Regulatory Matters - PacifiCorp - Regulatory Assets (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Regulatory Assets [Line Items]
Regulatory assets		$ 130	$ 253
Regulatory assets, noncurrent		4,155	4,000
Total regulatory assets		4,285	4,253
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided		2,300	2,600
Deferred Income Tax Charge [Member]
Regulatory Assets [Line Items]
Total regulatory assets	[1]	$ 1,577	1,468
Regulatory asset amortization period years	[1]	26 years
Employee benefit plans [Member]
Regulatory Assets [Line Items]
Total regulatory assets	[2]	$ 778	747
Regulatory asset amortization period years	[2]	9 years
Unamortized contract values [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 110	123
Regulatory asset amortization period years		8 years
Deferred net power costs [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 140	277
Regulatory asset amortization period years		1 year
Unrealized loss on regulated derivative contracts [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 250	223
Regulatory asset amortization period years		5 years
PacifiCorp [Member]
Regulatory Assets [Line Items]
Regulatory assets		$ 102	131
Regulatory assets, noncurrent		1,583	1,574
Total regulatory assets		1,685	1,705
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided		1,102	1,505
PacifiCorp [Member] | Deferred Income Tax Charge [Member]
Regulatory Assets [Line Items]
Total regulatory assets	[3]	$ 437	446
Regulatory asset amortization period years	[3]	26 years
PacifiCorp [Member] | Employee benefit plans [Member]
Regulatory Assets [Line Items]
Total regulatory assets	[4]	$ 499	491
Regulatory asset amortization period years	[4]	8 years
PacifiCorp [Member] | Utah mine disposition [Member]
Regulatory Assets [Line Items]
Total regulatory assets	[5]	$ 186	194
Regulatory asset amortization period years	[5]	Various
PacifiCorp [Member] | Unamortized contract values [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 110	123
Regulatory asset amortization period years		8 years
PacifiCorp [Member] | Deferred net power costs [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 86	122
Regulatory asset amortization period years		1 year
PacifiCorp [Member] | Unrealized loss on regulated derivative contracts [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 133	85
Regulatory asset amortization period years		5 years
PacifiCorp [Member] | Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets [Line Items]
Total regulatory assets		$ 234	$ 244
Regulatory asset amortization period years		Various

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

[3] (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.

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

[5] (3)Amounts represent regulatory assets established as a result of the Utah mine disposition discussed below 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 Plan withdrawal and closure costs incurred to date considered probable of recovery.