Employee Benefit Plans - MEC (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Pension Plan [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 5
Interest cost	27	26
Expected return on plan assets	(38)	(41)
Net amortization	9	8
Net periodic benefit cost	2	(2)
Pension Plan [Member] | Domestic Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2
Interest cost	7	7
Expected return on plan assets	(10)	(11)
Net amortization	0	1
Net periodic benefit cost	(1)	(1)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2
Interest cost	6	6
Expected return on plan assets	(10)	(10)
Net amortization	(2)	(3)
Net periodic benefit cost	(4)	(5)
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)