Employee Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	May. 31, 2015
Domestic Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 8	$ 11	$ 24	$ 28
Interest cost	30	32	91	98
Expected return on plan assets	(42)	(41)	(127)	(123)
Net amortization	13	8	41	28
Net periodic benefit cost	9	10	29	31
Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	4	8	11
Interest cost	6	11	22	34
Expected return on plan assets	(10)	(14)	(33)	(39)
Net amortization	(1)	(1)	(7)	(3)
Net periodic benefit cost	(3)	0	(10)	3
UK Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	6	6	18	18
Interest cost	20	24	60	72
Expected return on plan assets	(29)	(31)	(87)	(94)
Net amortization	17	12	49	39
Net periodic benefit cost	$ 14	$ 11	$ 40	$ 35
PacifiCorp [Member] | Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, amount to be transferred					$ 150
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Regulatory Deferrals, Before Tax					$ 9