v2.4.0.8
Litigation, Environmental and Other Contingencies Federal Energy Regulatory Commission Proceedings (Details) (Various Shippers [Member], Unfavorable Regulatory Action [Member], Federal Energy Regulatory Commission [Member], Regulated Operation [Member], USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2014
Repreations, Refunds, and Rate Reductions [Member]
Pending Litigation [Member]
SFPP [Member]
Mar. 31, 2014
Annual Rate Reductions [Member]
Pending Litigation [Member]
SFPP [Member]
Mar. 31, 2014
Revenue Subject to Refund [Member]
Pending Litigation [Member]
SFPP [Member]
Mar. 31, 2014
2008 rate case and the 2010 rate case [Member]
Opinion 517 issued and implemented (rehearing pending); and Opinion 528 issued and is awaiting filing of court document) [Member]
EPNG [Member]
Oct. 17, 2013
Pro Forma [Member]
EPNG 2010 Rate Case [Member]
Pending Litigation [Member]
EPNG [Member]
Loss Contingencies [Line Items]          
Loss Contingency, Period of Time Litigation Concerns 2 years        
Loss Contingency, Damages Sought, Value   $ 20.00 $ 100.00    
Loss Contingency, Pending Claims, Number       2  
Litigation, Court Order, Document Filing Period         60 days