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		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Regulatory Assets (Liabilities), Net, Unrealized Loss (Gain), Net, on Derivative Instruments [Line Items]
Beginning balance	$ 185	$ 233	$ 250	$ 223
Changes in fair value recognized in net regulatory assets	18	47	5	104
Net losses reclassified to operating revenue	(3)	(11)	(6)	(4)
Ending balance	195	253	195	253
PacifiCorp [Member]
Regulatory Assets (Liabilities), Net, Unrealized Loss (Gain), Net, on Derivative Instruments [Line Items]
Beginning balance	89	99	133	85
Changes in fair value recognized in net regulatory assets	15	38	(4)	65
Net losses reclassified to operating revenue	(2)	1	8	29
Net Gains (Losses) Reclassified To Cost Of Domestic Regulated Electric	0	(10)	(35)	(51)
Ending balance	$ 102	$ 128	$ 102	$ 128