Consolidated Statements of Cash Flows - SPPC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net Income (Loss) Attributable to Parent	$ 4	$ 670
Allowance for equity funds	(26)	(34)
Changes in regulatory assets and liabilities	(9)	0
Deferred income taxes and amortization of investment tax credits	(135)	47
Other Noncash Income (Expense)	(9)	(63)
Trade receivables and other assets	(249)	(118)
Accrued property, income and other taxes, net	(453)	(364)
Accounts payable and other liabilities	19	117
Net cash flows from operating activities	1,525	1,165
Capital expenditures	(1,295)	(1,356)
Net cash flows from investing activities	(1,374)	(1,474)
Net proceeds from (repayments of) short-term debt	409	(1,109)
Other, net	(9)	(32)
Net cash flows from financing activities	(191)	1,358
Net change in cash and cash equivalents and restricted cash and cash equivalents	(39)	1,036
Cash and cash equivalents and restricted cash and cash equivalents at beginning of period	1,445	1,268
Cash and cash equivalents and restricted cash and cash equivalents at end of period	1,406	2,304
Sierra Pacific Power Company [Member]
Net Income (Loss) Attributable to Parent	28	25
Depreciation and amortization	36	34
Allowance for equity funds	(1)	(1)
Changes in regulatory assets and liabilities	(13)	(10)
Deferred income taxes and amortization of investment tax credits	4	(3)
Deferred Energy Change	(18)	14
Amortization of Deferred Charges	(3)	4
Other Noncash Income (Expense)	0	(1)
Trade receivables and other assets	8	1
Increase (Decrease) in Inventories	(3)	3
Accrued property, income and other taxes, net	(3)	4
Accounts payable and other liabilities	1	(12)
Net cash flows from operating activities	42	54
Capital expenditures	(61)	(52)
Net cash flows from investing activities	(61)	(52)
Net proceeds from (repayments of) short-term debt	10	0
Other, net	(2)	(1)
Net cash flows from financing activities	8	(1)
Net change in cash and cash equivalents and restricted cash and cash equivalents	(11)	1
Cash and cash equivalents and restricted cash and cash equivalents at beginning of period	26	32
Cash and cash equivalents and restricted cash and cash equivalents at end of period	$ 15	$ 33