Consolidated Statements of Cash Flows - NPC - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Net Income (Loss) Attributable to Parent	$ 1,026	$ 1,027
Deferred income taxes and amortization of investment tax credits	291	390
Allowance for equity funds	(130)	(61)
Increase (Decrease) in Regulatory Assets and Liabilities	(1)	243
Other Noncash Income (Expense)	72	(13)
Increase (Decrease) in Accounts Receivable and Other Operating Assets	252	418
Accounts payable and other liabilities	94	(48)
Net cash flows from operating activities	2,771	3,533
Payments to Acquire Property, Plant, and Equipment	2,103	2,624
Payments for (Proceeds from) Other Investing Activities	46	(43)
Net cash flows from investing activities	(2,455)	(2,645)
Net cash flows from financing activities	(642)	(373)
Net change in cash and cash equivalents	(330)	515
Cash and cash equivalents at end of period	778	1,132
Cash and cash equivalents at beginning of period	1,108	617
Other, net	(39)	(43)
Nevada Power Company [Member]
Net Income (Loss) Attributable to Parent	69	84
Other Nonrecurring (Income) Expense	0	(3)
Utilities Operating Expense, Depreciation and Amortization	151	148
Deferred income taxes and amortization of investment tax credits	25	47
Allowance for equity funds	(3)	(2)
Increase (Decrease) in Regulatory Assets and Liabilities	17	(19)
Deferred Energy Change	31	87
Amortization of Deferred Charges	(42)	(35)
Other Noncash Income (Expense)	(4)	15
Increase (Decrease) in Accounts Receivable and Other Operating Assets	70	144
Increase (Decrease) in Inventories	(2)	1
Accounts payable and other liabilities	60	40
Net cash flows from operating activities	244	257
Payments to Acquire Property, Plant, and Equipment	181	125
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	(181)	(106)
Repayments of Long-term Debt	217	252
Net cash flows from financing activities	(487)	(265)
Net change in cash and cash equivalents	(424)	(114)
Cash and cash equivalents at end of period	112	106
Cash and cash equivalents at beginning of period	536	220
Payments of Ordinary Dividends, Common Stock	$ 270	$ 13