Contingencies and Commitments	12 Months Ended
Dec. 31, 2012
Contingencies and Commitments [Abstract]
Contingencies and Commitments	(14) Contingencies and Commitments In June 2011, the Company as well as three other companies received correspondence from United States Environmental Protection Agency ("EPA") concerning ongoing cleanup and restoration activities under the Comprehensive Environmental Response, Compensation and Liability Act ("CERCLA") with respect to a Superfund site, the Gulfco Marine Maintenance Site ("Gulfco"), located in Freeport, Texas. In prior years, various subsidiaries of the Company utilized a successor to Gulfco to perform tank barge cleaning services, sand blasting and repair on certain Company vessels. The EPA continues to investigate activities at the site to assess additional Potentially Responsible Parties ("PRPs"). Since 2005, four named PRPs have participated in the investigation, cleanup and restoration of the site under an administrative order from EPA. Information received to date indicates that approximately $3,500,000 has been incurred in connection with the cleanup effort in addition to EPA's oversight costs of approximately $1,800,000. To date, neither the EPA nor the named PRPs have performed an allocation of potential liability in connection with the site nor have they provided requested supporting documentation for costs and expenses related to the site. The Company is investigating its activities at the site in order to assess what, if any, liability it has in connection with the site. In 2009, the Company was named a PRP in addition to a group of approximately 250 named PRPs under CERCLA with respect to a Superfund site, the Portland Harbor Superfund site ("Portland Harbor") in Portland, Oregon. The site was declared a Superfund site in December 2000 as a result of historical heavily industrialized use due to manufacturing, shipbuilding, petroleum storage and distribution, metals salvaging, and electrical power generation activities which led to contamination of Portland Harbor, an urban and industrial reach of the lower Willamette River located immediately downstream of downtown Portland. The Company's involvement arises from four spills at the site after it was declared a Superfund site, as a result of predecessor entities' actions in the area. To date, there is no information suggesting the extent of the costs or damages to be claimed from the 250 noticed PRPs. Based on the nature of the involvement at the Portland Harbor site, the Company believes its potential contribution is de minimis; however, to date neither the EPA nor the named PRPs have performed an allocation of potential liability in connection with the site nor have they provided costs and expenses in connection with the site. In 2000, the Company and a group of approximately 45 other companies were notified that they are PRPs under CERCLA with respect to a Superfund site, the Palmer Barge Line Superfund Site ("Palmer"), located in Port Arthur, Texas. In prior years, Palmer had provided tank barge cleaning services to various subsidiaries of the Company. The Company and three other PRPs entered into an agreement with the EPA to perform a remedial investigation and feasibility study and, subsequently, a limited remediation was performed and is now complete. During the 2007 third quarter, five new PRPs entered into an agreement with the EPA related to the Palmer site. In July 2008, the EPA sent a letter to approximately 30 PRPs for the Palmer site, including the Company, indicating that it intends to pursue recovery of $2,949,000 of costs it incurred in relation to the site. The Company and the other PRPs submitted recommended pro rata allocations of costs among all PRPs to the EPA and the U.S. Department of Justice ("DOJ") in order to resolve the EPA's past costs claim which is under consideration by the DOJ. In 2000, the Company and nine other companies were named as PRPs under CERCLA with respect to a Superfund site, the State Marine of Port Arthur Superfund Site ("State Marine"), located in Port Arthur, Texas. In the past, State Marine performed tank barge cleaning and services for various subsidiaries of the Company. The DOJ and EPA seek to recover reimbursement of its past costs of approximately $2,977,000 in connection with clean-up activities it incurred in relation to the site. The Company and eight other PRPs are engaged in discussions with the DOJ to negotiate a resolution of this matter. With respect to the above sites, the Company has recorded reserves, if applicable, for its estimated potential liability for its portion of the EPA's past costs claim based on information developed to date including various factors such as the Company's liability in proportion to other responsible parties and the extent to which such costs are recoverable from third parties. On July 25, 2011, a subsidiary of the Company was named as a defendant in the U.S. District Court for the Southern District of Texas - Galveston Division, in a complaint styled Figgs. v. Kirby Inland Marine, et al., which alleges that the plaintiff individually as a vessel tankerman, and on behalf of other current and former similarly situated vessel tankermen employed with the Company, is entitled to overtime pay under the Fair Labor Standards Act. Plaintiffs assert that vessel tankermen are not seamen who are expressly exempt from overtime pay provisions under the law. The case was conditionally certified as a collective action on December 22, 2011 at which time the Court prescribed a notice period for current and former employees to voluntarily participate as plaintiffs. The notice period closed on February 27, 2012. Plaintiffs seek compensatory damages in the form of back pay, attorneys' fees, cost and liquidated damages. As this matter is in the initial stage of discovery as to the merits of the case, the Company is unable to assess the liability at this time. Accordingly, the Company is not able to estimate any amount of loss or range of loss. On January 30, 2012 in the U.S. District Court for the District of New Jersey in a case styled Rescue Mission of El Paso., Inc., et al. v. John J. Nicola, et al., the Company, its subsidiary, K-Sea, and current and former officers and directors of K-Sea were named defendants in a putative class action complaint asserting that during the period of January 30, 2009 to January 27, 2010, K-Sea allegedly failed to disclose certain facts regarding K-Sea's operations and financial condition, and asserting violations of Sections 10(b)(5) and 20(a) of the Securities and Exchange Act of 1934 and Rule 10b-5 thereunder. Plaintiff seeks class certification, compensatory damages, attorneys' fees and costs. The Plaintiffs filed its Amended Consolidated Complaint on behalf of the class on July 9, 2012. The Company filed a motion to dismiss in response to the Complaint. The Company believes that this suit is without merit and intends to vigorously defend itself in this matter