Employee Benefit Plans - PacifiCorp - Multiemployer and Joint Trust Pension Plans (Details) - PacifiCorp [Member] - USD ($) $ in Millions		12 Months Ended
		Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Joint Trustee Plan, Percentage By Which Joint Trustee Plan was at Least Funded				80.00%		80.00%
Joint Trustee Plan, Period Contributions	[1]		$ 8		$ 9		$ 9
UMWA Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Multiemployer Plans, Withdrawal Obligation, Most Recent Estimate			97
Multiemployer Plans, Certified Zone Status				Red		Orange
Multiemployer Plan, Period Contributions	[1]		$ 1		$ 2		$ 3
Subsequent Event [Member]
Defined Benefit Plan Disclosure [Line Items]
Joint Trustee Plan, Percentage By Which Joint Trustee Plan was at Least Funded		80.00%
Subsequent Event [Member] | UMWA Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Multiemployer Plans, Certified Zone Status		Red

[1] PacifiCorp's and Energy West Mining Company's minimum contributions to the plans are based on the amount of wages paid to employees covered by the Local 57 Trust Fund collective bargaining agreements and the number of mining hours worked for the UMWA 1974 Pension Plan, respectively, subject to ERISA minimum funding requirements. As a result of the plan's critical status, Energy West Mining Company was required to begin paying a surcharge for hours worked on and after December 1, 2014.