Employee Benefit Plans - MEC - Unrecognized Amounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	$ 549	$ 480
Pension Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement		(1)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax	(23)	50
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax	(14)	(22)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(31)	35	$ (16)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	72	38	(1)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	6	(13)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(66)	51
Other Postretirement Benefits Plan [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	4	44	10
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(45)	23
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	5	(11)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(40)	34
Other Postretirement Benefits Plan [Member] | Regulatory Liability, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(32)	(10)	(26)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	23	14
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(1)	(2)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(22)	16
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax	4	48
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax	(14)	(20)
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(10)	28	(2)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(42)	26
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	4	4
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(38)	30
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	7	37	14
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(33)	20
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	3	3
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(30)	23
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | Receivables (Payables) With Affiliates [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(17)	(9)	(16)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(9)	6
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	1	1
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(8)	7
UNITED STATES | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax	653	747
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax	(2)	0
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	652	746	642
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	61	(151)
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	31	28
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(94)	104
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net		(2)
UNITED STATES | Pension Plan [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	661	730	665
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(38)	114
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(31)	28
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(69)	65
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net		0
UNITED STATES | Pension Plan [Member] | Regulatory Liability, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(33)	0	(43)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	33	43
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	0	0
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(33)	43
Defined Benefit Plan, Amortization of Prior Service Cost (Credit), Net		0
UNITED STATES | Pension Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Gains (Losses), Before Tax	6	40
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Net Prior Service Cost (Credit), Before Tax	(1)	1
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	5	41	(10)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(35)	52
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(1)	(2)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement		1
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(36)	51
UNITED STATES | Pension Plan [Member] | MidAmerican Energy Company [Member] | Regulatory Asset, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	19	25	24
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(5)	2
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	(1)	(2)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement		1
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(6)	1
UNITED STATES | Pension Plan [Member] | MidAmerican Energy Company [Member] | Regulatory Liability, Pension and Other Postretirement Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	(32)	0	(41)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	(32)	41
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	0	0
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	(32)	41
UNITED STATES | Pension Plan [Member] | MidAmerican Energy Company [Member] | Receivables (Payables) With Affiliates [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Before Tax	18	16	$ 7
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Defined Benefit Plan, Net Unamortized Gain (Loss) Arising During Period, Before Tax	2	9
Defined Benefit Plan, Net Amortization Recognized in Net Periodic Benefit Cost Before Tax	0	0
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Arising During Period, Before Tax	$ 2	$ 9