Name:	nve_AmountOfOverCollectionAgainstDeferredBtgrDebitBalance
Namespace Prefix:	nve_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Deferred base tariff general rate balance that was a result of a prior period recognition of deferred rate increase asset.

No definition available.

Name:	nve_DeferredBaseTariffGeneralRateBalance
Namespace Prefix:	nve_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of deferred costs requested to be refunded.

No definition available.

Name:	nve_DeferredCostsRefundRequested
Namespace Prefix:	nve_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	nve_GeneratingStationAbstract
Namespace Prefix:	nve_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Mohave costs including decommissioning costs approved in NPC 2011 GRC.

No definition available.

Name:	nve_MohaveCostsApproved
Namespace Prefix:	nve_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Decommissioning costs accumulated in other regulatory assets as incurred.

No definition available.

Name:	nve_MohaveDecommissioningCosts
Namespace Prefix:	nve_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Mohave regulatory assets approved by the PUCN

No definition available.

Name:	nve_MohaveRegulatoryAsset
Namespace Prefix:	nve_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of requested rate increase (decrease) in the Deferred Energy Accounting Adjustment application filed with the applicable Utilities Commission.

No definition available.

Name:	nve_RequestedDeaaRateIncreaseDecrease
Namespace Prefix:	nve_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The percentage rate increase (decrease) in the Deferred Energy Accounting Adjustment application filed with the applicable Utilities Commission.

No definition available.

Name:	nve_RequestedDeaaRateIncreaseDecreasePercentage
Namespace Prefix:	nve_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	nve_SettledRegulatoryActionsAbstract
Namespace Prefix:	nve_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The proportionate share of interest (percent) in a jointly owned utility plant.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 360

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 10.C)

-URI http://asc.fasb.org/extlink&oid=6500719&loc=d3e659983-123033

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 10

-Section C