Employee Benefit Plans - MEC (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Pension Plan [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 5	$ 8	$ 10
Interest cost	28	26	55	52
Expected return on plan assets	(39)	(41)	(77)	(82)
Net amortization	7	7	16	15
Net periodic benefit cost	0	(3)	2	(5)
Pension Plan [Member] | Domestic Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	2	3	4
Interest cost	8	7	15	14
Expected return on plan assets	(11)	(11)	(21)	(22)
Net amortization	0	0	0	1
Net periodic benefit cost	(2)	(2)	(3)	(3)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	3	5	5
Interest cost	8	6	14	12
Expected return on plan assets	(10)	(12)	(20)	(22)
Net amortization	(1)	(3)	(3)	(6)
Net periodic benefit cost	0	(6)	(4)	(11)
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2	3	3
Interest cost	3	2	5	4
Expected return on plan assets	(3)	(4)	(6)	(7)
Net amortization	(1)	(1)	(2)	(2)
Net periodic benefit cost	$ 1	$ (1)	$ 0	$ (2)