Document And Entity Information (USD $)	6 Months Ended
	Jun. 30, 2011	Aug. 04, 2011	Jun. 30, 2010
Entity Information [Line Items]
Entity Registrant Name	NV Energy, Inc.
Entity Central Index Key	0000741508
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float	$ 3,622,247,595
Entity Common Stock, Shares Outstanding		235,990,761
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2011
Nevada Power Company [Member]
Entity Information [Line Items]
Entity Registrant Name	NEVADA POWER CO
Entity Central Index Key	0000071180
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float			0
Entity Common Stock, Shares Outstanding		1,000
Sierra Pacific Power Company [Member]
Entity Information [Line Items]
Entity Registrant Name	SIERRA PACIFIC POWER CO
Entity Central Index Key	0000090144
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float			$ 0
Entity Common Stock, Shares Outstanding		1,000