Employee Benefit Plans - MEC (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Domestic Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 7	$ 8	$ 22	$ 24
Interest cost	31	30	94	91
Expected return on plan assets	(39)	(42)	(120)	(127)
Net amortization	12	13	36	41
Net periodic benefit cost	11	9	32	29
Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2	7	8
Interest cost	7	6	23	22
Expected return on plan assets	(10)	(10)	(31)	(33)
Net amortization	(2)	(1)	(9)	(7)
Net periodic benefit cost	(3)	(3)	(10)	(10)
MidAmerican Energy Company [Member] | Domestic Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	3	8	9
Interest cost	8	8	25	24
Expected return on plan assets	(11)	(11)	(33)	(34)
Net amortization	0	0	1	1
Net periodic benefit cost	0	0	1	0
MidAmerican Energy Company [Member] | Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	2	4	5
Interest cost	2	1	7	6
Expected return on plan assets	(3)	(4)	(10)	(11)
Net amortization	(1)	0	(3)	(2)
Net periodic benefit cost	$ (1)	$ (1)	$ (2)	$ (2)