Note 9 - Income Taxes (Details) - Deferred Tax Assets and Liabilities (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Insurance and claims	$ 11,691	$ 11,950
Net operating loss carryovers	13,681	16,978
Other	6,035	6,269
Valuation allowance	(983)	(299)
Total deferred tax assets	30,424	34,898
Deferred tax liabilities:
Property and equipment	(76,280)	(76,748)
Other	(4,793)	(291)
Prepaid expenses	(3,194)	(3,054)
Total net deferred tax liabilities	(84,267)	(80,093)
Net deferred tax liability	$ (53,843)	$ (45,195)