Note 4 - Prepaid Expenses and Other Current Assets (Details) - Prepaid Expenses and Other Current Assets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Note 4 - Prepaid Expenses and Other Current Assets (Details) - Prepaid Expenses and Other Current Assets [Line Items]
Prepaid expenses and other current assets	$ 16,064	$ 15,415
Prepaid Tires [Member]
Note 4 - Prepaid Expenses and Other Current Assets (Details) - Prepaid Expenses and Other Current Assets [Line Items]
Prepaid expenses and other current assets	10,607	9,174
Prepaid Licenses, Permits and Tolls [Member]
Note 4 - Prepaid Expenses and Other Current Assets (Details) - Prepaid Expenses and Other Current Assets [Line Items]
Prepaid expenses and other current assets	1,915	1,951
Prepaid Insurance [Member]
Note 4 - Prepaid Expenses and Other Current Assets (Details) - Prepaid Expenses and Other Current Assets [Line Items]
Prepaid expenses and other current assets	1,414	1,649
Other Current Assets [Member]
Note 4 - Prepaid Expenses and Other Current Assets (Details) - Prepaid Expenses and Other Current Assets [Line Items]
Prepaid expenses and other current assets	$ 2,128	$ 2,641