Risk Management and Hedging Activities - PacifiCorp - Not Designated as Hedging Contracts (Details) - Not Designated as Hedging Instrument [Member] - Commodity derivative [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Regulatory Assets (Liabilities), Net, Unrealized Loss (Gain), Net, on Derivative Instruments [Line Items]
Beginning balance	$ 250	$ 223
Changes in fair value recognized in net regulatory assets	36	60
Net gains reclassified to operating revenue	0	9
Ending balance	253	255
PacifiCorp [Member]
Regulatory Assets (Liabilities), Net, Unrealized Loss (Gain), Net, on Derivative Instruments [Line Items]
Beginning balance	133	85
Changes in fair value recognized in net regulatory assets	26	48
Net gains reclassified to operating revenue	8	25
Net Gains (Losses) Reclassified To Cost Of Domestic Regulated Electric	(23)	(28)
Ending balance	$ 144	$ 130