Southwestern Public Service 10-Q 27 Apr 23 2023 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2023	Apr. 27, 2023
Cover [Abstract]
Entity Registrant Name	SOUTHWESTERN PUBLIC SERVICE CO
Entity Central Index Key	0000092521
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Amendment Flag	false
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity Tax Identification Number	75-0575400
Entity Incorporation, State or Country Code	NM
Entity Address, Address Line One	790 South Buchanan Street
Entity Address, City or Town	Amarillo
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	79101
City Area Code	(303)
Local Phone Number	571-7511
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		100
Entity File Number	001-03789

STATEMENTS OF INCOME (UNAUDITED

STATEMENTS OF INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating revenues
Operating revenues	$ 508	$ 477
Operating expenses
Electric fuel and purchased power	245	237
Operating and maintenance expenses	80	72
Demand side management expenses	6	5
Depreciation and amortization	91	78
Taxes (other than income taxes)	25	25
Total operating expenses	447	417
Operating income	61	60
Allowance for funds used during construction — equity	1	0
Interest charges and financing costs
Interest charges — includes other financing costs of $1	34	29
Allowance for funds used during construction — debt	(1)	0
Total interest charges and financing costs	33	29
Income before income taxes	29	31
Income tax benefit	(25)	(21)
Net income	$ 54	$ 52

STATEMENTS OF INCOME (UNAUDIT_2

STATEMENTS OF INCOME (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Interest charges and financing costs
Debt Related Commitment Fees and Debt Issuance Costs	$ 1	$ 1

STATEMENTS OF CASH FLOWS (UNAUD

STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating activities
Net income	$ 54	$ 52
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	92	79
Deferred income taxes	(40)	(2)
Allowance for equity funds used during construction	(1)	0
Provision for bad debts	2	2
Changes in operating assets and liabilities:
Accounts receivable	23	(26)
Accrued unbilled revenues	3	0
Inventories	(14)	(6)
Prepayments and other	4	(8)
Accounts payable	(30)	0
Net regulatory assets and liabilities	108	3
Other current liabilities	(3)	(3)
Pension and other employee benefit obligations	(1)	1
Other, net	(3)	(3)
Net cash provided by operating activities	188	89
Investing activities
Utility capital/construction expenditures	(170)	(123)
Net cash used in investing activities	(170)	(123)
Financing activities
Repayments of short-term borrowings, net	44	75
Borrowings under utility money pool arrangement	5	202
Repayments under utility money pool arrangement	0	(193)
Capital contributions from parent	0	8
Dividends paid to parent	(66)	(58)
Net cash (used in) provided by financing activities	(17)	34
Net change in cash, cash equivalents and restricted cash	1	0
Cash, cash equivalents and restricted cash at beginning of period	2	1
Cash, cash equivalents and restricted cash at end of period	3	1
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(22)	(21)
Cash (paid) received for income taxes, net	(11)	3
Supplemental disclosure of non-cash investing and financing transactions:
Accrued property, plant and equipment additions	46	38
Inventory transfers to property, plant and equipment	9	4
Allowance for equity funds used during construction	1	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 3	$ 1

BALANCE SHEETS (UNAUDITED)

BALANCE SHEETS (UNAUDITED) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents	$ 3	$ 2
Accounts receivable, net	140	167
Accounts receivable from affiliates	15	15
Accrued unbilled revenues	143	140
Inventories	66	61
Regulatory assets	143	217
Derivative instruments	26	122
Prepaid taxes	4	5
Prepayments and other	65	68
Total current assets	605	797
Property, plant and equipment, net	8,210	8,129
Other assets
Regulatory assets	344	359
Derivative instruments	2	3
Operating lease right-of-use assets	426	434
Other	28	26
Total other assets	800	822
Total assets	9,615	9,748
Current liabilities
Short-term debt	78	34
Borrowings under utility money pool arrangement	5	0
Accounts payable	170	209
Accounts payable to affiliates	18	23
Regulatory liabilities	67	148
Taxes accrued	47	61
Accrued interest	42	31
Dividends payable to parent	61	61
Derivative instruments	4	4
Operating lease liabilities	31	31
Other	58	58
Total current liabilities	581	660
Deferred credits and other liabilities
Deferred income taxes	702	739
Regulatory liabilities	720	715
Asset retirement obligations	148	147
Derivative instruments	1	2
Pension and employee benefit obligations	11	12
Operating lease liabilities	395	403
Other	8	9
Total deferred credits and other liabilities	1,985	2,027
Capitalization
Long-term debt	3,211	3,211
Common stock — 200 shares authorized of $1.00 par value; 100 shares outstanding at March 31, 2023 and Dec. 31, 2022, respectively	0	0
Additional paid in capital	3,311	3,311
Retained earnings	528	540
Accumulated other comprehensive loss	(1)	(1)
Total common stockholder's equity	3,838	3,850
Total liabilities and equity	$ 9,615	$ 9,748

