Contingencies - Additional Information (Detail) $ in Thousands, R$ in Millions	1 Months Ended		3 Months Ended
	Nov. 22, 2011 USD ($)	Nov. 22, 2011 BRL (R$)	Mar. 31, 2018 USD ($)	Mar. 31, 2018 BRL (R$)	Dec. 31, 2017 USD ($)	May 31, 2012 USD ($)
Loss Contingencies [Line Items]
Damages asserted by BK | R$				R$ 20.8
Business combination, recognized identifiable assets acquired and liabilities assumed, contingent liability						$ 2,900
Chassis converter pool Liability, Current			$ 13,883		$ 18,326
Supreme Industries Inc. [Member]
Loss Contingencies [Line Items]
Damages asserted by BK			40,000
Court-Imposed Interest, Fees or Inflation Adjustments
Loss Contingencies [Line Items]
Total ordered damages granted to Bk	$ 8,100
Court-Imposed Interest, Fees or Inflation Adjustments | Maximum
Loss Contingencies [Line Items]
Total ordered damages granted to Bk | R$		R$ 26.7
Chassis Converter Pool Agreements [Member]
Loss Contingencies [Line Items]
Other Inventory, Gross			$ 2,500