Accounts and Notes Receivable (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Accounts and notes receivable
Total accounts and notes receivable	$ 137,343	$ 112,873
Less allowance for doubtful accounts	2,285	1,645
Accounts and notes receivable, net	135,058	111,228
Amounts due from manufacturers [Member]
Accounts and notes receivable
Total accounts and notes receivable	78,131	64,039
Parts and service receivables [Member]
Accounts and notes receivable
Total accounts and notes receivable	31,950	17,879
Finance and insurance receivables, net [Member]
Accounts and notes receivable
Total accounts and notes receivable	19,283	16,060
Other [Member]
Accounts and notes receivable
Total accounts and notes receivable	$ 7,979	$ 14,895