BALANCE SHEETS (UNAUDITED) (Par

BALANCE SHEETS (UNAUDITED) (Parenthetical) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Common Stock, Shares Authorized	200	200
Common Stock, Par or Stated Value Per Share	$ 1	$ 1
Common Stock, Shares, Outstanding	100	100

CONSOLIDATED STATEMENTS OF COMM

CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Millions	Total	Common Stock	Additional Paid In Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2021		100
Beginning balance at Dec. 31, 2021	$ 3,603	$ 0	$ 3,091	$ 513	$ (1)
Increase (Decrease) in Stockholders' Equity
Net income	52			52
Dividends declared to parent	(53)			(53)
Contributions of capital by parent	8		8
Ending balance (in shares) at Mar. 31, 2022		100
Ending balance at Mar. 31, 2022	$ 3,610	$ 0	3,099	512	(1)
Beginning balance (in shares) at Dec. 31, 2022	100	100
Beginning balance at Dec. 31, 2022	$ 3,850	$ 0	3,311	540	(1)
Increase (Decrease) in Stockholders' Equity
Net income	54			54
Dividends declared to parent	$ (66)			(66)
Ending balance (in shares) at Mar. 31, 2023	100	100
Ending balance at Mar. 31, 2023	$ 3,838	$ 0	$ 3,311	$ 528	$ (1)

Legal

Legal $ in Millions	Mar. 31, 2023 USD ($)
Settled Litigation
Loss Contingencies [Line Items]
Loss Contingency Accrual	$ 50

Management's Opinion

Management's Opinion	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Management's Opinion	In the opinion of management, the accompanying unaudited financial statements contain all adjustments necessary to present fairly, in accordance with GAAP, the financial position of SPS as of March 31, 2023 and Dec. 31, 2022; the results of SPS’ operations, including the components of net income and changes in stockholder’s equity for the three months ended March 31, 2023 and 2022; and SPS’ cash flows for the three months ended March 31, 2023 and 2022. All adjustments are of a normal, recurring nature, except as otherwise disclosed. Management has also evaluated the impact of events occurring after March 31, 2023 up to the date of issuance of these financial statements. These statements contain all necessary adjustments and disclosures resulting from that evaluation. The Dec. 31, 2022 balance sheet information has been derived from the audited 2022 financial statements included in the SPS Annual Report on Form 10-K for the year ended Dec. 31, 2022. Notes to the financial statements have been prepared pursuant to the rules and regulations of the SEC for Quarterly Reports on Form 10-Q. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP on an annual basis have been condensed or omitted pursuant to such rules and regulations. For further information, refer to the financial statements and notes thereto included in the SPS Annual Report on Form 10-K for the year ended Dec. 31, 2022, filed with the SEC on Feb. 23, 2022. Due to the seasonality of SPS’ electric sales, interim results are not necessarily an appropriate base from which to project annual results.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	The significant accounting policies set forth in Note 1 to the financial statements in the SPS Annual Report on Form 10-K for the year ended Dec. 31, 2022 appropriately represent, in all material respects, the current status of accounting policies and are incorporated herein by reference.

Accounting Pronouncements

Accounting Pronouncements	3 Months Ended
	Mar. 31, 2023
Accounting Standards Update and Change in Accounting Principle [Abstract]
Accounting Pronouncements	As of March 31, 2023, there was no material impact from the recent adoption of new accounting pronouncements, nor expected material impact from recently issued accounting pronouncements yet to be adopted, on SPS’ financial statements.

