Risk Management and Hedging Activities - PacifiCorp - Derivative Contract Volumes (Details) - PacifiCorp [Member] - Commodity Contract [Member] gal in Millions, MWh in Millions, Dth in Millions	Dec. 31, 2018 gal Dth MWh	Dec. 31, 2017 gal Dth MWh
Electricity purchases (sales), net, in megawatt hours [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | MWh	(6)	(9)
Natural gas purchases, in decatherms [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | Dth	(117)	(113)
Fuel purchases (in gallons) [Member]
Notional Amounts of Outstanding Derivative Positions [Line Items]
Derivative, Nonmonetary Notional Amount | gal	0	0