Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.3
Business and Credit Concentrations - Company's Top Five Manufacturers Produced (Detail) - Cost of Goods, Total [Member] - Supplier Concentration Risk [Member]
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Concentration Risk [Line Items]        
Percentage of total production 42.20% 40.30% 41.10% 41.90%
Manufacturer One [Member]        
Concentration Risk [Line Items]        
Percentage of total production 16.50% 11.10% 15.80% 11.30%
Manufacturer Two [Member]        
Concentration Risk [Line Items]        
Percentage of total production 8.30% 10.10% 8.30% 10.70%
Manufacturer Three [Member]        
Concentration Risk [Line Items]        
Percentage of total production 7.20% 6.80% 6.90% 9.10%
Manufacturer Four [Member]        
Concentration Risk [Line Items]        
Percentage of total production 5.50% 6.70% 5.10% 5.40%
Manufacturer Five [Member]        
Concentration Risk [Line Items]        
Percentage of total production 4.70% 5.60% 5.00% 5.40%