Selected Balance Sheet Data

Selected Balance Sheet Data	3 Months Ended
	Mar. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Selected Balance Sheet Data	(Millions of Dollars) March 31, 2023 Dec. 31, 2022 Accounts receivable, net Accounts receivable $ 153 $ 180 Less allowance for bad debts (13) (13) Accounts receivable, net $ 140 $ 167 (Millions of Dollars) March 31, 2023 Dec. 31, 2022 Inventories Materials and supplies $ 47 $ 42 Fuel 19 19 Total inventories $ 66 $ 61 (Millions of Dollars) March 31, 2023 Dec. 31, 2022 Property, plant and equipment, net Electric plant $ 10,254 $ 10,182 Plant to be retired (a) 260 266 CWIP 239 167 Total property, plant and equipment 10,753 10,615 Less accumulated depreciation (2,543) (2,486) Property, plant and equipment, net $ 8,210 $ 8,129

Borrowings and Other Financing

Borrowings and Other Financing Instruments	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Borrowings and Other Financing Instruments	Short-Term Borrowings SPS meets its short-term liquidity requirements primarily through the issuance of commercial paper and borrowings under its credit facility and the money pool. Money Pool — Xcel Energy and its utility subsidiaries have established a money pool arrangement that allows for short-term investments in and borrowings between the utility subsidiaries. Xcel Energy may make investments in the utility subsidiaries at market-based interest rates; however, the money pool arrangement does not allow the utility subsidiaries to make investments in Xcel Energy. Money pool borrowings: (Amounts in Millions, Except Interest Rates) Three Months Ended March 31, 2023 Year Ended Dec. 31, 2022 Borrowing limit $ 100 $ 100 Amount outstanding at period end 5 — Average amount outstanding — 35 Maximum amount outstanding 5 100 Weighted average interest rate, computed on a daily basis 4.59 % 0.44 % Weighted average interest rate at period end 4.59 N/A Commercial Paper — Commercial paper outstanding: (Amounts in Millions, Except Interest Rates) Three Months Ended March 31, 2023 Year Ended Dec. 31, 2022 Borrowing limit $ 500 $ 500 Amount outstanding at period end 78 34 Average amount outstanding 88 100 Maximum amount outstanding 118 324 Weighted average interest rate, computed on a daily basis 4.86 % 0.79 % Weighted average interest rate at period end 5.58 4.55 Letters of Credit — SPS uses letters of credit, generally with terms of one year, to provide financial guarantees for certain obligations. At both March 31, 2023 and Dec. 31, 2022, there w ere $2 million of l etters of credit outstanding under the credit facility. Amounts approximate their fair value and are subject to fees. Revolving Credit Facility — In order to issue its commercial paper, SPS must have a revolving credit facility equal or greater than the commercial paper borrowing limit and cannot issue commercial paper exceeding available capacity under this credit facility. The credit facility provides short-term financing in the form of notes payable to banks, letters of credit and back-up support for commercial paper borrowings. SPS has the right to request an extension of the revolving credit facility termination date for two additional one-year periods. All extension requests are subject to majority bank group approval. As of March 31, 2023, SPS had the following committed revolving credit facility available (in millions of dollars): Credit Facility (a) Drawn (b) Available $ 500 $ 80 $ 420 (a) Expires in September 2027. (b) Includes outstanding letters of credit. All credit facility bank borrowings, outstanding letters of credit and outstanding commercial paper reduce the available capacity under the credit facility. SPS ha d no d irect advances on the credit facility outstanding as of March 31, 2023 and Dec. 31, 2022.

Revenues

Revenues	3 Months Ended
	Mar. 31, 2023
Revenue from Contract with Customer [Abstract]
Revenue	Revenue is classified by the type of goods/services rendered and market/customer type. SPS’ operating revenues consisted of the following: Three Months Ended March 31 (Millions of Dollars) 2023 2022 Major revenue types Revenue from contracts with customers: Residential $ 101 $ 97 Commercial and Industrial 267 222 Other 12 8 Total retail 380 327 Wholesale 45 69 Transmission 74 72 Other — 3 Total revenue from contracts with customers 499 471 Alternative revenue and other 9 6 Total revenues $ 508 $ 477

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	6. Income Taxes Reconciliation between the statutory rate and ETR: Three Months Ended March 31 2023 2022 Federal statutory rate 21.0 % 21.0 % State tax (net of federal tax effect) 2.3 2.5 Increases (decreases): Wind PTCs (a) (105.5) (87.2) Plant regulatory differences (b) (3.7) (4.0) Amortization of excess nonplant deferred taxes 0.3 (1.1) Other (net) (0.6) 1.1 Effective income tax rate (86.2) % (67.7) % (a) Wind PTCs are credited to customers (reduction to revenue) and do not materially impact net income.

