Income Taxes - PacifiCorp - Component of Net Deferred Income Tax Liability (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	$ 1,707	$ 909
AROs	223	326
Other	448	707
Total deferred income tax assets, net	3,417	3,103
Property-related items	(9,950)	(14,237)
Regulatory assets	(651)	(1,449)
Other	(215)	(334)
Total deferred income tax liabilities	(11,659)	(16,982)
Net deferred income tax liability	(8,242)	(13,879)
PacifiCorp [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory liabilities	756	393
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits	84	202
Deferred Tax Assets, Derivative Instruments And Unamortized Contract Values	48	67
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards, State and Local	83	69
AROs	50	78
Other	50	94
Total deferred income tax assets, net	1,071	903
Property-related items	(3,381)	(5,161)
Regulatory assets	(261)	(586)
Other	(11)	(36)
Total deferred income tax liabilities	(3,653)	(5,783)
Net deferred income tax liability	$ (2,582)	$ (4,880)