Employee Benefit Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement			$ 1
Pension Plan [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Regulatory Deferrals, Before Tax	$ (2)	$ (1)
Defined Benefit Plan, Service Cost	17	16	21
Defined Benefit Plan, Interest Cost	93	111	105
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(140)	(154)	(164)
Defined Benefit Plan, Accumulated Benefit Obligation, (Increase) Decrease for Settlement and Curtailment	0	0	21
Defined Benefit Plan Net Amortization	32	31	28
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	2	4	11
Pension Plan [Member] | UNITED STATES | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	8	6	9
Defined Benefit Plan, Interest Cost	25	30	28
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(40)	(41)	(44)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement			(1)
Defined Benefit Plan Net Amortization	1	1	2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(6)	(4)	(6)
Pension Plan [Member] | UNITED STATES | MidAmerican Energy Company [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(13)	(8)	(9)
Pension Plan [Member] | UNITED KINGDOM
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	16	16	19
Defined Benefit Plan, Interest Cost	40	49	56
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(101)	(100)	(101)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	17	26	44
Defined Benefit Plan Net Amortization	43	46	45
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	15	37	63
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Regulatory Deferrals, Before Tax	(3)	(6)
Defined Benefit Plan, Service Cost	7	8	9
Defined Benefit Plan, Interest Cost	21	27	24
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(34)	(40)	(41)
Defined Benefit Plan, Accumulated Benefit Obligation, (Increase) Decrease for Settlement and Curtailment	0	0	0
Defined Benefit Plan Net Amortization	4	6	13
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(10)	(11)	(21)
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	4	5	5
Defined Benefit Plan, Interest Cost	7	10	8
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(14)	(13)	(13)
Defined Benefit Plan Net Amortization	(5)	(3)	(4)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(8)	(1)	(4)
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (5)	$ 1	$ (2)