Commitments and Contingencies	6 Months Ended
Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings and Settlements The Partnership's subsidiaries are parties to various legal actions arising in the normal course of business. Management believes the disposition of these outstanding legal actions will not have a material impact on the Partnership's financial condition, results of operations or cash flows. Southeast Louisiana Flood Protection Litigation The Partnership and its subsidiary, Gulf South Pipeline Company, LP (Gulf South), along with approximately 100 other energy companies operating in Southern Louisiana, have been named as defendants in a petition for damages and injunctive relief in state district court for Orleans Parish, Louisiana, (Case No. 13-6911) by the Board of Commissioners of the Southeast Louisiana Flood Protection Authority - East (Flood Protection Authority). The case was filed in state court, but was removed to the U.S. District Court for the Eastern District of New Orleans (Court) in August 2013. The lawsuit claims include negligence, strict liability, public nuisance, private nuisance, breach of contract and breach of the natural servitude of drain against the defendants, alleging that the defendants’ drilling, dredging, pipeline and industrial operations since the 1930s have caused increased storm surge risk, increased flood protection costs and unspecified damages to the Flood Protection Authority. In addition to attorney fees and unspecified monetary damages, the lawsuit seeks abatement and restoration of the coastal lands, including backfilling and revegetating of canals dredged and used by the defendants, and abatement and restoration activities such as wetlands creation, reef creation, land bridge construction, hydrologic restoration, shoreline protection, structural protection, bank stabilization and ridge restoration. On February 13, 2015, the Court dismissed the case with prejudice. The Flood Protection Authority has appealed the dismissal of the case to the U.S. Court of Appeals for the Fifth Circuit in May 2015 (Case No. 15-CV-30162). On February 29, 2016, the Flood Protection Authority argued against the Court’s dismissal of the case in a hearing held before the Fifth Circuit. The Partnership is awaiting the Fifth Circuit’s issuance of a ruling on the appeal. In February 2015, Gulf South, along with other energy companies, was named a defendant in a petition for damages and injunctive relief filed by Joseph Bernstein (Case No. 744-226; 24^th Judicial District Court for the Parish of Jefferson) and the Defelice Land Company, L.L.C. (Case No. 61-926; 25^th Judicial District Court for the Parish of Plaquemines). These cases are similar in nature to the Flood Protection Authority case discussed above. Both cases were originally filed in the Louisiana state court and were removed to federal court. In the second quarter 2015, the cases were remanded to Louisiana state court. Regulatory Matters In October 2014, Gulf South filed a rate case with the Federal Energy Regulatory Commission (FERC) pursuant to Section 4 of the Natural Gas Act (Docket No. RP 15-65), requesting, among other things, a reconfiguration of the transportation rate zones on its system and, in general, an increase in its tariff rates for those customers whose agreements are at maximum tariff rates. An uncontested settlement was reached with Gulf South’s customers and FERC, which became final effective March 1, 2016. In April 2016, Gulf South settled a $16.6 million rate refund liability through a combination of cash payments and invoice credits. Also, as a result of the rate case, Gulf South implemented a fuel tracker which went into effect April 1, 2016. The Partnership applies regulatory accounting for the fuel tracker, under which the value of fuel received from customers paying the full tariff rate, and the related value of fuel used in transportation is recorded to a regulatory asset or liability depending on whether Gulf South uses more fuel than it collects from customers or collects more fuel than it uses. Prior to the implementation of the fuel tracker and the application of regulatory accounting, the value of fuel received from customers was reflected in operating revenues and the value of fuel used was reflected in operating expenses. Settlements and Insurance Proceeds In the second quarter 2016, the Partnership received $12.7 million in cash from the settlement of a legal claim which was recorded in Transportation revenues. For the three and six months ended June 30, 2015, the Partnership received $6.3 million in insurance proceeds from a business interruption claim related to Boardwalk Louisiana Midstream, LLC, which were recorded in Transportation revenues. In the second quarter 2016, the Partnership received $3.9 million related to a customer’s default of its obligations under a credit support agreement associated with the Northern Supply Access project. The proceeds were recorded in Other Liabilities and are expected to be recognized in earnings as the Partnership provides service to the customer after the Northern Supply Access project is placed in service. Environmental and Safety Matters The operating subsidiaries are subject to federal, state and local environmental laws and regulations in connection with the operation and remediation of various operating sites. As of June 30, 2016, and December 31, 2015, the Partnership had an accrued liability of approximately $5.3 million and $5.6 million related to assessment and/or remediation costs associated with the historical use of polychlorinated biphenyls, petroleum hydrocarbons and mercury, groundwater protection measures and other costs. The liability represents management’s estimate of the undiscounted future obligations based on evaluations and discussions with counsel and operating personnel and the current facts and circumstances related to these matters. The related expenditures are expected to occur over the next six years. As of June 30, 2016, and December 31, 2015, $1.7 million was recorded in Other current liabilities for each period and approximately $3.6 million and $3.9 million were recorded in Other Liabilities and Deferred Credits. Commitments for Construction The Partnership’s future capital commitments are comprised of binding commitments under purchase orders for materials ordered but not received and firm commitments under binding construction service agreements. The commitments as of June 30, 2016, were approximately $203.7 million, all of which are expected to be settled within the next twelve months. There were no substantial changes to the Partnership’s operating lease commitments, pipeline capacity agreements or capital lease obligation disclosed in Note 4 to the Partnership’s 2015 Annual Report on Form 10-K.

