CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CONSOLIDATED STATEMENTS OF CASH FLOWS
Dealership acquisitions net, repayment of sellers' floor plan notes payable	$ 74,867	$ 54,453	$ 9,883
5.75% Notes
Statement
Interest rate (as a percent)	5.75%
7.75% Notes
Statement
Interest rate (as a percent)		7.75%
3.5% Notes
Statement
Interest rate (as a percent)		3.50%	3.50%