Note 8 - Leases (Details) - Summary of Rental Expense (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Note 8 - Leases (Details) - Summary of Rental Expense [Line Items]
Rental expense	$ 27,397	$ 24,139	$ 19,442
Revenue Equipment [Member]
Note 8 - Leases (Details) - Summary of Rental Expense [Line Items]
Rental expense	22,991	19,746	15,364
Land and Building [Member]
Note 8 - Leases (Details) - Summary of Rental Expense [Line Items]
Rental expense	4,044	3,714	3,266
Other Machinery and Equipment [Member]
Note 8 - Leases (Details) - Summary of Rental Expense [Line Items]
Rental expense	$ 362	$ 679	$ 812