Quarterly report pursuant to Section 13 or 15(d)

Inventories - Components of Inventories (Detail)

v2.4.1.9
Inventories - Components of Inventories (Detail) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Inventory Disclosure [Abstract]    
New vehicles $ 856,967sah_InventoryNewVehicles $ 924,818sah_InventoryNewVehicles
Used vehicles 246,713sah_InventoryUsedVehicles 214,015sah_InventoryUsedVehicles
Service loaners 115,741sah_InventoryServiceLoaners 112,520sah_InventoryServiceLoaners
Parts, accessories and other 60,606us-gaap_OtherInventoriesSpareParts 60,349us-gaap_OtherInventoriesSpareParts
Net inventories $ 1,280,027us-gaap_InventoryNet $ 1,311,702us-gaap_InventoryNet