Employee Benefit Plans - PacifiCorp - Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 9	$ 9	$ 11
Defined Benefit Plan, Interest Cost	29	31	31
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(40)	(41)	(45)
Defined Benefit Plan Net Amortization	(14)	(12)	(11)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(16)	(13)	(14)
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	2	2	3
Defined Benefit Plan, Interest Cost	14	15	16
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(21)	(21)	(23)
Defined Benefit Plan Net Amortization	(6)	(5)	(4)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(11)	(9)	(8)
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	24	29	33
Defined Benefit Plan, Interest Cost	116	126	121
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(160)	(160)	(169)
Defined Benefit Plan Net Amortization	25	46	53
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	5	41	38
Domestic Plan [Member] | Pension Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	0	4	4
Defined Benefit Plan, Interest Cost	49	54	53
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(72)	(75)	(77)
Defined Benefit Plan Net Amortization	14	34	42
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (9)	$ 17	$ 22