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities	Fair Value Measurements Derivative Activities and Fair Value Measurements SPS enters into derivative instruments, including forward contracts, for trading purposes and to manage risk in connection with changes in interest rates and utility commodity prices. Interest Rate Derivatives — SPS enters into contracts that effectively fix the interest rate on a specified principal amount of a hypothetical future debt issuance. These financial swaps net settle based on changes in a specified benchmark interest rate, acting as a hedge of changes in market interest rates that will impact specified anticipated debt issuances. These derivative instruments are designated as cash flow hedges for accounting purposes, with changes in fair value prior to occurrence of the hedged transactions recorded as other comprehensive loss. As of March 31, 2023, accumulated other comprehensive loss related to interest rate derivatives included immaterial net losses expected to be reclassified into earnings during the next 12 months as the hedged transactions impact earnings. As of March 31, 2023, SPS had no unsettled interest rate derivatives. Wholesale and Commodity Trading — SPS conducts various wholesale and commodity trading activities, including the purchase and sale of electric capacity, energy and energy-related instruments, including derivatives. SPS is allowed to conduct these activities within guidelines and limitations as approved by its risk management committee, comprised of management personnel not directly involved in the activities governed by this policy. Results of derivative instrument transactions entered into for trading purposes are presented in the statements of income as electric revenues, net of any sharing with customers. These activities are not intended to mitigate commodity price risk associated with regulated electric operations. Sharing of these margins is determined through state regulatory proceedings as well as the operation of the FERC-approved joint operating agreement. Commodity Derivatives — SPS enters into derivative instruments to manage variability of future cash flows from changes in commodity prices in its electric utility operations. This could include the purchase or sale of energy or energy-related products and FTRs. The most significant derivative positions outstanding at March 31, 2023 for this purpose relate to FTR instruments administered by SPP. These instruments are intended to offset the impacts of transmission system congestion. Higher congestion costs in recent years have led to an increase in the fair value of FTRs. Settlements of FTRs are shared with electric customers through fuel and purchased energy cost-recovery mechanisms. When SPS enters into derivative instruments that mitigate commodity price risk on behalf of electric customers, the instruments are not typically designated as qualifying hedging transactions. The classification of unrealized losses or gains on these instruments as a regulatory asset or liability, if applicable, is based on approved regulatory recovery mechanisms. Gross notional amounts of FTRs: Amounts in Millions (a) March 31, 2023 Dec. 31, 2022 Megawatt hours of electricity 3 8 (a) Not reflective of net positions in the underlying commodities. Consideration of Credit Risk and Concentrations — SPS continuously monitors the creditworthiness of counterparties to its interest rate derivatives and commodity derivative contracts prior to settlement, and assesses each counterparty’s ability to perform on the transactions set forth in the contracts. Impact of credit risk was immaterial to the fair value of unsettled commodity derivatives presented on the balance sheets. SPS’ most significant concentrations of credit risk with particular entities or industries are contracts with counterparties to its wholesale, trading and non-trading commodity activities. At March 31, 2023, four of the ten most significant counterparties for these activities, comprising $10 million, or 31%, of this credit exposure, had investment grade credit ratings from