Employee Benefit Plans - Asset Allocations (Details)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Year that Rate Reaches Ultimate Trend Rate	2025
UK Pension Plans [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	50.00%	[1]
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	55.00%	[1]
UK Pension Plans [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	35.00%	[1]
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	40.00%	[1]
UK Pension Plans [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	5.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	15.00%
PacifiCorp [Member] | Domestic Pension Plans [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	33.00%	[2]
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	37.00%	[2]
PacifiCorp [Member] | Domestic Pension Plans [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	53.00%	[2]
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	57.00%	[2]
PacifiCorp [Member] | Domestic Pension Plans [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	8.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	12.00%
PacifiCorp [Member] | Domestic Pension Plans [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	0.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	1.00%
PacifiCorp [Member] | Domestic Other Postretirement Plans [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	33.00%	[2]
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	37.00%	[2]
PacifiCorp [Member] | Domestic Other Postretirement Plans [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	61.00%	[2]
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	65.00%	[2]
PacifiCorp [Member] | Domestic Other Postretirement Plans [Member] | Limited Partnership Interests [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	1.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	3.00%
PacifiCorp [Member] | Domestic Other Postretirement Plans [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	0.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	1.00%
MidAmerican Energy Company [Member] | Domestic Pension Plans [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	20.00%	[2]
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	40.00%	[2]
MidAmerican Energy Company [Member] | Domestic Pension Plans [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	60.00%	[2]
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	80.00%	[2]
MidAmerican Energy Company [Member] | Domestic Pension Plans [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	2.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	8.00%
MidAmerican Energy Company [Member] | Domestic Pension Plans [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	0.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	5.00%
MidAmerican Energy Company [Member] | Domestic Other Postretirement Plans [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	25.00%	[2]
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	45.00%	[2]
MidAmerican Energy Company [Member] | Domestic Other Postretirement Plans [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	50.00%	[2]
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	80.00%	[2]
MidAmerican Energy Company [Member] | Domestic Other Postretirement Plans [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	0.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	0.00%
MidAmerican Energy Company [Member] | Domestic Other Postretirement Plans [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	0.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	5.00%
NV Energy [Member] | Domestic Pension Plans [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	53.00%	[2]
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	77.00%	[2]
NV Energy [Member] | Domestic Pension Plans [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	23.00%	[2]
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum	47.00%	[2]
NV Energy [Member] | Domestic Other Postretirement Plans [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	40.00%	[2]
NV Energy [Member] | Domestic Other Postretirement Plans [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum	60.00%	[2]
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Year that Rate Reaches Ultimate Trend Rate			2019
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Year that Rate Reaches Ultimate Trend Rate			2029

[1] For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds have been allocated based on the underlying investments in debt and equity securities.

[2] For purposes of target allocation percentages and consistent with the plans' investment policy, investment funds are allocated based on the underlying investments in debt and equity securities.