Commitments and Contingencies Commitments and Contingencies - PacifiCorp - Hydroelectric (Details) - PacifiCorp [Member] - Klamath Hydroelectric System [Member] $ in Millions	9 Months Ended
	Sep. 30, 2017 USD ($)
Hydroelectric [Line Items]
Dam removal cost limit	$ 200
OREGON
Hydroelectric [Line Items]
Dam removal cost limit	184
CALIFORNIA
Hydroelectric [Line Items]
Additional dam removal costs, California bond measure	250
Dam removal cost limit	$ 16