Employee Benefit Plans - MEC - 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
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
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 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)
UNITED STATES | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
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 Net Amortization	32	31	28
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	2	4	11
UNITED STATES | Pension Plan [Member] | 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)
UNITED STATES | Pension Plan [Member] | 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)