Description of Business and Summary of Significant Accounting Policies (Organization and Business, Inventory) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 brand franchises stores	Dec. 31, 2012
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Owned and operated new vehicle franchises	269
Number of stores	228
Number of brands	33
Percentage of new vehicle sales core brand vehicles	95.00%
Floorplan interest assistance, inventory cost reduction	$ 19.7	$ 15.8