Employee Benefit Plans Employee Benefit Plans - PacifiCorp (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)
PacifiCorp [Member] | Domestic Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	3	3
Interest cost	14	13	41	40
Expected return on plan assets	(18)	(19)	(56)	(58)
Net amortization	8	10	25	31
Net periodic benefit cost	5	5	13	16
PacifiCorp [Member] | Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	0	2	2
Interest cost	3	4	11	12
Expected return on plan assets	(5)	(5)	(16)	(17)
Net amortization	(1)	(1)	(4)	(3)
Net periodic benefit cost	$ (2)	$ (2)	$ (7)	$ (6)