Related Party Transactions (Details 2)	12 Months Ended
	Dec. 31, 2012
Audi, Mercedes-Benz, Sprinter, Porsche, smart | Fairfield, Connecticut
Related party transactions
Ownership Interest (as a percent)	84.95%
Percentage of operating profit	20.00%
Ownership percentage, option to purchase	20.00%
Audi, Mercedes-Benz, Sprinter, Porsche, smart | Fairfield, Connecticut | Lucio A. Noto
Related party transactions
Ownership Interest (as a percent)	15.05%
Ferrari, Maserati | Las Vegas, Nevada
Related party transactions
Ownership Interest (as a percent)	50.00%
Lexus, Toyota | Frankfurt, Germany
Related party transactions
Ownership Interest (as a percent)	50.00%
Audi, Lexus, Skoda, Toyota, Volkswagen, Citroen | Aachen, Germany
Related party transactions
Ownership Interest (as a percent)	50.00%
BMW, MINI | Northern Italy
Related party transactions
Ownership Interest (as a percent)	70.00%