Income Taxes - Deferred Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Allowance for doubtful accounts	$ 393	$ 492
Inventory reserves	1,111	928
Warranty liability	2,244	2,717
Deferred compensation	548	733
Earnout liabilities	242	1,367
Pension and retiree health benefit obligations	5,432	3,375
Accrued vacation	866	720
Medical claims reserve	72	75
State net operating losses	2,853	3,164
Other accrued liabilities	2,967	3,229
Valuation allowance for state net operating losses	(640)	(647)
Total deferred tax assets	16,088	16,153
Deferred tax liabilities:
Tax deductible goodwill and other intangibles	(63,324)	(57,496)
Accelerated depreciation	(7,176)	(7,239)
Other	(151)	(196)
Total deferred tax liabilities	(70,651)	(64,931)
Net deferred tax liabilities	(54,563)	(48,778)
State net operating losses	2,853	3,164
Valuation allowance for state net operating losses	640	$ 647
State
Deferred tax liabilities:
Operating loss carry forwards	$ 2,853