Employee Benefit Plans - MEC (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Pension Plan [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 5	$ 12	$ 15
Interest cost	27	26	82	78
Expected return on plan assets	(38)	(41)	(115)	(123)
Net amortization	8	8	24	23
Net periodic benefit cost	1	(2)	3	(7)
Pension Plan [Member] | UNITED STATES | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2	5	6
Interest cost	7	7	22	21
Expected return on plan assets	(10)	(11)	(31)	(33)
Net amortization	0	1	0	2
Net periodic benefit cost	(1)	(1)	(4)	(4)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	6	6
Interest cost	6	7	20	19
Expected return on plan assets	(10)	(9)	(30)	(31)
Net amortization	0	(3)	(3)	(9)
Net periodic benefit cost	(3)	(4)	(7)	(15)
Other Postretirement Benefits Plan [Member] | MidAmerican Energy Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	4	4
Interest cost	2	2	7	6
Expected return on plan assets	(3)	(3)	(9)	(10)
Net amortization	(1)	(1)	(3)	(3)
Net periodic benefit cost	$ (1)	$ (1)	$ (1)	$ (3)