Employee Benefit Plans - MEC (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Domestic Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 7	$ 8	$ 15	$ 16
Interest cost	32	31	63	61
Expected return on plan assets	(41)	(43)	(81)	(85)
Net amortization	13	15	24	28
Net periodic benefit cost	11	11	21	20
Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2	5	6
Interest cost	8	9	16	16
Expected return on plan assets	(10)	(11)	(21)	(23)
Net amortization	(4)	(3)	(7)	(6)
Net periodic benefit cost	(4)	(3)	(7)	(7)
MidAmerican Energy Company [Member] | Domestic Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	3	5	6
Interest cost	9	8	17	16
Expected return on plan assets	(11)	(12)	(22)	(23)
Net amortization	1	1	1	1
Net periodic benefit cost	1	0	1	0
MidAmerican Energy Company [Member] | Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	1	3	3
Interest cost	3	3	5	5
Expected return on plan assets	(4)	(3)	(7)	(7)
Net amortization	(1)	(1)	(2)	(2)
Net periodic benefit cost	$ 0	$ 0	$ (1)	$ (1)