Note 2 - Summary of Significant Accounting Policies (Detail) (USD $)			12 Months Ended						12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Top 10 Customers [Member] Accounts Receivable [Member]	Dec. 31, 2011 Top 10 Customers [Member] Accounts Receivable [Member]	Dec. 31, 2012 Top 10 Customers [Member]	Dec. 31, 2011 Top 10 Customers [Member]	Dec. 31, 2010 Top 10 Customers [Member]	Dec. 31, 2012 Personal Injury And Property Damage [Member]	Dec. 31, 2013 Workers Compensation [Member]	Dec. 31, 2012 Tractors [Member] Minimum [Member]	Dec. 31, 2012 Tractors [Member] Maximum [Member]	Dec. 31, 2012 Trailing Equipment [Member] Minimum [Member]	Dec. 31, 2012 Trailing Equipment [Member] Maximum [Member]	Dec. 31, 2012 Land, Buildings and Improvements [Member] Minimum [Member]	Dec. 31, 2012 Land, Buildings and Improvements [Member] Maximum [Member]	Dec. 31, 2012 Furniture and Fixtures [Member] Minimum [Member]	Dec. 31, 2012 Furniture and Fixtures [Member] Maximum [Member]	Dec. 31, 2012 Minimum [Member]	Dec. 31, 2012 Maximum [Member]
Allowance for Doubtful Accounts Receivable (in Dollars)	$ 6,600,000	$ 6,700,000
Property, Plant and Equipment, Useful Life										4 years	10 years	7 years	20 years	10 years	40 years	3 years	10 years
Property, Plant and Equipment, Salvage Value, Percentage																		10.00%	30.00%
Entity-Wide Revenue, Major Customer, Percentage					30.00%	32.00%	34.00%
Concentration Risk, Percentage			26.00%	27.00%
Per Claim Self Insured Portion (in Dollars)								500,000
Self Insurance Per Claim Deductible (in Dollars)									100,000
Self Insurance Reserve (in Dollars)	38,000,000	34,000,000
Prepaid Insurance (in Dollars)	$ 32,474,000	$ 29,649,000