Employee Benefit Plans Employee Benefit Plans - PacifiCorp (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)
PacifiCorp [Member] | Domestic Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	1	0	2
Interest cost	13	13	25	27
Expected return on plan assets	(18)	(19)	(36)	(38)
Net amortization	3	9	7	17
Net periodic benefit cost	(2)	4	(4)	8
PacifiCorp [Member] | Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	1	1
Interest cost	4	4	7	8
Expected return on plan assets	(5)	(5)	(11)	(11)
Net amortization	(2)	(2)	(3)	(3)
Net periodic benefit cost	$ (3)	$ (3)	$ (6)	$ (5)