LEGAL PROCEEDINGS, ENVIRONMENTAL MATTERS, AND OTHER EVENTS	9 Months Ended
Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
LEGAL PROCEEDINGS, ENVIRONMENTAL MATTERS, AND OTHER EVENTS	LEGAL PROCEEDINGS, ENVIRONMENTAL MATTERS, AND OTHER EVENTS The Company is involved in various legal actions arising in the ordinary course of business. The Company maintains liability insurance against certain risks arising out of the normal course of its business, subject to certain self-insured retention limits. The Company routinely establishes and reviews the adequacy of reserves for estimated legal, environmental, and self-insurance exposures. While management believes that amounts accrued in the consolidated financial statements are adequate, estimates of these liabilities may change as circumstances develop. Considering amounts recorded, routine legal matters are not expected to have a material adverse effect on the Company’s financial condition, results of operations, or cash flows; however, the Company is currently involved in certain legal proceedings, as further described below, for which the outcome and the related financial impact cannot be determined at this time. Legal Proceedings National Master Freight Agreement On November 1, 2010, ABF Freight System, Inc. filed a grievance with the National Grievance Committee, consisting of union and employer representatives established by the NMFA for resolving national contract disputes, against the following parties: the IBT; the Teamsters National Freight Industry Negotiating Committee; Trucking Management, Inc. (“TMI”); every Teamster Local Union that is party to the NMFA; and YRC Inc., New Penn Motor Express, Inc., and USF Holland, Inc. (collectively “YRC”). A lawsuit was simultaneously filed in the United States District Court for the Western Division of Arkansas (the “Trial Court”) against the parties previously named and Teamster Local Unions 373 and 878 individually and as representatives of a class of Teamsters Local Unions that are parties to the NMFA. The lawsuit sought appointment of a third-party neutral tribunal to rule on the grievance in place of the National Grievance Committee or, alternatively, for the Trial Court to rule on the lawsuit. ABF Freight System, Inc. claimed in these proceedings that the IBT and the other named parties violated the NMFA by granting certain wage and other concessions to YRC but not to ABF. The lawsuit was initially dismissed by the Trial Court on December 20, 2010 and then reinstated by the United States Court of Appeals for the Eighth Circuit (St. Louis) (the "Court of Appeals") on April 12, 2011. On July 6, 2011, the Court of Appeals reversed the Trial Court’s decision and remanded the case to the Trial Court for further proceedings. On August 1, 2012, the Trial Court dismissed the lawsuit for a second time. ABF Freight System, Inc. appealed the dismissal to the Court of Appeals, but on August 30, 2013, the Court of Appeals affirmed the Trial Court's decision to dismiss the lawsuit. ABF elected not to pursue additional appeals and the lawsuit is now concluded. Environmental Matters The Company’s subsidiaries store fuel for use in tractors and trucks in 65 underground tanks located in 20 states. Maintenance of such tanks is regulated at the federal and, in most cases, state levels. The Company believes it is in substantial compliance with all such regulations. The Company’s underground storage tanks are required to have leak detection systems. The Company is not aware of any leaks from such tanks that could reasonably be expected to have a material adverse effect on the Company. The Company has received notices from the Environmental Protection Agency and others that it has been identified as a potentially responsible party under the Comprehensive Environmental Response Compensation and Liability Act, or other federal or state environmental statutes, at several hazardous waste sites. After investigating the Company’s or its subsidiaries’ involvement in waste disposal or waste generation at such sites, the Company has either agreed to de minimis settlements or determined that its obligations, other than those specifically accrued with respect to such sites, would involve immaterial monetary liability, although there can be no assurances in this regard. At September 30, 2013 and December 31, 2012, the Company’s reserve, which was reported in accrued expenses, for estimated environmental cleanup costs of properties currently or previously operated by the Company totaled $0.9 million. Amounts accrued reflect management’s best estimate of the future undiscounted exposure related to identified properties based on current environmental regulations, management’s experience with similar environmental matters, and testing performed at certain sites.

