SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2012

Accounting Policies [Abstract]

Gross Utility Property and CWIP

		2012						2011
		NVE		NPC		SPPC		NVE		NPC		SPPC
Electric Generation assets		$	4,766	$	3,706	$	1,060	$	4,791	$	3,724	$	1,067
Electric Transmission assets			1,867		1,189		678		1,853		1,183		670
Electric Distribution assets			4,142		2,886		1,256		4,108		2,874		1,234
Electric General, Intangible plant			685		583		102		659		564		95
Electric CWIP			683		568		115		443		353		90
Natural Gas Distribution assets			341		-		341		312		-		312
Natural Gas General, Intangible plant			13		-		13		3		-		3
Natural Gas CWIP			6		-		6		14		-		14
Common General, Intangible Plant			218		-		218		197		-		197
Common CWIP			18		-		18		31		-		31
	Total Utility Property, Gross	$	12,739	$	8,932	$	3,807	$	12,411	$	8,698	$	3,713

Average Estimated Use Life for Major Class of Utility Property, Plant, and Equipment

	Estimated Useful Lives
	NPC	SPPC
Electric Generation	25 to 125 years	25 to 125 years
Electric Transmission	45 to 65 years	50 to 70 years
Electric Distribution	20 to 65 years	30 to 65 years
Gas Distribution	N/A	40 to 70 years
General Plant	5 to 65 years	5 to 65 years

Schedule of Change in Asset Retirement Obligation [Table Text Block]

		NVE				NPC				SPPC
		2012		2011		2012		2011		2012		2011
ARO balance at January 1	$	70,984	$	55,204	$	61,020	$	47,128	$	9,964	$	8,076
Liabilities incurred in current period		-		3,282		-		3,282		-		-
Liabilities settled in current period		-		(6,996)		-		(6,996)		-		-
Accretion expense		4,064		3,866		3,453		3,348		611		518
Revision in estimated cash flows		145		16,391		(4,002)		15,021		4,147		1,370
Gain/Loss on settlement		-		(763)		0		(763)		-		-
ARO balance at December 31	$	75,193	$	70,984	$	60,471	$	61,020	$	14,722	$	9,964