Employee Benefit Plans - MEC (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Domestic Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 6	$ 7	$ 12	$ 15
Interest cost	29	32	58	63
Expected return on plan assets	(40)	(41)	(80)	(81)
Net amortization	8	13	15	24
Net periodic benefit cost	3	11	5	21
Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2	4	5
Interest cost	8	8	14	16
Expected return on plan assets	(11)	(10)	(21)	(21)
Net amortization	(4)	(4)	(7)	(7)
Net periodic benefit cost	(5)	(4)	(10)	(7)
MidAmerican Energy Company [Member] | Domestic Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	2	5	5
Interest cost	7	9	15	17
Expected return on plan assets	(11)	(11)	(22)	(22)
Net amortization	1	1	1	1
Net periodic benefit cost	0	1	(1)	1
MidAmerican Energy Company [Member] | Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	2	2	3
Interest cost	2	3	4	5
Expected return on plan assets	(4)	(4)	(7)	(7)
Net amortization	(1)	(1)	(2)	(2)
Net periodic benefit cost	$ (2)	$ 0	$ (3)	$ (1)