Note 7 - Commitments and Contingencies (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Leases, Rent Expense, Minimum Rentals	$ 26,800	$ 23,800	$ 17,200
Charge Backs Liabilities	44,228
Contracts Obligations Reserve	3,400
Self Insurance Reserve	32,800	$ 25,900
Lifetime Oil Contracts [Member]
Deferred Revenue	$ 99,600