Consolidated Statements of Cash Flows - NPC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net Income (Loss) Attributable to Parent	$ 556	$ 490
Deferred income taxes and amortization of investment tax credits	224	72
Allowance for equity funds	(17)	(15)
Increase (Decrease) in Regulatory Assets and Liabilities	20	60
Other Noncash Income (Expense)	(5)	3
Increase (Decrease) in Accounts Receivable and Other Operating Assets	288	219
Accrued property, income and other taxes	(187)	(2)
Accounts payable and other liabilities	(37)	(73)
Net cash flows from operating activities	1,418	1,360
Capital expenditures	(865)	(1,027)
Acquisitions, net of cash acquired	(579)	(13)
Net cash flows from investing activities	(1,450)	(1,284)
Net cash flows from financing activities	328	(99)
Net change in cash and cash equivalents	297	(22)
Cash and cash equivalents at end of period	1,018	1,086
Cash and cash equivalents at beginning of period	721	1,108
Nevada Power Company [Member]
Net Income (Loss) Attributable to Parent	10	3
Utilities Operating Expense, Depreciation and Amortization	76	75
Deferred income taxes and amortization of investment tax credits	22	2
Allowance for equity funds	(1)	(1)
Increase (Decrease) in Regulatory Assets and Liabilities	3	7
Deferred Energy Change	(25)	23
Amortization of Deferred Charges	3	(14)
Other Noncash Income (Expense)	(2)	0
Increase (Decrease) in Accounts Receivable and Other Operating Assets	51	47
Increase (Decrease) in Inventories	7	0
Accrued property, income and other taxes	(26)	(1)
Accounts payable and other liabilities	(29)	(18)
Net cash flows from operating activities	89	123
Capital expenditures	(58)	(98)
Acquisitions, net of cash acquired	(77)	0
Net cash flows from investing activities	(135)	(98)
Repayments of Long-term Debt	(79)	(214)
Payments of Ordinary Dividends, Common Stock	(75)	0
Net cash flows from financing activities	(154)	(214)
Net change in cash and cash equivalents	(200)	(189)
Cash and cash equivalents at end of period	79	347
Cash and cash equivalents at beginning of period	$ 279	$ 536