Employee Benefit Plans - Contributions and Benefit Payments (Details) £ in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2020 GBP (£)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months		$ 53
Defined Benefit Plan, Expected Future Benefit Payment, Year Two		54
Defined Benefit Plan, Expected Future Benefit Payment, Year Three		54
Defined Benefit Plan, Expected Future Benefit Payment, Year Four		54
Defined Benefit Plan, Expected Future Benefit Payment, Year Five		52
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter		238
Defined Benefit Plan, Plan Assets, Contributions by Employer		3	$ 2
Other Postretirement Benefits Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		1
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months		24
Defined Benefit Plan, Expected Future Benefit Payment, Year Two		23
Defined Benefit Plan, Expected Future Benefit Payment, Year Three		22
Defined Benefit Plan, Expected Future Benefit Payment, Year Four		22
Defined Benefit Plan, Expected Future Benefit Payment, Year Five		20
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter		90
Defined Benefit Plan, Plan Assets, Contributions by Employer	[1]	0	1
UNITED STATES | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		13
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months		236
Defined Benefit Plan, Expected Future Benefit Payment, Year Two		219
Defined Benefit Plan, Expected Future Benefit Payment, Year Three		220
Defined Benefit Plan, Expected Future Benefit Payment, Year Four		211
Defined Benefit Plan, Expected Future Benefit Payment, Year Five		206
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter		926
Defined Benefit Plan, Plan Assets, Contributions by Employer		13	12
UNITED STATES | Pension Plan [Member] | PacifiCorp [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		4
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months		115
Defined Benefit Plan, Expected Future Benefit Payment, Year Two		99
Defined Benefit Plan, Expected Future Benefit Payment, Year Three		94
Defined Benefit Plan, Expected Future Benefit Payment, Year Four		87
Defined Benefit Plan, Expected Future Benefit Payment, Year Five		82
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter		341
Defined Benefit Plan, Plan Assets, Contributions by Employer	[1]	5	4
UNITED STATES | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		14
UNITED KINGDOM | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year | £				£ 50
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months		74
Defined Benefit Plan, Expected Future Benefit Payment, Year Two		75
Defined Benefit Plan, Expected Future Benefit Payment, Year Three		77
Defined Benefit Plan, Expected Future Benefit Payment, Year Four		79
Defined Benefit Plan, Expected Future Benefit Payment, Year Five		81
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter		431
Defined Benefit Plan, Plan Assets, Contributions by Employer		$ 56	$ 56

[1] Amounts represent employer contributions to the SERP