Employee Benefit Plans - MEC (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Plan [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 4	$ 7	$ 8
Interest cost	23	28	46	55
Expected return on plan assets	(35)	(39)	(70)	(77)
Net amortization	8	7	17	16
Net periodic benefit cost	0	0	0	2
Pension Plan [Member] | UNITED STATES | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	2	3
Interest cost	6	8	12	15
Expected return on plan assets	(10)	(11)	(20)	(21)
Net amortization	1	0	1	0
Net periodic benefit cost	(2)	(2)	(5)	(3)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	3	4	5
Interest cost	4	8	10	14
Expected return on plan assets	(7)	(10)	(16)	(20)
Net amortization	(3)	(1)	(4)	(3)
Net periodic benefit cost	(3)	0	(6)	(4)
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	2	2	3
Interest cost	1	3	3	5
Expected return on plan assets	(3)	(3)	(6)	(6)
Net amortization	(2)	(1)	(3)	(2)
Net periodic benefit cost	$ (3)	$ 1	$ (4)	$ 0