Annual report pursuant to Section 13 and 15(d)

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

v3.3.1.900
Business and Credit Concentrations - Company's Top Five Manufacturers Produced (Detail) - Cost of Goods, Total [Member] - Supplier Concentration Risk [Member]
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Concentration Risk [Line Items]      
Percentage of total production 56.50% 58.90% 59.90%
Manufacturer One [Member]      
Concentration Risk [Line Items]      
Percentage of total production 31.50% 37.50% 37.80%
Manufacturer Two [Member]      
Concentration Risk [Line Items]      
Percentage of total production 9.10% 6.10% 7.10%
Manufacturer Three [Member]      
Concentration Risk [Line Items]      
Percentage of total production 7.30% 5.70% 6.10%
Manufacturer Four [Member]      
Concentration Risk [Line Items]      
Percentage of total production 5.00% 4.90% 4.80%
Manufacturer Five [Member]      
Concentration Risk [Line Items]      
Percentage of total production 3.60% 4.70% 4.10%