Litigation, Environmental and Other Contingencies Federal Energy Regulatory Commission Proceedings (Details) - Federal Energy Regulatory Commission [Member] - Various Shippers [Member] - Unfavorable Regulatory Action [Member] $ in Millions |
12 Months Ended |
---|---|
Dec. 31, 2016
USD ($)
| |
EPNG [Member] | Opinion 517 issued and implemented (rehearing pending); and Opinion 528 issued. [Member] | |
EPNG [Abstract] | |
Loss Contingency, Pending Claims, Number | 2 |
Repreations, Refunds, and Rate Reductions [Member] | SFPP [Member] | Pending Litigation [Member] | |
Loss Contingencies [Line Items] | |
Loss Contingency Period of Time Litigation Concerns | 2 years |
Annual Rate Reductions [Member] | SFPP [Member] | Pending Litigation [Member] | |
SFPP [Abstract] | |
Loss Contingency, Damages Sought, Value | $ 40 |
Revenue Subject to Refund [Member] | SFPP [Member] | Pending Litigation [Member] | |
SFPP [Abstract] | |
Loss Contingency, Damages Sought, Value | $ 190 |