based on the information available to the Company at this time. The Company does not expect the outcome of this matter to have a material adverse effect on its consolidated financial statements; however, there can be no assurance as to the ultimate outcome of this matter. In addition, the Company is involved in various legal and other proceedings which are incidental to the conduct of its business, none of which in the opinion of management will have a material effect on the Company's financial condition, results of operations or cash flows. Management believes that it has recorded adequate reserves and believes that it has adequate insurance coverage or has meritorious defenses for these other claims and contingencies. Certain Significant Risks and Uncertainties. The preparation of financial statements in conformity with United States generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. However, in the opinion of management, the amounts would be immaterial. The customer base of the marine transportation segment includes the major industrial petrochemical and chemical manufacturers, agricultural chemical manufacturers and refining companies operating in the United States. During 2012, approximately 75% of marine transportation's inland revenues were from movements of such products under term contracts, ranging from one year to five years, with renewal options. During 2012, approximately 60% of the marine transportation's coastal revenues were under term contracts. While the manufacturing and refining companies have generally been customers of the Company for numerous years (some as long as 40 years) and management anticipates a continuing relationship, there is no assurance that any individual contract will be renewed. No single customer of the marine transportation segment accounted for more than 10% of the Company's revenues in 2012 and 2011. The Dow Chemical Company accounted for 12% of the Company's revenues in 2010. SeaRiver Maritime, Inc., the United States transportation affiliate of Exxon Mobil Corporation, accounted for 11% of the Company's revenues in 2010. Major customers of the diesel engine services segment include inland and offshore barge operators, oilfield service companies, oil and gas operators and producers, compression companies offshore fishing companies, marine and on-highway transportation companies, the USCG and United States Navy, and power generation, nuclear and industrial companies. The segment operates as an authorized distributor in 17 eastern states and the Caribbean, and as non-exclusive authorized service centers for Electro-Motive Diesel, Inc. ("EMD") throughout the rest of the United States for marine and power generation applications. The diesel engine services segment's relationship with EMD has been maintained for 47 years. The segment also operates factory-authorized full service marine dealerships for Cummins, Detroit Diesel and John Deere high-speed diesel engines and Allison transmissions and gears in the Gulf Coast region, as well as an authorized marine dealer for Caterpillar in Alabama, Kentucky and Louisiana. United has maintained continuous exclusive distribution rights for MTU and Allison since 1946. United is one of MTU's top five distributors of MTU off-highway engines in North America with exclusive distribution rights in Oklahoma, Arkansas, Louisiana and Mississippi. In addition, as a distributor of Allison transmission products, United has distribution rights in Oklahoma, Arkansas and Louisiana. Finally, United is also the exclusive distributor for Daimler engines and related equipment, in Oklahoma, Arkansas and Louisiana. The results of the diesel engine services segment are largely tied to the industries it serves and, therefore, can be influenced by the cycles of such industries. No single customer of the diesel engine services segment accounted for more than 10% of the Company's revenues in 2012, 2011 and 2010. Weather can be a major factor in the day-to-day operations of the marine transportation segment. Adverse weather conditions, such as high or low water, tropical storms, hurricanes, tsunamis, fog and ice, can impair the operating efficiencies of the marine fleet. Shipments of products can be delayed or postponed by weather conditions, which are totally beyond the control of the Company. Adverse water conditions are also factors which impair the efficiency of the fleet and can result in delays, diversions and limitations on night passages, and dictate horsepower requirements and size of tows. Additionally, much of the inland waterway system is controlled by a series of locks and dams designed to provide flood control, maintain pool levels of water in certain areas of the country and facilitate navigation on the inland river system. Maintenance and operation of the navigable inland waterway infrastructure is a government function handled by the Army Corps of Engineers with costs shared by industry. Significant changes in governmental policies or appropriations with respect to maintenance and operation of the infrastructure could adversely affect the Company. The Company's marine transportation segment is subject to regulation by the USCG, federal laws, state laws and certain international conventions, as well as numerous environmental regulations. The Company believes that additional safety, environmental and occupational health regulations may be imposed on the marine industry. There can be no assurance that any such new regulations or requirements, or any discharge of pollutants by the Company, will not have an adverse effect on the Company. The Company's marine transportation segment competes principally in markets subject to the Jones Act, a federal cabotage law that restricts domestic marine transportation in the United States to vessels built and registered in the United States, and manned and owned by United States citizens. The Jones Act cabotage provisions occasionally come under attack by interests seeking to facilitate foreign flag competition in trades reserved for domestic companies and vessels under the Jones Act. The Company believes that continued efforts will be made to modify or eliminate the cabotage provisions of the Jones Act. If such efforts are successful, certain elements could have an adverse effect on the Company. The Company has issued guaranties or obtained standby letters of credit and performance bonds supporting performance by the Company and its subsidiaries of contractual or contingent legal obligations of the Company and its subsidiaries incurred in the ordinary course of business. The aggregate notional value of these instruments is $35,516,000 at December 31, 2012, including $6,172,000 in letters of credit and $29,344,000 in performance bonds. All of these instruments have an expiration date within five years. The Company does not believe demand for payment under these instruments is likely and expects no material cash outlays to occur in connection with these instruments.

