Employee Benefit Plans - MEC (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Pension Plan [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3	$ 4
Interest cost	23	27
Expected return on plan assets	(35)	(38)
Net amortization	9	9
Net periodic benefit cost	0	2
Pension Plan [Member] | UNITED STATES | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	2
Interest cost	6	7
Expected return on plan assets	(10)	(10)
Net periodic benefit cost	(3)	(1)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	2
Interest cost	6	6
Expected return on plan assets	(9)	(10)
Net amortization	(1)	(2)
Net periodic benefit cost	(3)	(4)
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1
Interest cost	2	2
Expected return on plan assets	(3)	(3)
Net amortization	(1)	(1)
Net periodic benefit cost	$ (1)	$ (1)