Regulatory Matters Regulatory Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Regulatory Assets [Line Items]
Current regulatory assets	$ 131		$ 94
Noncurrent regulatory assets	1,574		1,290
Total regulatory assets	1,705		1,384
Regulatory assets not earning a return on investment	1,505		1,244
Deferred income taxes [Member]
Regulatory Assets [Line Items]
Weighted Average Remaining Life	26 years	[1]
Total regulatory assets	446	[1]	461	[1]
Employee benefit plans [Member]
Regulatory Assets [Line Items]
Weighted Average Remaining Life	8 years	[2]
Total regulatory assets	491	[2]	390	[2]
Utah mine disposition [Member]
Regulatory Assets [Line Items]
Weighted Average Remaining Life	Various	[3]
Total regulatory assets	194	[3]	0	[3]
Unamortized contract values [Member]
Regulatory Assets [Line Items]
Weighted Average Remaining Life	8 years
Total regulatory assets	123		146
Deferred net power costs [Member]
Regulatory Assets [Line Items]
Weighted Average Remaining Life	1 year
Total regulatory assets	122		139
Unrealized loss on derivative contracts [Member]
Regulatory Assets [Line Items]
Weighted Average Remaining Life	4 years
Total regulatory assets	85		55
Other [Member]
Regulatory Assets [Line Items]
Weighted Average Remaining Life	Various
Total regulatory assets	$ 244		$ 193

[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.

[2] Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in rates when recognized.

[3] Amounts represent regulatory assets established as a result of the Utah Mine Disposition for the net property, plant and equipment not considered probable of disallowance and for the portion of losses associated with the assets held for sale, UMWA 1974 Pension Trust withdrawal and closure costs incurred to date considered probable of recovery.