(14) Contingencies and Commitments

In June 2011, the Company as well as three other companies received correspondence from United States Environmental Protection Agency ("EPA") concerning ongoing cleanup and restoration activities under the Comprehensive Environmental Response, Compensation and Liability Act ("CERCLA") with respect to a Superfund site, the Gulfco Marine Maintenance Site ("Gulfco"), located in Freeport, Texas. In prior years, various subsidiaries of the Company utilized a successor to Gulfco to perform tank barge cleaning services, sand blasting and repair on certain Company vessels. The EPA continues to investigate activities at the site to assess additional Potentially Responsible Parties ("PRPs"). Since 2005, four named PRPs have participated in the investigation, cleanup and restoration of the site under an administrative order from EPA. Information received to date indicates that approximately $3,500,000 has been incurred in connection with the cleanup effort in addition to EPA's oversight costs of approximately $1,800,000. To date, neither the EPA nor the named PRPs have performed an allocation of potential liability in connection with the site nor have they provided requested supporting documentation for costs and expenses related to the site. The Company is investigating its activities at the site in order to assess what, if any, liability it has in connection with the site.

In 2009, the Company was named a PRP in addition to a group of approximately 250 named PRPs under CERCLA with respect to a Superfund site, the Portland Harbor Superfund site ("Portland Harbor") in Portland, Oregon. The site was declared a Superfund site in December 2000 as a result of historical heavily industrialized use due to manufacturing, shipbuilding, petroleum storage and distribution, metals salvaging, and electrical power generation activities which led to contamination of Portland Harbor, an urban and industrial reach of the lower Willamette River located immediately downstream of downtown Portland. The Company's involvement arises from four spills at the site after it was declared a Superfund site, as a result of predecessor entities' actions in the area. To date, there is no information suggesting the extent of the costs or damages to be claimed from the 250 noticed PRPs. Based on the nature of the involvement at the Portland Harbor site, the Company believes its potential contribution is de minimis; however, to date neither the EPA nor the named PRPs have performed an allocation of potential liability in connection with the site nor have they provided costs and expenses in connection with the site.