S&P Global Ratings, Moody’s Investor Services or Fitch Ratings. Five of the ten most significant counterparties, comprising $23 million , or 69%, of this credit exposure, were not rated by external ratings agencies, but based on SPS’ internal analysis, had credit quality consistent with investment grade. One of these significant counterparties, comprising an immaterial amount or less than 1% of this credit exposure, had credit quality less than investment grade, based on internal analysis. Nine of these significant counterparties are municipal or cooperative electric entities, RTOs or other utilities. Recurring Derivative Fair Value Measurements Impact of derivative activity: Pre-Tax Fair Value (Losses) Recognized During the Period in: (Millions of Dollars) Regulatory Assets and Liabilities Three Months Ended March 31, 2023 Other derivative instruments Electric commodity $ (75) Total $ (75) Three Months Ended March 31, 2022 Other derivative instruments Electric commodity $ 1 Total $ 1 Pre-Tax Losses Reclassified into Income During the Period from: (Millions of Dollars) Regulatory Assets and Liabilities Three Months Ended March 31, 2023 Other derivative instruments Electric commodity 68 (a) Total $ 68 Three Months Ended March 31, 2022 Other derivative instruments Electric commodity 12 (a) Total $ 12 (a) Recorded to electric fuel and purchased power. These derivative settlement gains and losses are shared with electric customers through fuel and purchased energy cost-recovery mechanisms, and reclassified out of income as regulatory assets or liabilities, as appropriate. FTR settlements are shared with customers and do not have a material impact on net income. Presented amounts reflect changes in fair value between auction and settlement dates, but exclude the original auction fair value. SPS had no derivative instruments designated as fair value hedges during the three months ended March 31, 2023 and 2022. Derivative assets and liabilities measured at fair value on a recurring basis were as follows: March 31, 2023 Dec. 31, 2022 Fair Value Fair Value Total Netting (a) Total Fair Value Fair Value Total Netting (a) Total (Millions of Dollars) Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Current derivative assets Other derivative instruments: Electric commodity $ — $ — $ 23 $ 23 $ — $ 23 $ — $ — $ 119 $ 119 $ — $ 119 Total current derivative assets $ — $ — $ 23 $ 23 $ — 23 $ — $ — $ 119 $ 119 $ — 119 PPAs (b) 3 3 Current derivative instruments $ 26 $ 122 Noncurrent derivative assets PPAs (b) 2 3 Noncurrent derivative instruments $ 2 $ 3 Current derivative liabilities PPAs (b) 4 4 Current derivative instruments $ 4 $ 4 Noncurrent derivative liabilities PPAs (b) 1 2 Noncurrent derivative instruments $ 1 $ 2 (a) SPS nets derivative instruments and related collateral on its balance sheet when supported by a legally enforceable master netting agreement. At March 31, 2023 and Dec. 31, 2022, derivative assets and liabilities include no obligations to return cash collateral or rights to reclaim cash collateral. Counterparty netting amounts presented exclude settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements. (b) SPS currently applies the normal purchase exception to qualifying PPAs. Balance relates to specific contracts that were previously recognized at fair value prior to applying the normal purchase exception, and are being amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities. Changes in Level 3 commodity derivatives: Three Months Ended March 31 (Millions of Dollars) 2023 2022 Balance at Jan. 1 $ 119 $ 27 Purchases (a) 6 4 Settlements (a) (16) (33) Net transactions recorded during the period: Net (losses) gains recognized as regulatory assets and liabilities (a) (86) 34 Balance at March 31 $ 23 $ 32 (a) Relates primarily to FTR instruments administered by SPP. Fair Value of Long-Term Debt As of March 31, 2023, other financial instruments for which the carrying amount did not equal fair value: March 31, 2023 Dec. 31, 2022 (Millions of Dollars) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt $ 3,211 $ 2,770 $ 3,211 $ 2,674

