Summary of Significant Accounting Policies - PacifiCorp - Income Taxes (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate		21.00%	35.00%	35.00%
Total regulatory assets		$ 3,067	$ 2,950
Regulatory Liabilities		7,506	7,511
Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Total regulatory assets	[1]	196	143
Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory Liabilities	[2]	$ 3,923	$ 4,143
PacifiCorp [Member]
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate		21.00%	35.00%	35.00%
Total regulatory assets		$ 1,112	$ 1,061
Regulatory Liabilities		3,055	3,071
Deferred investment tax credit		13	16
PacifiCorp [Member] | Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory Liabilities	[3]	$ 1,803	$ 1,960
Tax Cuts and Jobs Act of 2017 [Member]
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate		21.00%
Tax Cuts and Jobs Act of 2017 [Member] | Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory Liabilities	[4]	$ 5,950
Tax Cuts and Jobs Act of 2017 [Member] | PacifiCorp [Member]
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate		21.00%
Tax Cuts and Jobs Act of 2017 [Member] | PacifiCorp [Member] | Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory Liabilities	[4]	$ 8

[1] Amounts primarily represent income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.

[2] (1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 11 for further discussion of 2017 Tax Reform impacts.

[3] (2)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. See Note 8 for further discussion of 2017 Tax Reform.

[4] (1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse. Amount includes regulatory liabilities with an indeterminate life of $82 million as of December 31, 2018. See Note 9 for further discussion of 2017 Tax Reform impacts.