In 2000, the Company and a group of approximately 45 other companies were notified that they are PRPs under CERCLA with respect to a Superfund site, the Palmer Barge Line Superfund Site ("Palmer"), located in Port Arthur, Texas. In prior years, Palmer had provided tank barge cleaning services to various subsidiaries of the Company. The Company and three other PRPs entered into an agreement with the EPA to perform a remedial investigation and feasibility study and, subsequently, a limited remediation was performed and is now complete. During the 2007 third quarter, five new PRPs entered into an agreement with the EPA related to the Palmer site. In July 2008, the EPA sent a letter to approximately 30 PRPs for the Palmer site, including the Company, indicating that it intends to pursue recovery of $2,949,000 of costs it incurred in relation to the site. The Company and the other PRPs submitted recommended pro rata allocations of costs among all PRPs to the EPA and the U.S. Department of Justice ("DOJ") in order to resolve the EPA's past costs claim which is under consideration by the DOJ.

In 2000, the Company and nine other companies were named as PRPs under CERCLA with respect to a Superfund site, the State Marine of Port Arthur Superfund Site ("State Marine"), located in Port Arthur, Texas. In the past, State Marine performed tank barge cleaning and services for various subsidiaries of the Company. The DOJ and EPA seek to recover reimbursement of its past costs of approximately $2,977,000 in connection with clean-up activities it incurred in relation to the site. The Company and eight other PRPs are engaged in discussions with the DOJ to negotiate a resolution of this matter.

With respect to the above sites, the Company has recorded reserves, if applicable, for its estimated potential liability for its portion of the EPA's past costs claim based on information developed to date including various factors such as the Company's liability in proportion to other responsible parties and the extent to which such costs are recoverable from third parties.

On July 25, 2011, a subsidiary of the Company was named as a defendant in the U.S. District Court for the Southern District of Texas - Galveston Division, in a complaint styled Figgs. v. Kirby Inland Marine, et al., which alleges that the plaintiff individually as a vessel tankerman, and on behalf of other current and former similarly situated vessel tankermen employed with the Company, is entitled to overtime pay under the Fair Labor Standards Act. Plaintiffs assert that vessel tankermen are not seamen who are expressly exempt from overtime pay provisions under the law. The case was conditionally certified as a collective action on December 22, 2011 at which time the Court prescribed a notice period for current and former employees to voluntarily participate as plaintiffs. The notice period closed on February 27, 2012. Plaintiffs seek compensatory damages in the form of back pay, attorneys' fees, cost and liquidated damages. As this matter is in the initial stage of discovery as to the merits of the case, the Company is unable to assess the liability at this time. Accordingly, the Company is not able to estimate any amount of loss or range of loss.

On January 30, 2012 in the U.S. District Court for the District of New Jersey in a case styled Rescue Mission of El Paso., Inc., et al. v. John J. Nicola, et al., the Company, its subsidiary, K-Sea, and current and former officers and directors of K-Sea were named defendants in a putative class action complaint asserting that during the period of January 30, 2009 to January 27, 2010, K-Sea allegedly failed to disclose certain facts regarding K-Sea's operations and financial condition, and asserting violations of Sections 10(b)(5) and 20(a) of the Securities and Exchange Act of 1934 and Rule 10b-5 thereunder. Plaintiff seeks class certification, compensatory damages, attorneys' fees and costs. The Plaintiffs filed its Amended Consolidated Complaint on behalf of the class on July 9, 2012. The Company filed a motion to dismiss in response to the Complaint. The Company believes that this suit is without merit and intends to vigorously defend itself in this matter based on the information available to the Company at this time. The Company does not expect the outcome of this matter to have a material adverse effect on its consolidated financial statements; however, there can be no assurance as to the ultimate outcome of this matter.

In addition, the Company is involved in various legal and other proceedings which are incidental to the conduct of its business, none of which in the opinion of management will have a material effect on the Company's financial condition, results of operations or cash flows. Management believes that it has recorded adequate reserves and believes that it has adequate insurance coverage or has meritorious defenses for these other claims and contingencies.

Certain Significant Risks and Uncertainties. The preparation of financial statements in conformity with United States generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. However, in the opinion of management, the amounts would be immaterial.

