Jointly Owned Utility Facilities Jointly Owned Utility Facilities (Details) (USD $) In Millions, unless otherwise specified															12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Jim Bridger Nos. 1-4 [Member]	Dec. 31, 2013 Hunter No. 1 [Member]	Dec. 31, 2013 Hunter No. 2 [Member]	Dec. 31, 2013 Wyodak [Member]	Dec. 31, 2013 Colstrip Nos. 3 and 4 [Member]	Dec. 31, 2013 Hermiston [Member]		Dec. 31, 2013 Craig Nos. 1 and 2 [Member]		Dec. 31, 2013 Hayden No. 1 [Member]	Dec. 31, 2013 Hayden No. 2 [Member]	Dec. 31, 2013 Foote Creek [Member]	Dec. 31, 2013 Transmission and distribution facilities [Member]
Jointly Owned Utility Plant Interests [Line Items]
PacifiCorp Share			67.00%	94.00%	60.00%	80.00%	10.00%	50.00%	[1]	19.00%	[2]	25.00%	13.00%	79.00%
PacifiCorp Share															Various
Facility in Service	$ 3,446		$ 1,121	$ 394	$ 293	$ 450	$ 227	$ 173	[1]	$ 323	[2]	$ 55	$ 32	$ 37	$ 341
Accumulated Depreciation and Amortization	1,413		511	150	84	166	122	61	[1]	195	[2]	25	17	21	61
Construction Work-in-Progress	92		19	54	0	1	4	1	[1]	2	[2]	6	2	0	3
Percentage of remaining output the company has contracted to purchase								50.00%
Unallocated acquisition adjustments included in facility in service	159	159								141
Unallocated acquisition adjustments included in accumulated depreciation and amortization	$ 118	$ 113								$ 102

[1] As discussed in Note 17, PacifiCorp has contracted to purchase the remaining 50% of the output of the Hermiston generating facility.

[2] Includes unallocated acquisition adjustments of $141 million related to Facility in Service and $102 million related to Accumulated Depreciation and Amortization.