Commitments and Contingencies

Legal Proceedings and Settlements

The Partnership's subsidiaries are parties to various legal actions arising in the normal course of business. Management believes the disposition of these outstanding legal actions will not have a material impact on the Partnership's financial condition, results of operations or cash flows.

Southeast Louisiana Flood Protection Litigation

The Partnership and its subsidiary, Gulf South Pipeline Company, LP (Gulf South), along with approximately 100 other energy companies operating in Southern Louisiana, have been named as defendants in a petition for damages and injunctive relief in state district court for Orleans Parish, Louisiana, (Case No. 13-6911) by the Board of Commissioners of the Southeast Louisiana Flood Protection Authority - East (Flood Protection Authority). The case was filed in state court, but was removed to the U.S. District Court for the Eastern District of New Orleans (Court) in August 2013. The lawsuit claims include negligence, strict liability, public nuisance, private nuisance, breach of contract and breach of the natural servitude of drain against the defendants, alleging that the defendants’ drilling, dredging, pipeline and industrial operations since the 1930s have caused increased storm surge risk, increased flood protection costs and unspecified damages to the Flood Protection Authority. In addition to attorney fees and unspecified monetary damages, the lawsuit seeks abatement and restoration of the coastal lands, including backfilling and revegetating of canals dredged and used by the defendants, and abatement and restoration activities such as wetlands creation, reef creation, land bridge construction, hydrologic restoration, shoreline protection, structural protection, bank stabilization and ridge restoration. On February 13, 2015, the Court dismissed the case with prejudice. The Flood Protection Authority has appealed the dismissal of the case to the U.S. Court of Appeals for the Fifth Circuit in May 2015 (Case No. 15-CV-30162). On February 29, 2016, the Flood Protection Authority argued against the Court’s dismissal of the case in a hearing held before the Fifth Circuit. The Partnership is awaiting the Fifth Circuit’s issuance of a ruling on the appeal.

In February 2015, Gulf South, along with other energy companies, was named a defendant in a petition for damages and injunctive relief filed by Joseph Bernstein (Case No. 744-226; 24^th Judicial District Court for the Parish of Jefferson) and the Defelice Land Company, L.L.C. (Case No. 61-926; 25^th Judicial District Court for the Parish of Plaquemines). These cases are similar in nature to the Flood Protection Authority case discussed above. Both cases were originally filed in the Louisiana state court and were removed to federal court. In the second quarter 2015, the cases were remanded to Louisiana state court.

Regulatory Matters

In October 2014, Gulf South filed a rate case with the Federal Energy Regulatory Commission (FERC) pursuant to Section 4 of the Natural Gas Act (Docket No. RP 15-65), requesting, among other things, a reconfiguration of the transportation rate zones on its system and, in general, an increase in its tariff rates for those customers whose agreements are at maximum tariff rates. An uncontested settlement was reached with Gulf South’s customers and FERC, which became final effective March 1, 2016. In April 2016, Gulf South settled a $16.6 million rate refund liability through a combination of cash payments and invoice credits. Also, as a result of the rate case, Gulf South implemented a fuel tracker which went into effect April 1, 2016. The Partnership applies regulatory accounting for the fuel tracker, under which the value of fuel received from customers paying the full tariff rate, and the related value of fuel used in transportation is recorded to a regulatory asset or liability depending on whether Gulf South uses more fuel than it collects from customers or collects more fuel than it uses. Prior to the implementation of the fuel tracker and the application of regulatory accounting, the value of fuel received from customers was reflected in operating revenues and the value of fuel used was reflected in operating expenses.

Settlements and Insurance Proceeds

In the second quarter 2016, the Partnership received $12.7 million in cash from the settlement of a legal claim which was recorded in Transportation revenues. For the three and six months ended June 30, 2015, the Partnership received $6.3 million in insurance proceeds from a business interruption claim related to Boardwalk Louisiana Midstream, LLC, which were recorded in Transportation revenues.

In the second quarter 2016, the Partnership received $3.9 million related to a customer’s default of its obligations under a credit support agreement associated with the Northern Supply Access project. The proceeds were recorded in Other Liabilities and are expected to be recognized in earnings as the Partnership provides service to the customer after the Northern Supply Access project is placed in service.

Environmental and Safety Matters

The operating subsidiaries are subject to federal, state and local environmental laws and regulations in connection with the operation and remediation of various operating sites. As of June 30, 2016, and December 31, 2015, the Partnership had an accrued liability of approximately $5.3 million and $5.6 million related to assessment and/or remediation costs associated with the historical use of polychlorinated biphenyls, petroleum hydrocarbons and mercury, groundwater protection measures and other costs. The liability represents management’s estimate of the undiscounted future obligations based on evaluations and discussions with counsel and operating personnel and the current facts and circumstances related to these matters. The related expenditures are expected to occur over the next six years. As of June 30, 2016, and December 31, 2015, $1.7 million was recorded in Other current liabilities for each period and approximately $3.6 million and $3.9 million were recorded in Other Liabilities and Deferred Credits.

Commitments for Construction

The Partnership’s future capital commitments are comprised of binding commitments under purchase orders for materials ordered but not received and firm commitments under binding construction service agreements. The commitments as of June 30, 2016, were approximately $203.7 million, all of which are expected to be settled within the next twelve months.

There were no substantial changes to the Partnership’s operating lease commitments, pipeline capacity agreements or capital lease obligation disclosed in Note 4 to the Partnership’s 2015 Annual Report on Form 10-K.