Quarterly report pursuant to Section 13 or 15(d)

Business and Credit Concentrations - Company's Top Five Manufacturers Produced (Detail)

v3.8.0.1
Business and Credit Concentrations - Company's Top Five Manufacturers Produced (Detail) - Cost of Goods, Total [Member] - Supplier Concentration Risk [Member]
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Concentration Risk [Line Items]    
Percentage of total production 48.30% 53.30%
Manufacturer One [Member]    
Concentration Risk [Line Items]    
Percentage of total production 15.50% 22.80%
Manufacturer Two [Member]    
Concentration Risk [Line Items]    
Percentage of total production 11.90% 10.90%
Manufacturer Three [Member]    
Concentration Risk [Line Items]    
Percentage of total production 8.60% 9.40%
Manufacturer Four [Member]    
Concentration Risk [Line Items]    
Percentage of total production 6.90% 5.60%
Manufacturer Five [Member]    
Concentration Risk [Line Items]    
Percentage of total production 5.40% 4.60%