Benefit Plans and Other Postret

Benefit Plans and Other Postretirement Benefits	3 Months Ended
	Mar. 31, 2023
Retirement Benefits [Abstract]
Benefit Plans and Other Postretirement Benefits	Components of Net Periodic Benefit Cost Three Months Ended March 31 2023 2022 (Millions of Dollars) Pension Benefits Service cost $ 2 $ 2 Interest cost (a) 6 4 Expected return on plan assets (a) (8) (8) Amortization of net loss (a) — 3 Net periodic benefit cost $ — $ 1 Effects of regulation 1 1 Net benefit cost recognized for financial reporting $ 1 $ 2 (a) The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the statements of income or capitalized on the balance sheets as a regulatory asset.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Legal SPS is involved in various litigation matters in the ordinary course of business. The assessment of whether a loss is probable or is a reasonable possibility, and whether the loss or a range of loss is estimable, often involves a series of complex judgments about future events. Management maintains accruals for losses probable of being incurred and subject to reasonable estimation. Management is sometimes unable to estimate an amount or range of a reasonably possible loss in certain situations, including but not limited to when (1) the damages sought are indeterminate, (2) the proceedings are in the early stages, or (3) the matters involve novel or unsettled legal theories. In such cases, there is considerable uncertainty regarding the timing or ultimate resolution, including a possible eventual loss. For current proceedings not specifically reported herein, management does not anticipate that the ultimate liabilities, if any, would have a material effect on SPS’ financial statements. Legal fees are generally expensed as incurred. Other Litigation — In 2019, SPS and Xcel Energy Services, Inc. were served with a lawsuit related to a traffic accident that resulted in two fatalities in New Mexico. A loss contingency of approximately $50 million was recorded as of Sept. 30, 2022 within Other current liabilities. In July 2022, a confidential settlement was reached. No impact to earnings has or is expected to occur, as the amounts are expected to be reimbursed by SPS’ insurers. An offsetting asset has been recorded to reflect the reimbursement within Prepayments and other current assets. Rate Matters and Other SPS is involved in various regulatory proceedings arising in the ordinary course of business. Until resolution, typically in the form of a rate order, uncertainties may exist regarding the ultimate rate treatment for certain activities and transactions. Amounts have been recognized for probable and reasonably estimable losses that may result. Unless otherwise disclosed, any reasonably possible range of loss in excess of any recognized amount is not expected to have a material effect on the financial statements. SPP OATT Upgrade Costs — Costs of transmission upgrades may be recovered from other SPP customers whose transmission service depends on capacity enabled by the upgrade under the SPP OATT. SPP had not been charging its customers for these upgrades, even though the SPP OATT had allowed SPP to do so since 2008. In 2016, the FERC granted SPP’s request to recover these previously unbilled charges and SPP subsequently billed SPS approximately $13 million. In 2018, SPS’ appeal to the D.C. Circuit over the FERC rulings granting SPP the right to recover previously unbilled charges was remanded to the FERC. In 2019, the FERC reversed its 2016 decision and ordered SPP to refund charges retroactively collected from its transmission customers, including SPS, related to periods before September 2015. In 2020, SPP and Oklahoma Gas & Electric separately filed petitions for review of the FERC’s orders at the D.C. Circuit. In 2021, the D.C. Circuit issued a decision denying these appeals and upholding the FERC’s orders. Refunds received by SPS are expected to be given back to SPS customers through future rates. In 2017, SPS filed a separate related complaint asserting SPP assessed upgrade charges to SPS in violation of the SPP OATT. In 2018, the FERC issued an order denying the SPS complaint. SPS filed a request for rehearing in 2018. The FERC subsequently issued a tolling order granting a rehearing for further consideration. If SPS’ complaint results in additional charges or refunds, SPS will seek to recover or refund the amount through future SPS customer rates. In 2020, SPS filed a petition for review of the FERC’s 2018 orders at the D.C. Circuit. In February 2022, FERC issued an order rejecting SPS’ request for hearing. SPS has appealed that order. That appeal has been combined with SPS’ prior appeal. Environmental MGP, Landfill and Disposal Sites SPS is remediating one former disposal site. SPS has recognized its best estimate of costs/liabilities from final resolution of these issues, however, the outcome and timing are unknown. In addition, there may be insurance recovery and/or recovery from other potentially responsible parties, offsetting a portion of costs incurred. Environmental Requirements — Air Regional Haze Rules — In 2016, the EPA adopted a final rule establishing a federal implementation plan for reasonable further progress under the regional haze program for the state of Texas. The rule imposes SO 2 emission limitations which would require the installation of dry scrubbers on Tolk Units 1 and 2; compliance would have been required by February 2021. SPS appealed the EPA’s decision and obtained a stay of the final rule. In 2017, the EPA adopted a final BART rule for Texas. Under that rule, Harrington Units 1, 2, and 3 and Tolk Units 1 and 2 participate in intrastate SO 2 budget and trading program. The rule also implemented participation in a federal ozone season NOx budget and trading program, named the Cross State Air Pollution Rule. The EPA is reconsidering this rule and a proposal for reconsideration is anticipated in the second quarter of 2023. Leases SPS evaluates contracts that may contain leases, including PPAs and arrangements for the use of office space and other facilities, vehicles and equipment. A contract contains a lease if it conveys the exclusive right to control the use of a specific asset. Components of lease expense: Three Months Ended March 31 (Millions of Dollars) 2023 2022 Operating leases PPA capacity payments $ 13 $ 13 Other operating leases (a) 1 2 Total operating lease expense (b) $ 14 $ 15 (a) Includes immaterial short-term lease expense for 2023 and 2022. (b) PPA capacity payments are included in electric fuel and purchased power on the statements of income. Expense for other operating leases is included in operating and maintenance expense and electric fuel and purchased power. Commitments under operating leases as of March 31, 2023: (Millions of Dollars) PPA Operating Leases Other Operating Leases Total Operating Leases Total minimum obligation $ 485 $ 52 $ 537 Interest component of obligation (98) (13) (111) Present value of minimum obligation $ 387 $ 39 426 Less current portion (31) Noncurrent operating lease liabilities $ 395 Variable Interest Entities Under certain PPAs, SPS purchases power from IPPs for which SPS is required to reimburse fuel costs, or to participate in tolling arrangements under which SPS procures the natural gas required to produce the energy that they purchase. These specific PPAs create a variable interest in the IPP. In addition, certain solar PPAs provide an option to purchase emission allowances or sharing provisions related to production credits generated by the solar facility under contract. These specific PPAs create a variable interest in the IPP. SPS had approxi mately 1,197 MW of capacity under long-term PPAs at both March 31, 2023 and Dec. 31, 2022 with entities that have been determined to be variable interest entities. SPS concluded that these entities are not required to be consolidated in its financial statements because it does not have the power to direct the activities that most significantly impact the entities’ economic performance. The PPAs have expiration dates through 2041.