LEGAL PROCEEDINGS, ENVIRONMENTAL MATTERS, AND OTHER EVENTS

The Company is involved in various legal actions arising in the ordinary course of business. The Company maintains liability insurance against certain risks arising out of the normal course of its business, subject to certain self-insured retention limits. The Company routinely establishes and reviews the adequacy of reserves for estimated legal, environmental, and self-insurance exposures. While management believes that amounts accrued in the consolidated financial statements are adequate, estimates of these liabilities may change as circumstances develop. Considering amounts recorded, routine legal matters are not expected to have a material adverse effect on the Company’s financial condition, results of operations, or cash flows; however, the Company is currently involved in certain legal proceedings, as further described below, for which the outcome and the related financial impact cannot be determined at this time.

Legal Proceedings

National Master Freight Agreement

On November 1, 2010, ABF Freight System, Inc. filed a grievance with the National Grievance Committee, consisting of union and employer representatives established by the NMFA for resolving national contract disputes, against the following parties: the IBT; the Teamsters National Freight Industry Negotiating Committee; Trucking Management, Inc. (“TMI”); every Teamster Local Union that is party to the NMFA; and YRC Inc., New Penn Motor Express, Inc., and USF Holland, Inc. (collectively “YRC”). A lawsuit was simultaneously filed in the United States District Court for the Western Division of Arkansas (the “Trial Court”) against the parties previously named and Teamster Local Unions 373 and 878 individually and as representatives of a class of Teamsters Local Unions that are parties to the NMFA. The lawsuit sought appointment of a third-party neutral tribunal to rule on the grievance in place of the National Grievance Committee or, alternatively, for the Trial Court to rule on the lawsuit. ABF Freight System, Inc. claimed in these proceedings that the IBT and the other named parties violated the NMFA by granting certain wage and other concessions to YRC but not to ABF. The lawsuit was initially dismissed by the Trial Court on December 20, 2010 and then reinstated by the United States Court of Appeals for the Eighth Circuit (St. Louis) (the "Court of Appeals") on April 12, 2011. On July 6, 2011, the Court of Appeals reversed the Trial Court’s decision and remanded the case to the Trial Court for further proceedings. On August 1, 2012, the Trial Court dismissed the lawsuit for a second time. ABF Freight System, Inc. appealed the dismissal to the Court of Appeals, but on August 30, 2013, the Court of Appeals affirmed the Trial Court's decision to dismiss the lawsuit. ABF elected not to pursue additional appeals and the lawsuit is now concluded.

Environmental Matters

The Company’s subsidiaries store fuel for use in tractors and trucks in 65 underground tanks located in 20 states. Maintenance of such tanks is regulated at the federal and, in most cases, state levels. The Company believes it is in substantial compliance with all such regulations. The Company’s underground storage tanks are required to have leak detection systems. The Company is not aware of any leaks from such tanks that could reasonably be expected to have a material adverse effect on the Company.

The Company has received notices from the Environmental Protection Agency and others that it has been identified as a potentially responsible party under the Comprehensive Environmental Response Compensation and Liability Act, or other federal or state environmental statutes, at several hazardous waste sites. After investigating the Company’s or its subsidiaries’ involvement in waste disposal or waste generation at such sites, the Company has either agreed to de minimis settlements or determined that its obligations, other than those specifically accrued with respect to such sites, would involve immaterial monetary liability, although there can be no assurances in this regard.

At September 30, 2013 and December 31, 2012, the Company’s reserve, which was reported in accrued expenses, for estimated environmental cleanup costs of properties currently or previously operated by the Company totaled $0.9 million. Amounts accrued reflect management’s best estimate of the future undiscounted exposure related to identified properties based on current environmental regulations, management’s experience with similar environmental matters, and testing performed at certain sites.