Detail of Certain Balance Sheet Accounts (Inventories) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Summary of inventories
Lower of cost or market reserves	$ 7,371	$ 7,656
Inventories, net	1,537,112	1,542,318
Inventory, Gross	1,544,483	1,549,974
New vehicles [Member]
Summary of inventories
Inventory, Gross	1,151,182	1,165,335
Used vehicles [Member]
Summary of inventories
Inventory, Gross	239,177	231,960
Rental vehicles [Member]
Summary of inventories
Inventory, Gross	89,041	88,523
Parts, accessories and other [Member]
Summary of inventories
Inventory, Gross	$ 65,083	$ 64,156