Regulatory Matters	12 Months Ended
Dec. 31, 2012
Regulated Operations [Abstract]
Public Utilities Disclosure [Text Block]	Regulatory Matters The tariffs we charge for transportation on our interstate common carrier pipelines are subject to rate regulation by the FERC, under the Interstate Commerce Act. The Interstate Commerce Act requires, among other things, that interstate petroleum products pipeline rates be just and reasonable and nondiscriminatory. Pursuant to FERC Order No. 561, effective January 1, 1995, interstate petroleum products pipelines are able to change their rates within prescribed ceiling levels that are tied to an inflation index. FERC Order No. 561-A, affirming and clarifying Order No. 561, expanded the circumstances under which interstate petroleum products pipelines may employ cost-of-service ratemaking in lieu of the indexing methodology, effective January 1, 1995. For each of the years ended December 31, 2012, 2011 and 2010, the application of the indexing methodology did not significantly affect tariff rates on our interstate petroleum products pipelines. Below is a brief description of our ongoing regulatory matters, including any material developments that occurred during 2012. TGP’s Proposed Sale of Production Area Facilities On July 26, 2012, TGP filed an application with the FERC seeking authority to abandon by sale certain offshore and onshore supply facilities as well as a related offer of settlement that addresses the proposed rate and accounting treatment associated with the sale. The offer of settlement provides for a rate adjustment to TGP’s maximum tariff rates upon the transfer of the assets and the establishment of a regulatory asset for a portion of the unrecovered net book value of the facilities to be sold. The sale is conditioned on approval by the FERC of both the requested abandonment authorization and offer of settlement. As of December 31, 2012, these assets totaled $32 million and are included within “Assets held for sale” in our accompanying consolidated balance sheet. Additionally, we have recorded an approximately $113 million regulatory asset, which is included within “Deferred charges and other assets” in our accompanying consolidated balance sheet as of December 31, 2012, for the portion of the loss that we expect to recover through TGP’s jurisdictional transportation rates as outlined in the FERC filing. TGP Northeast Supply Diversification Project (Docket No. CP11-30-000) On September 10, 2011, the FERC issued an order authorizing the expansion of TGP’s pipeline facilities in northern Pennsylvania and western New York along with an associated lease of transportation capacity from Dominion Transmission, Inc. in order to provide incremental firm transportation service to shippers of approximately 245 million cubic feet per day of natural gas produced in the Marcellus Shale supply area to northeast markets. The estimated capital cost of the project is approximately $55 million and the capacity is fully subscribed under long-term contracts. The project was completed and placed into service on November 1, 2012. TGP Northeast Upgrade Project (Docket No. CP11-161-000) On May 29, 2012, the FERC issued an order authorizing the expansion of TGP’s pipeline facilities in Pennsylvania and New Jersey that will provide needed infrastructure to support continued development of Marcellus shale natural gas production and increase TGP’s delivery capacity in the region by approximately 620 million cubic feet per day. The estimated capital cost of the project is approximately $450 million and the capacity is fully subscribed under long term contracts. With no stay of construction granted, and subject to receipt of final FERC and other regulatory agency approvals, the project is anticipated to be placed in service in November 1, 2013. TGP MPP Project (Docket No. CP12-28-000) On August 9, 2012, the FERC issued an order authorizing the expansion of TGP’s pipeline facilities in northwestern Pennsylvania that will provide needed infrastructure to support continued development of Marcellus shale natural gas production and increase TGP’s delivery capacity in the region by approximately 240 million cubic feet per day. The estimated capital cost of the project is approximately $86 million, and the capacity is fully subscribed under long term contracts. The Marcellus Pooling project is anticipated to be placed in service in November 1, 2013. TGP Rose Lake Expansion Project (Docket No. CP13-03-000) On October 10, 2012, TGP filed an application with the FERC requesting authority to expand its pipeline capacity in northern Pennsylvania through the installation and modification of new and existing compression facilities that will result in increased capacity of approximately 225 million cubic feet per day and will improve the efficiency and reduce emissions by replacing certain older existing compression facilities. The project will further support continued development of Marcellus shale natural gas production in the region. The estimated capital cost of the project is approximately $92 million and the capacity is fully subscribed under long term contracts. The project is anticipated to be placed in service in November 1, 2014. EPNG Sierrita Natural Gas Pipeline LLC Project On February 7, 2013, our wholly-owned subsidiary Sierrita Gas Pipeline LLC (a newly created interstate natural gas pipeline company) filed an application with the FERC to build a new 60-mile, 36-inch diameter pipeline that would extend from EPNG’s existing south mainlines (near the City of Tucson, Arizona) to the U.S.-Mexico border (near the Town of Sasabe, Arizona). At an approximate cost of $200 million, the new Sierrita Pipeline would interconnect with a new 36-inch diameter natural gas pipeline to be built in Mexico. The new facilities will provide approximately 200 million cubic feet per day of firm natural gas transportation capacity. Sierrita Gas Pipeline LLC entered into a 25-year transportation service agreement for the entire capacity. Pending FERC approval, the construction of the Sierrita Pipeline would begin as early as the first quarter of 2014. We anticipate that the pipeline would be placed into service in the fall of 2014. Products Pipelines and Natural Gas Pipelines Regulatory Proceedings For information on our pipeline regulatory proceedings, see Note 16 “Litigation, Environmental and Other Contingencies—Federal Energy Regulatory Commission Proceedings” and “—California Public Utilities Commission Proceedings.”

