Jointly Owned Utility Facilities - PacifiCorp (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 10,443
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	5,167
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	172
PacifiCorp [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	4,535
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	2,171
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 126
PacifiCorp [Member] | Jim Bridger Unit Nos 1 thru 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	67.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 1,485
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	714
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 15
PacifiCorp [Member] | Hunter Unit No 1 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	94.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 486
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	203
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 1
PacifiCorp [Member] | Hunter No. 2 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	60.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 305
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	127
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0
PacifiCorp [Member] | Wyodak [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	80.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 476
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	254
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 2
PacifiCorp [Member] | Colstrip Unit Nos 3 and 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	10.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 255
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	145
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 6
PacifiCorp [Member] | Hermiston [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	50.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 184
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	93
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 2
PacifiCorp [Member] | Craig Units Nos 1 and 2 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	19.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 368
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	305
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0
PacifiCorp [Member] | Hayden Unit No 1 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	25.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 75
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	42
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0
PacifiCorp [Member] | Hayden No. 2 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	13.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 44
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	25
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0
PacifiCorp [Member] | Transmission and distribution facilities
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Percentage Share	Various
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 857
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	263
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 100