Summary of Significant Accounting Policies - PacifiCorp - Income Taxes (Details) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015
Deferred Tax Assets and Liabilities [Line Items]
Total regulatory assets		$ 4,457	$ 4,285
Regulatory Liabilities		3,120	3,033
Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Total regulatory assets	[1]	1,754	1,577
PacifiCorp [Member]
Deferred Tax Assets and Liabilities [Line Items]
Total regulatory assets		1,543	1,685
Regulatory Liabilities		1,032	972
Deferred investment tax credit		18	23
PacifiCorp [Member] | Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Total regulatory assets	[2]	421	437
PacifiCorp [Member] | Deferred Income Tax Charge [Member]
Deferred Tax Assets and Liabilities [Line Items]
Regulatory Liabilities		$ 9	$ 12

[1] Amounts primarily represent income tax benefits related to state accelerated tax depreciation and certain property-related basis differences that were previously flowed through to customers and will be included in regulated rates when the temporary differences reverse.

[2] (1)Amounts primarily represent income tax benefits and expense related to certain property-related basis differences and other various items that PacifiCorp is required to pass on to its customers.