Short-Term Debt and Credit Facilities - PacifiCorp - Credit Facility (Details) $ in Millions		Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	[1]	$ 6,421	$ 6,696
Short-term Debt	[1]	(974)	(1,445)
Line of Credit Facility, Amounts Supported	[1]	(415)	(625)
Line of Credit Facility, Remaining Borrowing Capacity	[1]	5,032	4,626
PacifiCorp [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		1,200	1,200
Short-term Debt		(20)	(20)
Line of Credit Facility, Amounts Supported		(160)	(398)
Line of Credit Facility, Remaining Borrowing Capacity		1,020	782
Letters of Credit Outstanding, Amount		$ 310	$ 451
PacifiCorp [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Debt, Weighted Average Interest Rate		0.65%	0.43%
Debt to capitalization ratio		0.65
PacifiCorp [Member] | Commercial Paper [Member]
Line of Credit Facility [Line Items]
Debt, Weighted Average Interest Rate		0.65%	0.43%
PacifiCorp [Member] | Letter of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Amounts Supported		$ (10)	$ (270)
PacifiCorp [Member] | Unsecured credit facility, $600 million, expiring June 2017 [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		600
PacifiCorp [Member] | Unsecured credit facility, $600 million, expiring March 2018 [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		600
PacifiCorp [Member] | Certain transactions required by third parties [Member]
Line of Credit Facility [Line Items]
Letters of Credit Outstanding, Amount		15
PacifiCorp [Member] | Tax exempt bond obligations and commodity contract collateral requirement [Member]
Line of Credit Facility [Line Items]
Letters of Credit Outstanding, Amount		$ 310	$ 451

[1] The above table does not include unused credit facilities and letters of credit for investments that are accounted for under the equity method.