Note 7 - Commitments and Contingencies (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Lifetime Oil Contracts [Member]
Deferred Revenue	$ 80,200
Operating Leases, Rent Expense, Minimum Rentals	23,800	$ 17,200	$ 14,000
Charge Backs Liabilities	35,033
Contracts Obligations Reserve	3,400
Self Insurance Reserve	$ 25,900	$ 23,200