Commitments And Contingencies (Nuclear Insurance) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)
Long-term Purchase Commitment [Line Items]
Humboldt Bay Unit 3 potential premium obligation	$ 60
Coverage for purchased public liability insurance, per incident	375
Diablo Canyon [Member]
Long-term Purchase Commitment [Line Items]
Maximum public liability per nuclear incident under Price-Anderson Act	13,500
Maximum available public liability insurance for Diablo Canyon as required by Price-Anderson Act	375
Maximum total payment incurred per event under the loss sharing program	255
Maximum annual payment incurred per event under the loss sharing program	38
Diablo Canyon [Member] | Nuclear Incident [Member]
Long-term Purchase Commitment [Line Items]
Amount of property damage and business interruption coverage provided by NEIL for Diablo Canyon	3,500
Diablo Canyon [Member] | Non Nuclear Incident [Member]
Long-term Purchase Commitment [Line Items]
Amount of property damage and business interruption coverage provided by NEIL for Diablo Canyon	2,800
Humboldt Bay Unit [Member]
Long-term Purchase Commitment [Line Items]
Amount of property damage coverage provided by NEIL	131
Amount of indemnification from the NRC for public liability arising from nuclear incidents	500
Amount of liability insurance for Humboldt bay Unit 3	$ 53