Consolidated Statements of Cash Flows - NPC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net Income (Loss) Attributable to Parent	$ 513	$ 556
Deferred income taxes and amortization of investment tax credits	(166)	224
Allowance for equity funds	(21)	(17)
Changes in regulatory assets and liabilities	94	20
Other Noncash Income (Expense)	19	(2)
Trade receivables and other assets	250	308
Accrued property, income and other taxes	(60)	(187)
Accounts payable and other liabilities	(40)	(37)
Net cash flows from operating activities	1,479	1,438
Capital expenditures	(1,075)	(865)
Acquisitions, net of cash acquired	0	(579)
Net cash flows from investing activities	(1,223)	(1,538)
Repayments of Long-term Debt	0	(200)
Net cash flows from financing activities	336	328
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	593	229
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	1,876	1,232
Nevada Power Company [Member]
Net Income (Loss) Attributable to Parent	0	10
Utilities Operating Expense, Depreciation and Amortization	84	76
Deferred income taxes and amortization of investment tax credits	(7)	22
Allowance for equity funds	(1)	(1)
Changes in regulatory assets and liabilities	10	3
Deferred Energy Change	0	(25)
Amortization of Deferred Charges	3	3
Other Noncash Income (Expense)	9	(2)
Trade receivables and other assets	48	52
Increase (Decrease) in Inventories	1	7
Accrued property, income and other taxes	(1)	(26)
Accounts payable and other liabilities	(36)	(29)
Net cash flows from operating activities	110	90
Capital expenditures	(64)	(58)
Acquisitions, net of cash acquired	0	(77)
Net cash flows from investing activities	(64)	(135)
Repayments of Long-term Debt	(5)	(79)
Payments of Ordinary Dividends, Common Stock	0	(75)
Net cash flows from financing activities	(5)	(154)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	41	(199)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 107	$ 91