Employee Benefit Plans - MEC (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Pension Plan [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 7	$ 3
Interest cost	20	23
Expected return on plan assets	(33)	(35)
Net amortization	6	9
Net periodic benefit cost	0	0
Pension Plan [Member] | UNITED STATES | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	1
Interest cost	6	6
Expected return on plan assets	(9)	(10)
Net periodic benefit cost	2	(3)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	1
Interest cost	5	6
Expected return on plan assets	(5)	(9)
Net amortization	(1)	(1)
Net periodic benefit cost	1	(3)
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	1
Interest cost	2	2
Expected return on plan assets	(2)	(3)
Net amortization	(1)	(1)
Net periodic benefit cost	$ 1	$ (1)