Selected Balance Sheet Data (Ta

Selected Balance Sheet Data (Tables)	3 Months Ended
	Mar. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Accounts Receivable, Net	(Millions of Dollars) March 31, 2023 Dec. 31, 2022 Accounts receivable, net Accounts receivable $ 153 $ 180 Less allowance for bad debts (13) (13) Accounts receivable, net $ 140 $ 167
Inventories	(Millions of Dollars) March 31, 2023 Dec. 31, 2022 Inventories Materials and supplies $ 47 $ 42 Fuel 19 19 Total inventories $ 66 $ 61
Property, Plant and Equipment, Net	(Millions of Dollars) March 31, 2023 Dec. 31, 2022 Property, plant and equipment, net Electric plant $ 10,254 $ 10,182 Plant to be retired (a) 260 266 CWIP 239 167 Total property, plant and equipment 10,753 10,615 Less accumulated depreciation (2,543) (2,486) Property, plant and equipment, net $ 8,210 $ 8,129

Borrowings and Other Financin_2

Borrowings and Other Financing Instruments (Tables)	3 Months Ended
	Mar. 31, 2023
Borrowings and Other Financing Instruments [Abstract]
Credit Facilities	As of March 31, 2023, SPS had the following committed revolving credit facility available (in millions of dollars): Credit Facility (a) Drawn (b) Available $ 500 $ 80 $ 420 (a) Expires in September 2027. (b) Includes outstanding letters of credit.
Money Pool
Borrowings and Other Financing Instruments [Abstract]
Short-Term Borrowings	Money pool borrowings: (Amounts in Millions, Except Interest Rates) Three Months Ended March 31, 2023 Year Ended Dec. 31, 2022 Borrowing limit $ 100 $ 100 Amount outstanding at period end 5 — Average amount outstanding — 35 Maximum amount outstanding 5 100 Weighted average interest rate, computed on a daily basis 4.59 % 0.44 % Weighted average interest rate at period end 4.59 N/A
Commercial Paper
Borrowings and Other Financing Instruments [Abstract]
Short-Term Borrowings	Commercial paper outstanding: (Amounts in Millions, Except Interest Rates) Three Months Ended March 31, 2023 Year Ended Dec. 31, 2022 Borrowing limit $ 500 $ 500 Amount outstanding at period end 78 34 Average amount outstanding 88 100 Maximum amount outstanding 118 324 Weighted average interest rate, computed on a daily basis 4.86 % 0.79 % Weighted average interest rate at period end 5.58 4.55

Revenues (Tables)

