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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Regulatory Assets (Liabilities), Net, Unrealized Loss (Gain), Net, on Derivative Instruments [Line Items]
Beginning balance	$ 180	$ 253	$ 148	$ 250
Changes in fair value recognized in net regulatory assets	0	(49)	33	(13)
Net gains (losses) reclassified to operating revenue	1	(3)	14	(3)
Ending balance	162	185	162	185
PacifiCorp [Member]
Regulatory Assets (Liabilities), Net, Unrealized Loss (Gain), Net, on Derivative Instruments [Line Items]
Beginning balance	103	144	73	133
Changes in fair value recognized in net regulatory assets	6	(45)	30	(19)
Net gains (losses) reclassified to operating revenue	1	2	13	10
Net Gains (Losses) Reclassified To Cost Of Domestic Regulated Electric	(15)	(12)	(21)	(35)
Ending balance	$ 95	$ 89	$ 95	$ 89