Summary of Significant Accounting Policies - PacifiCorp - Income Taxes (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Total regulatory assets		$ 2,950	$ 4,457
Regulatory Liabilities		7,511	3,120
Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Total regulatory assets	[1]	143	1,754
Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory Liabilities	[2]	$ 4,143	$ 25
PacifiCorp [Member]
Deferred Tax Assets and Liabilities [Line Items]
Federal statutory income tax rate		35.00%	35.00%	35.00%
Total regulatory assets		$ 1,061	$ 1,543
Regulatory Liabilities		3,071	1,032
Deferred investment tax credit		16	18
PacifiCorp [Member] | Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Total regulatory assets	[3]	0	421
PacifiCorp [Member] | Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory Liabilities		$ 1,960	$ 9
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		$ 2,358

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

[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. See Note 10 for further discussion of 2017 Tax Reform impacts.