2,176
Valuation allowance	(1,612)	(1,473)
Total deferred tax assets	20,706	12,022
Deferred tax liabilities:
Tax deductible goodwill and other intangibles	(54,808)	(53,565)
Accelerated depreciation	(7,320)	(6,547)
Operating leases - right of use assets	(6,108)
Other	319	(108)
Total deferred tax liabilities	(67,917)	(60,220)
Net deferred tax liabilities	(47,211)	(48,198)
Valuation allowance for state net operating losses	1,612	$ 1,473
State
Deferred tax liabilities:
Operating loss carry forwards	$ 2,919