Jointly Owned Utility Facilities - PacifiCorp (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 9,871
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	4,653
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	4,467
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	2,032
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 123
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	$ 1,476
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	677
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 9
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	$ 484
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	193
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	121
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 2
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	$ 473
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	243
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 1
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	$ 254
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	137
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 2
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	$ 181
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	92
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 5
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	252
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	39
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	$ 43
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	23
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	$ 808
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	255
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 103