Employee Benefit Plans Employee Benefit Plans - PacifiCorp (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2	$ 2
Interest cost	6	6
Expected return on plan assets	(10)	(10)
Net amortization	(2)	(3)
Net periodic benefit cost	(4)	(5)
PacifiCorp [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0
Interest cost	3	3
Expected return on plan assets	(5)	(5)
Net amortization	0	(1)
Net periodic benefit cost	(2)	(3)
Domestic Plan [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	5
Interest cost	27	26
Expected return on plan assets	(38)	(41)
Net amortization	9	8
Net periodic benefit cost	2	(2)
Domestic Plan [Member] | PacifiCorp [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0
Interest cost	11	11
Expected return on plan assets	(17)	(18)
Net amortization	3	3
Net periodic benefit cost	$ (3)	$ (4)