Note 12 - Subsequent Event (Details Textual) - USD ($)	Jul. 07, 2016	Jun. 30, 2016	Dec. 31, 2015
Subsequent Event [Member] | BMO Harris Bank N.A. [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	1.51%
Subsequent Event [Member] | BMO Harris Bank N.A. [Member] | If Termination Occurs on or Before January 1, 2018 [Member]
Debt Instrument, Prepayment Processing Fee, Percent	2.00%
Subsequent Event [Member] | BMO Harris Bank N.A. [Member] | If Termination Occurs after January 1, 2018 and on or Prior to July 1, 2018 [Member]
Debt Instrument, Prepayment Processing Fee, Percent	1.00%
Subsequent Event [Member] | BMO Harris Bank N.A. [Member] | IfTermination Occurs after July 1, 2018 and Prior to June 30, 2019 [Member]
Debt Instrument, Prepayment Processing Fee Amount	$ 500,000
Subsequent Event [Member] | BMO Harris Bank N.A. [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 875,000,000
Debt Instrument, Working Capital Fee Percentage	0.16%
Purchase of Used Inventory, Maximum	$ 150,000,000
Floor Plan Notes Payable	$ 658,000,000
Floor Plan Notes Payable		$ 830,092,000	$ 854,758,000