Consolidated Statements of Cash Flows - NPC - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Net Income (Loss) Attributable to Parent	$ 2,062	$ 1,901
Deferred income taxes and amortization of investment tax credits	546	617
Allowance for equity funds	(147)	(84)
Increase (Decrease) in Regulatory Assets and Liabilities	41	326
Other Noncash Income (Expense)	60	(41)
Increase (Decrease) in Accounts Receivable and Other Operating Assets	348	251
Accrued property, income and other taxes	713	1,608
Accounts payable and other liabilities	183	(47)
Net cash flows from operating activities	4,824	5,909
Payments to Acquire Property, Plant, and Equipment	3,521	4,251
Payments for (Proceeds from) Other Investing Activities	47	(67)
Net cash flows from investing activities	(4,117)	(4,446)
Net cash flows from financing activities	(792)	(428)
Net change in cash and cash equivalents	(90)	1,034
Cash and cash equivalents at end of period	1,018	1,651
Cash and cash equivalents at beginning of period	1,108	617
Nevada Power Company [Member]
Net Income (Loss) Attributable to Parent	257	271
Other Nonrecurring (Income) Expense	0	(3)
Utilities Operating Expense, Depreciation and Amortization	227	222
Deferred income taxes and amortization of investment tax credits	52	123
Allowance for equity funds	(3)	(3)
Increase (Decrease) in Regulatory Assets and Liabilities	139	(8)
Deferred Energy Change	(3)	133
Amortization of Deferred Charges	(87)	(40)
Other Noncash Income (Expense)	(3)	3
Increase (Decrease) in Accounts Receivable and Other Operating Assets	96	204
Increase (Decrease) in Inventories	(7)	(10)
Accrued property, income and other taxes	98	36
Accounts payable and other liabilities	7	8
Net cash flows from operating activities	601	622
Payments to Acquire Property, Plant, and Equipment	249	214
Proceeds from Sale of Other Property, Plant, and Equipment	0	9
Payments for (Proceeds from) Other Investing Activities	0	(10)
Net cash flows from investing activities	(249)	(195)
Repayments of Long-term Debt	221	260
Payments of Ordinary Dividends, Common Stock	365	13
Net cash flows from financing activities	(586)	(273)
Net change in cash and cash equivalents	(234)	154
Cash and cash equivalents at end of period	302	374
Cash and cash equivalents at beginning of period	$ 536	$ 220