Revenue from Contract with Customer - MEC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 15,081	$ 14,837	$ 14,972
Revenues	20,952	19,844	19,787
Non-contracts with customer revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues	475	534	601
MidAmerican Energy Company and Subsidiaries [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,696	2,902	3,028
Revenues	2,720	2,925	3,049
MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,429	2,508	2,551
MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,027	1,055	1,117
MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	415	454	467
MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	818	816	780
MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail [Member] | Natural gas distribution, transportation-only services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	36	38	39
MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	133	145	148
MidAmerican Energy Company and Subsidiaries [Member] | Regulated wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	199	309	411
MidAmerican Energy Company and Subsidiaries [Member] | Electricity Transmission [Member] | Multi value transmission projects [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	60	57	55
MidAmerican Energy Company and Subsidiaries [Member] | Other customer revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	8	28	11
MidAmerican Energy Company and Subsidiaries [Member] | Non-contracts with customer revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues	24	23	21
Regulated Operation [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	13,553	13,433	13,612
Regulated Operation [Member] | Regulated retail electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	9,421	9,465	9,419
Regulated Operation [Member] | Regulated retail gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	619	686	737
Regulated Operation [Member] | Regulated wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	366	457	501
Regulated Operation [Member] | Other customer revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	110	2	2
Corporate and Other [Member] | MidAmerican Energy Company and Subsidiaries [Member]
Disaggregation of Revenue [Line Items]
Revenues	8	28	12
Corporate and Other [Member] | Nonregulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	8	28	11
Revenues	8	28	12
Corporate and Other [Member] | Nonregulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Other customer revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	8	28	11
Corporate and Other [Member] | Nonregulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Non-contracts with customer revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues	0	0	1
Electricity US Regulated | MidAmerican Energy Company and Subsidiaries [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,139	2,237	2,283
Electricity US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,117	2,216	2,265
Revenues	2,139	2,237	2,283
Electricity US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,924	1,938	1,915
Electricity US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail electric [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	685	672	696
Electricity US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail electric [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	304	322	314
Electricity US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail electric [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	804	799	758
Electricity US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail electric [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	131	145	147
Electricity US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Regulated wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	133	221	295
Electricity US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Electricity Transmission [Member] | Multi value transmission projects [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	60	57	55
Electricity US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Non-contracts with customer revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues	22	21	18
Natural Gas US Regulated | MidAmerican Energy Company and Subsidiaries [Member]
Disaggregation of Revenue [Line Items]
Revenues	573	660	754
Natural Gas US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	571	658	752
Revenues	573	660	754
Natural Gas US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	505	570	636
Natural Gas US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail gas [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	342	383	421
Natural Gas US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail gas [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	111	132	153
Natural Gas US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail gas [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	14	17	22
Natural Gas US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail gas [Member] | Natural gas distribution, transportation-only services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	36	38	39
Natural Gas US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Regulated retail gas [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2	0	1
Natural Gas US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Regulated wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	66	88	116
Natural Gas US Regulated | Regulated Operation [Member] | MidAmerican Energy Company and Subsidiaries [Member] | Non-contracts with customer revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 2	$ 2	$ 2