DETAIL OF CERTAIN BALANCE SHEET ACCOUNTS - Summary of Inventories (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Schedule Of Inventory Current [Line Items]
Inventories, net	$ 1,107,193	$ 867,470
New vehicles [Member]
Schedule Of Inventory Current [Line Items]
Inventories, net	814,715	610,694
Used vehicles [Member]
Schedule Of Inventory Current [Line Items]
Inventories, net	175,260	153,648
Rental vehicles [Member]
Schedule Of Inventory Current [Line Items]
Inventories, net	67,563	57,790
Parts, accessories and other [Member]
Schedule Of Inventory Current [Line Items]
Inventories, net	$ 49,655	$ 45,338