Accounts and Notes Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts and notes receivable
Total accounts and notes receivable	$ 176,260	$ 160,972
Less allowance for doubtful accounts	2,896	3,204
Accounts and notes receivable, net	173,364	157,768
Amounts due from manufacturers [Member]
Accounts and notes receivable
Total accounts and notes receivable	95,754	93,206
Parts and service receivables [Member]
Accounts and notes receivable
Total accounts and notes receivable	35,318	32,479
Finance and insurance receivables, net [Member]
Accounts and notes receivable
Total accounts and notes receivable	24,866	22,374
Other [Member]
Accounts and notes receivable
Total accounts and notes receivable	$ 20,322	$ 12,913