Quarterly report pursuant to Section 13 or 15(d)

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

v3.20.2
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, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Concentration Risk [Line Items]        
Percentage of total production 39.60% 42.20% 42.20% 41.10%
Manufacturer One [Member]        
Concentration Risk [Line Items]        
Percentage of total production 16.40% 16.50% 20.60% 15.80%
Manufacturer Two [Member]        
Concentration Risk [Line Items]        
Percentage of total production 6.70% 8.30% 6.90% 8.30%
Manufacturer Three [Member]        
Concentration Risk [Line Items]        
Percentage of total production 6.00% 7.20% 5.80% 6.90%
Manufacturer Four [Member]        
Concentration Risk [Line Items]        
Percentage of total production 5.70% 5.50% 4.50% 5.10%
Manufacturer Five [Member]        
Concentration Risk [Line Items]        
Percentage of total production 4.80% 4.70% 4.40% 5.00%