Common Shareholder's Equity - PacifiCorp (Details) - PacifiCorp [Member] - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Feb. 28, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Dividends, Common Stock, Cash		$ 600	$ 875	$ 950
Minimum Common Equity To Capitalization Percentage		44.00%
Percentage of preferred stock to be treated as common equity for common equity percentage calculation		50.00%
Actual common equity percentage as calculated in accordance with acquisition commitment		54.00%
Amount available for dividend distribution without prior approval		$ 2,500
Subsequent Event [Member]
Class of Stock [Line Items]
Dividends, Common Stock, Cash	$ 250