Risk Management and Hedging Activities - PacifiCorp - Not Designated as Hedging Contracts (Details) - PacifiCorp [Member] - Not Designated as Hedging Instrument [Member] - Commodity derivative [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Regulatory Assets (Liabilities), Net, Unrealized Loss (Gain), Net, on Derivative Instruments [Line Items]
Beginning balance	$ 122	$ 103	$ 101	$ 73
Changes in fair value recognized in net regulatory assets	6	6	34	30
Net (losses) gains reclassified to operating revenue	(1)	1	6	13
Net Gains (Losses) Reclassified To Cost Of Domestic Regulated Electric	(11)	(15)	(25)	(21)
Ending balance	$ 116	$ 95	$ 116	$ 95