The customer base of the marine transportation segment includes the major industrial petrochemical and chemical manufacturers, agricultural chemical manufacturers and refining companies operating in the United States. During 2012, approximately 75% of marine transportation's inland revenues were from movements of such products under term contracts, ranging from one year to five years, with renewal options. During 2012, approximately 60% of the marine transportation's coastal revenues were under term contracts. While the manufacturing and refining companies have generally been customers of the Company for numerous years (some as long as 40 years) and management anticipates a continuing relationship, there is no assurance that any individual contract will be renewed. No single customer of the marine transportation segment accounted for more than 10% of the Company's revenues in 2012 and 2011. The Dow Chemical Company accounted for 12% of the Company's revenues in 2010. SeaRiver Maritime, Inc., the United States transportation affiliate of Exxon Mobil Corporation, accounted for 11% of the Company's revenues in 2010.

Major customers of the diesel engine services segment include inland and offshore barge operators, oilfield service companies, oil and gas operators and producers, compression companies offshore fishing companies, marine and on-highway transportation companies, the USCG and United States Navy, and power generation, nuclear and industrial companies. The segment operates as an authorized distributor in 17 eastern states and the Caribbean, and as non-exclusive authorized service centers for Electro-Motive Diesel, Inc. ("EMD") throughout the rest of the United States for marine and power generation applications. The diesel engine services segment's relationship with EMD has been maintained for 47 years. The segment also operates factory-authorized full service marine dealerships for Cummins, Detroit Diesel and John Deere high-speed diesel engines and Allison transmissions and gears in the Gulf Coast region, as well as an authorized marine dealer for Caterpillar in Alabama, Kentucky and Louisiana.

United has maintained continuous exclusive distribution rights for MTU and Allison since 1946. United is one of MTU's top five distributors of MTU off-highway engines in North America with exclusive distribution rights in Oklahoma, Arkansas, Louisiana and Mississippi. In addition, as a distributor of Allison transmission products, United has distribution rights in Oklahoma, Arkansas and Louisiana. Finally, United is also the exclusive distributor for Daimler engines and related equipment, in Oklahoma, Arkansas and Louisiana.

The results of the diesel engine services segment are largely tied to the industries it serves and, therefore, can be influenced by the cycles of such industries. No single customer of the diesel engine services segment accounted for more than 10% of the Company's revenues in 2012, 2011 and 2010.

Weather can be a major factor in the day-to-day operations of the marine transportation segment. Adverse weather conditions, such as high or low water, tropical storms, hurricanes, tsunamis, fog and ice, can impair the operating efficiencies of the marine fleet. Shipments of products can be delayed or postponed by weather conditions, which are totally beyond the control of the Company. Adverse water conditions are also factors which impair the efficiency of the fleet and can result in delays, diversions and limitations on night passages, and dictate horsepower requirements and size of tows. Additionally, much of the inland waterway system is controlled by a series of locks and dams designed to provide flood control, maintain pool levels of water in certain areas of the country and facilitate navigation on the inland river system. Maintenance and operation of the navigable inland waterway infrastructure is a government function handled by the Army Corps of Engineers with costs shared by industry. Significant changes in governmental policies or appropriations with respect to maintenance and operation of the infrastructure could adversely affect the Company.

The Company's marine transportation segment is subject to regulation by the USCG, federal laws, state laws and certain international conventions, as well as numerous environmental regulations. The Company believes that additional safety, environmental and occupational health regulations may be imposed on the marine industry. There can be no assurance that any such new regulations or requirements, or any discharge of pollutants by the Company, will not have an adverse effect on the Company.

The Company's marine transportation segment competes principally in markets subject to the Jones Act, a federal cabotage law that restricts domestic marine transportation in the United States to vessels built and registered in the United States, and manned and owned by United States citizens. The Jones Act cabotage provisions occasionally come under attack by interests seeking to facilitate foreign flag competition in trades reserved for domestic companies and vessels under the Jones Act. The Company believes that continued efforts will be made to modify or eliminate the cabotage provisions of the Jones Act. If such efforts are successful, certain elements could have an adverse effect on the Company.

The Company has issued guaranties or obtained standby letters of credit and performance bonds supporting performance by the Company and its subsidiaries of contractual or contingent legal obligations of the Company and its subsidiaries incurred in the ordinary course of business. The aggregate notional value of these instruments is $35,516,000 at December 31, 2012, including $6,172,000 in letters of credit and $29,344,000 in performance bonds. All of these instruments have an expiration date within five years. The Company does not believe demand for payment under these instruments is likely and expects no material cash outlays to occur in connection with these instruments.