Jointly Owned Utility Facilities Jointly Owned Utility Facilities - MEC (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 9,651
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	4,353
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	183
MidAmerican Energy Company [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	4,126
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	1,882
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 86
MidAmerican Energy Company [Member] | Louisa Unit No 1 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	88.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 807
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	432
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 8
MidAmerican Energy Company [Member] | Quad Cities Unit Nos 1 and 2 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	25.00%	[1]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 698	[1]
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	387	[1]
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 20	[1]
MidAmerican Energy Company [Member] | Walter Scott, Jr. No. 3 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	79.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 617
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	316
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 8
MidAmerican Energy Company [Member] | Walter Scott Jr Unit No 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	60.00%	[2]
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 456	[2]
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	112	[2]
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	1	[2]
Revenue sharing credits netted against facility in service	319
Revenue sharing credits netted against accumulated depreciation	$ 81
MidAmerican Energy Company [Member] | George Neal No. 4 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	41.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 307
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	159
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 1
MidAmerican Energy Company [Member] | Ottumwa Unit No 1 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	52.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 567
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	206
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 40
MidAmerican Energy Company [Member] | George Neal Unit No 3 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	72.00%
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service	$ 425
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	183
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 7
MidAmerican Energy Company [Member] | Transmission 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	$ 249
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation	87
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 1

[1] (1)Includes amounts related to nuclear fuel.

[2] (2)Plant in service and accumulated depreciation and amortization amounts are net of credits applied under Iowa revenue sharing arrangements totaling $319 million and $81 million, respectively.