CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 15,218	$ 35,225
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	172,708	165,644
Deferred taxes and deferred investment tax credit	7,889	18,160
AFUDC-equity	(11,164)	(13,091)
Deferred energy	3,447	92,909
Gain On Sale Of Assets	0	(7,575)
Amortization of other regulatory assets	78,080	42,831
Deferred rate increase	32,239	(4,103)
Other, net	7,022	11,619
Changes in certain assets and liabilities:
Accounts receivable	(41,535)	(22,235)
Materials, supplies and fuel	(14,541)	4,101
Other current assets	4,961	5,469
Accounts payable	34,980	8,749
Accrued retirement benefits	6,755	(9,306)
Other current liabilities	(13,230)	(1,790)
Risk management assets and liabilities	1,468	5,067
Other deferred assets	(2,884)	(2,462)
Other regulatory assets	(61,796)	(23,329)
Other deferred liabilities	(17,098)	(4,999)
Net Cash from Operating Activities	202,519	300,884
CASH FLOWS FROM (USED BY) INVESTING ACTIVITIES:
Additions to utility plant (excluding AFUDC-equity)	(310,207)	(368,882)
Proceeds from sale of asset	131,789	18,225
Customer advances for construction	(3,789)	(5,380)
Contributions in aid of construction	47,213	35,466
Investments and other property - net	407	(225)
Net Cash used by Investing Activities	(134,587)	(320,796)
CASH FLOWS FROM (USED BY) FINANCING ACTIVITIES:
Proceeds from issuance of long-term debt	387,230	414,279
Retirement of long-term debt	(367,468)	(274,821)
Settlement of interest rate lock	(14,944)	0
Sale of Common Stock	8,384	3,246
Dividends paid	(56,587)	(51,693)
Net Cash from (used by) Financing Activities	(43,385)	91,011
Net Increase in Cash and Cash Equivalents	24,547	71,099
Beginning Balance in Cash and Cash Equivalents	86,189	62,706
Ending Balance in Cash and Cash Equivalents	110,736	133,805
Cash paid during period for:
Interest	156,656	163,649
Income taxes	1	14
Significant non-cash transactions:
Accrued construction expenses as of June 30,	115,412	80,453
Capital lease obligations incurred		15,336
Nevada Power Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	7,043	17,458
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	119,586	112,755
Deferred taxes and deferred investment tax credit	4,253	9,137
AFUDC-equity	(9,953)	(11,760)
Deferred energy	18,088	72,096
Amortization of other regulatory assets	38,789	29,000
Deferred rate increase	32,239	(4,103)
Other, net	514	5,289
Changes in certain assets and liabilities:
Accounts receivable	(62,992)	(59,089)
Materials, supplies and fuel	(153)	3,871
Other current assets	2,595	(417)
Accounts payable	47,878	10,510
Accrued retirement benefits	2,657	(8,963)
Other current liabilities	(7,412)	345
Risk management assets and liabilities	960	3,506
Other deferred assets	(2,405)	(1,364)
Other regulatory assets	(43,700)	(13,964)
Other deferred liabilities	(15,713)	(1,980)
Net Cash from Operating Activities	132,274	162,327
CASH FLOWS FROM (USED BY) INVESTING ACTIVITIES:
Additions to utility plant (excluding AFUDC-equity)	(252,654)	(295,827)
Proceeds from sale of asset	0	3,254
Customer advances for construction	(1,660)	(3,312)
Contributions in aid of construction	38,229	33,568
Investments and other property - net	391	(196)
Net Cash used by Investing Activities	(215,694)	(262,513)
CASH FLOWS FROM (USED BY) FINANCING ACTIVITIES:
Proceeds from issuance of long-term debt	387,329	391,266
Retirement of long-term debt	(351,713)	(233,765)
Settlement of interest rate lock	(14,944)	0
Additional investment by parent company	54,000	0
Dividends paid	(25,000)	(53,000)
Net Cash from (used by) Financing Activities	49,672	104,501
Net Increase in Cash and Cash Equivalents	(33,748)	4,315
Beginning Balance in Cash and Cash Equivalents	60,077	42,609
Ending Balance in Cash and Cash Equivalents	26,329	46,924
Cash paid during period for:
Interest	110,916	111,657
Income taxes	1	2
Significant non-cash transactions:
Accrued construction expenses as of June 30,	97,905	72,770
Capital lease obligations incurred		15,336
Sierra Pacific Power Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	20,088	28,435
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	53,122	52,889
Deferred taxes and deferred investment tax credit	9,840	6,440
AFUDC-equity	(1,211)	(1,331)
Deferred energy	(14,641)	20,813
Gain On Sale Of Assets	0	(7,575)
Amortization of other regulatory assets	39,242	13,716
Other, net	6,456	5,493
Changes in certain assets and liabilities:
Accounts receivable	21,518	36,853
Materials, supplies and fuel	(14,388)	216
Other current assets	4,304	6,181
Accounts payable	2,264	9,775
Accrued retirement benefits	3,796	(1,287)
Other current liabilities	(4,666)	(1,396)
Risk management assets and liabilities	508	1,561
Other deferred assets	(479)	(1,098)
Other regulatory assets	(18,096)	(9,365)
Other deferred liabilities	(2,468)	(2,265)
Net Cash from Operating Activities	105,189	158,055
CASH FLOWS FROM (USED BY) INVESTING ACTIVITIES:
Additions to utility plant (excluding AFUDC-equity)	(57,553)	(77,185)
Proceeds from sale of asset	131,789	14,971
Customer advances for construction	(2,129)	(2,068)
Contributions in aid of construction	8,984	1,898
Investments and other property - net	16	(119)
Net Cash used by Investing Activities	81,107	(62,503)
CASH FLOWS FROM (USED BY) FINANCING ACTIVITIES:
Proceeds from issuance of long-term debt	0	23,013
Retirement of long-term debt	(15,755)	(40,958)
Dividends paid	(104,000)	(25,000)
Net Cash from (used by) Financing Activities	(119,755)	(42,945)
Net Increase in Cash and Cash Equivalents	66,541	52,607
Beginning Balance in Cash and Cash Equivalents	9,552	14,359
Ending Balance in Cash and Cash Equivalents	76,093	66,966
Cash paid during period for:
Interest	29,817	33,124
Income taxes		12
Significant non-cash transactions:
Accrued construction expenses as of June 30,	$ 17,507	$ 7,683