Regulatory Matters

The tariffs we charge for transportation on our interstate common carrier pipelines are subject to rate regulation by the FERC, under the Interstate Commerce Act. The Interstate Commerce Act requires, among other things, that interstate petroleum products pipeline rates be just and reasonable and nondiscriminatory. Pursuant to FERC Order No. 561, effective January 1, 1995, interstate petroleum products pipelines are able to change their rates within prescribed ceiling levels that are tied to an inflation index. FERC Order No. 561-A, affirming and clarifying Order No. 561, expanded the circumstances under which interstate petroleum products pipelines may employ cost-of-service ratemaking in lieu of the indexing methodology, effective January 1, 1995. For each of the years ended December 31, 2012, 2011 and 2010, the application of the indexing methodology did not significantly affect tariff rates on our interstate petroleum products pipelines.

Below is a brief description of our ongoing regulatory matters, including any material developments that occurred during 2012.

TGP’s Proposed Sale of Production Area Facilities

On July 26, 2012, TGP filed an application with the FERC seeking authority to abandon by sale certain offshore and

onshore supply facilities as well as a related offer of settlement that addresses the proposed rate and accounting treatment

associated with the sale. The offer of settlement provides for a rate adjustment to TGP’s maximum tariff rates upon the transfer of the assets and the establishment of a regulatory asset for a portion of the unrecovered net book value of the facilities to be sold. The sale is conditioned on approval by the FERC of both the requested abandonment authorization and offer of settlement. As of December 31, 2012, these assets totaled $32 million and are included within “Assets held for sale” in our accompanying consolidated balance sheet. Additionally, we have recorded an approximately $113 million regulatory asset, which is included within “Deferred charges and other assets” in our accompanying consolidated balance sheet as of December 31, 2012, for the portion of the loss that we expect to recover through TGP’s jurisdictional transportation rates as outlined in the FERC filing.

TGP Northeast Supply Diversification Project (Docket No. CP11-30-000)

On September 10, 2011, the FERC issued an order authorizing the expansion of TGP’s pipeline facilities in northern Pennsylvania and western New York along with an associated lease of transportation capacity from Dominion Transmission, Inc. in order to provide incremental firm transportation service to shippers of approximately 245 million cubic feet per day of natural gas produced in the Marcellus Shale supply area to northeast markets. The estimated capital cost of the project is approximately $55 million and the capacity is fully subscribed under long-term contracts. The project was completed and placed into service on November 1, 2012.

TGP Northeast Upgrade Project (Docket No. CP11-161-000)

On May 29, 2012, the FERC issued an order authorizing the expansion of TGP’s pipeline facilities in Pennsylvania and New Jersey that will provide needed infrastructure to support continued development of Marcellus shale natural gas production and increase TGP’s delivery capacity in the region by approximately 620 million cubic feet per day. The estimated capital cost of the project is approximately $450 million and the capacity is fully subscribed under long term contracts. With no stay of construction granted, and subject to receipt of final FERC and other regulatory agency approvals, the project is anticipated to be placed in service in November 1, 2013.

TGP MPP Project (Docket No. CP12-28-000)

On August 9, 2012, the FERC issued an order authorizing the expansion of TGP’s pipeline facilities in northwestern Pennsylvania that will provide needed infrastructure to support continued development of Marcellus shale natural gas production and increase TGP’s delivery capacity in the region by approximately 240 million cubic feet per day. The estimated capital cost of the project is approximately $86 million, and the capacity is fully subscribed under long term contracts. The Marcellus Pooling project is anticipated to be placed in service in November 1, 2013.

TGP Rose Lake Expansion Project (Docket No. CP13-03-000)

On October 10, 2012, TGP filed an application with the FERC requesting authority to expand its pipeline capacity in northern Pennsylvania through the installation and modification of new and existing compression facilities that will result in increased capacity of approximately 225 million cubic feet per day and will improve the efficiency and reduce emissions by replacing certain older existing compression facilities. The project will further support continued development of Marcellus shale natural gas production in the region. The estimated capital cost of the project is approximately $92 million and the capacity is fully subscribed under long term contracts. The project is anticipated to be placed in service in November 1, 2014.

EPNG Sierrita Natural Gas Pipeline LLC Project

On February 7, 2013, our wholly-owned subsidiary Sierrita Gas Pipeline LLC (a newly created interstate natural gas pipeline company) filed an application with the FERC to build a new 60-mile, 36-inch diameter pipeline that would extend from EPNG’s existing south mainlines (near the City of Tucson, Arizona) to the U.S.-Mexico border (near the Town of Sasabe, Arizona). At an approximate cost of $200 million, the new Sierrita Pipeline would interconnect with a new 36-inch diameter natural gas pipeline to be built in Mexico. The new facilities will provide approximately 200 million cubic feet per day of firm natural gas transportation capacity. Sierrita Gas Pipeline LLC entered into a 25-year transportation service agreement for the entire capacity. Pending FERC approval, the construction of the Sierrita Pipeline would begin as early as the first quarter of 2014. We anticipate that the pipeline would be placed into service in the fall of 2014.

Products Pipelines and Natural Gas Pipelines Regulatory Proceedings

For information on our pipeline regulatory proceedings, see Note 16 “Litigation, Environmental and Other Contingencies—Federal Energy Regulatory Commission Proceedings” and “—California Public Utilities Commission Proceedings.”