Guarantees	12 Months Ended
Dec. 31, 2016
Guarantees [Abstract]
Guarantees	Guarantees In connection with the sale of its NORESCO domestic operations in December 2005, the Company agreed to maintain in place guarantees of certain warranty obligations of NORESCO. The savings guarantees provided that once the energy-efficiency construction was completed by NORESCO, the customer would experience a certain dollar amount of energy savings over a period of years. The undiscounted maximum aggregate payments that may be due related to these guarantees were approximately $115 million as of December 31, 2016, extending at a decreasing amount for approximately 12 years. As of December 31, 2016, EQM had issued a $91 million performance guarantee (the Initial Guarantee) in connection with the obligations of MVP Holdco to fund its proportionate share of the construction budget for the MVP. Upon the FERC’s initial release to begin construction of the MVP, the Initial Guarantee will terminate, and EQM will be obligated to issue a new guarantee in an amount equal to 33% of MVP Holdco’s remaining obligations to make capital contributions to the MVP Joint Venture in connection with the then remaining construction budget, less, subject to certain limits, any credit assurances issued by an affiliate of EQM under such affiliate's precedent agreement with the MVP Joint Venture.

Guarantees

In connection with the sale of its NORESCO domestic operations in December 2005, the Company agreed to maintain in place guarantees of certain warranty obligations of NORESCO. The savings guarantees provided that once the energy-efficiency construction was completed by NORESCO, the customer would experience a certain dollar amount of energy savings over a period of years. The undiscounted maximum aggregate payments that may be due related to these guarantees were approximately $115 million as of December 31, 2016, extending at a decreasing amount for approximately 12 years.

As of December 31, 2016, EQM had issued a $91 million performance guarantee (the Initial Guarantee) in connection with the obligations of MVP Holdco to fund its proportionate share of the construction budget for the MVP. Upon the FERC’s initial release to begin construction of the MVP, the Initial Guarantee will terminate, and EQM will be obligated to issue a new guarantee in an amount equal to 33% of MVP Holdco’s remaining obligations to make capital contributions to the MVP Joint Venture in connection with the then remaining construction budget, less, subject to certain limits, any credit assurances issued by an affiliate of EQM under such affiliate's precedent agreement with the MVP Joint Venture.