Note 1. Summary of Significant Accounting Policies (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Assets (in Dollars)	490,623,000	470,579,000
Liabilities (in Dollars)	158,700,000	150,220,000
Letters of Credit Outstanding, Amount (in Dollars)	7,400,000
Number of Operating Segments	6	6
Number of Reportable Segments	2	2
Customer 1 [Member] | Accounts Receivable [Member]
Concentration Risk, Percentage		11.00%
Customer 1 [Member]
Entity-Wide Revenue, Major Customer, Percentage	9.00%	11.00%	18.00%
Customer 2 [Member] | Accounts Receivable [Member]
Concentration Risk, Percentage		8.00%
Customer 2 [Member]
Entity-Wide Revenue, Major Customer, Percentage		10.00%	10.00%
Insurance Claims [Member]
Letters of Credit Outstanding, Amount (in Dollars)	7,400,000
Tractors [Member]
Property, Plant and Equipment, Useful Life	5 years
Property, Plant and Equipment, Salvage Value, Percentage	25.00%
Trailers [Member]
Property, Plant and Equipment, Useful Life	7 years
Property, Plant and Equipment, Salvage Value, Percentage	35.00%
Service and other equipment [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life	3 years
Service and other equipment [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life	15 years
Building and Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life	20 years
Building and Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life	40 years
Tires In Service [Member]
Property, Plant and Equipment, Useful Life	24 months
Geographic Concentration Risk [Member] | United States [Member] | Revenue [Member]
Concentration Risk, Percentage	99.00%
MWL [Member]
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions	45.00%
Assets (in Dollars)	5,200,000
Liabilities (in Dollars)	2,700,000