Other (Notes)	12 Months Ended
Dec. 31, 2014
Other Income and Expenses [Abstract]
Other	OTHER During 2014 and 2012, we capitalized $3.5 million and $11.1 million, respectively, of project feasibility costs associated with the various projects, which had been expensed in prior periods in Other expense, net, upon determining that the projects were probable of development. We detected a leak in an underground cavern at our Eminence Storage Field in Mississippi on December 28, 2010. During 2014, 2013 and 2012, we recorded $0.8 million, $4.3 million and $2.5 million, respectively, of charges to Operation and maintenance expenses primarily related to costs to ensure the safety of the surrounding area. Due to the abandonment and retirement of four of the seven caverns at our Eminence Storage Field in 2013 and the expected recovery of such costs in our rates, we reclassified $92 million of costs related to the Eminence ARO from Total property, plant and equipment, net to Regulatory assets (Eminence abandonment regulatory asset). Included in Other expense, net, for the year 2013, consistent with the Agreement in our Docket No. RP12-993 general rate case proceeding, was a charge of $11.5 million, related to the estimated portion of the Eminence abandonment regulatory asset that will not be recovered in rates; which was reduced by $2.9 million in 2014 upon completion of the abandonment. We also recognized income during 2013 of $16.1 million, related to insurance recoveries associated with this event.

OTHER

During 2014 and 2012, we capitalized $3.5 million and $11.1 million, respectively, of project feasibility costs associated with the various projects, which had been expensed in prior periods in Other expense, net, upon determining that the projects were probable of development.

We detected a leak in an underground cavern at our Eminence Storage Field in Mississippi on December 28, 2010. During 2014, 2013 and 2012, we recorded $0.8 million, $4.3 million and $2.5 million, respectively, of charges to Operation and maintenance expenses primarily related to costs to ensure the safety of the surrounding area.

Due to the abandonment and retirement of four of the seven caverns at our Eminence Storage Field in 2013 and the expected recovery of such costs in our rates, we reclassified $92 million of costs related to the Eminence ARO from Total property, plant and equipment, net to Regulatory assets (Eminence abandonment regulatory asset). Included in Other expense, net, for the year 2013, consistent with the Agreement in our Docket No. RP12-993 general rate case proceeding, was a charge of $11.5 million, related to the estimated portion of the Eminence abandonment regulatory asset that will not be recovered in rates; which was reduced by $2.9 million in 2014 upon completion of the abandonment. We also recognized income during 2013 of $16.1 million, related to insurance recoveries associated with this event.