Accounts and Notes Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accounts and notes receivable
Total accounts and notes receivable	$ 160,972	$ 154,971
Less allowance for doubtful accounts	3,204	3,641
Accounts and notes receivable, net	157,768	151,330
Amounts due from manufacturers [Member]
Accounts and notes receivable
Total accounts and notes receivable	93,206	86,062
Parts and service receivables [Member]
Accounts and notes receivable
Total accounts and notes receivable	32,479	35,034
Finance and insurance receivables, net [Member]
Accounts and notes receivable
Total accounts and notes receivable	22,374	20,898
Other [Member]
Accounts and notes receivable
Total accounts and notes receivable	$ 12,913	$ 12,977