Revenues (Tables)	3 Months Ended
	Mar. 31, 2023
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	SPS’ operating revenues consisted of the following: Three Months Ended March 31 (Millions of Dollars) 2023 2022 Major revenue types Revenue from contracts with customers: Residential $ 101 $ 97 Commercial and Industrial 267 222 Other 12 8 Total retail 380 327 Wholesale 45 69 Transmission 74 72 Other — 3 Total revenue from contracts with customers 499 471 Alternative revenue and other 9 6 Total revenues $ 508 $ 477

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	Reconciliation between the statutory rate and ETR: Three Months Ended March 31 2023 2022 Federal statutory rate 21.0 % 21.0 % State tax (net of federal tax effect) 2.3 2.5 Increases (decreases): Wind PTCs (a) (105.5) (87.2) Plant regulatory differences (b) (3.7) (4.0) Amortization of excess nonplant deferred taxes 0.3 (1.1) Other (net) (0.6) 1.1 Effective income tax rate (86.2) % (67.7) % (a) Wind PTCs are credited to customers (reduction to revenue) and do not materially impact net income.

Fair Value of Financial Asset_2

Fair Value of Financial Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Gross Notional Amounts of Commodity FTRs	Amounts in Millions (a) March 31, 2023 Dec. 31, 2022 Megawatt hours of electricity 3 8 (a) Not reflective of net positions in the underlying commodities.
Derivative Assets and Liabilities Measured at Fair Value on a Recurring Basis by Hierarchy Level	March 31, 2023 Dec. 31, 2022 Fair Value Fair Value Total Netting (a) Total Fair Value Fair Value Total Netting (a) Total (Millions of Dollars) Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Current derivative assets Other derivative instruments: Electric commodity $ — $ — $ 23 $ 23 $ — $ 23 $ — $ — $ 119 $ 119 $ — $ 119 Total current derivative assets $ — $ — $ 23 $ 23 $ — 23 $ — $ — $ 119 $ 119 $ — 119 PPAs (b) 3 3 Current derivative instruments $ 26 $ 122 Noncurrent derivative assets PPAs (b) 2 3 Noncurrent derivative instruments $ 2 $ 3 Current derivative liabilities PPAs (b) 4 4 Current derivative instruments $ 4 $ 4 Noncurrent derivative liabilities PPAs (b) 1 2 Noncurrent derivative instruments $ 1 $ 2 (a) SPS nets derivative instruments and related collateral on its balance sheet when supported by a legally enforceable master netting agreement. At March 31, 2023 and Dec. 31, 2022, derivative assets and liabilities include no obligations to return cash collateral or rights to reclaim cash collateral. Counterparty netting amounts presented exclude settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements. (b) SPS currently applies the normal purchase exception to qualifying PPAs. Balance relates to specific contracts that were previously recognized at fair value prior to applying the normal purchase exception, and are being amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities.
Changes in Level 3 Commodity Derivatives	Three Months Ended March 31 (Millions of Dollars) 2023 2022 Balance at Jan. 1 $ 119 $ 27 Purchases (a) 6 4 Settlements (a) (16) (33) Net transactions recorded during the period: Net (losses) gains recognized as regulatory assets and liabilities (a) (86) 34 Balance at March 31 $ 23 $ 32 (a) Relates primarily to FTR instruments administered by SPP.
Carrying Amount and Fair Value of Long-term Debt	March 31, 2023 Dec. 31, 2022 (Millions of Dollars) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt $ 3,211 $ 2,770 $ 3,211 $ 2,674

Benefit Plans and Other Postr_2

Benefit Plans and Other Postretirement Benefits (Tables)	3 Months Ended
	Mar. 31, 2023
Retirement Benefits [Abstract]
Components of Net Periodic Benefit Cost (Credit)	Components of Net Periodic Benefit Cost Three Months Ended March 31 2023 2022 (Millions of Dollars) Pension Benefits Service cost $ 2 $ 2 Interest cost (a) 6 4 Expected return on plan assets (a) (8) (8) Amortization of net loss (a) — 3 Net periodic benefit cost $ — $ 1 Effects of regulation 1 1 Net benefit cost recognized for financial reporting $ 1 $ 2 (a) The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the statements of income or capitalized on the balance sheets as a regulatory asset.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Lease, Cost	Components of lease expense: Three Months Ended March 31 (Millions of Dollars) 2023 2022 Operating leases PPA capacity payments $ 13 $ 13 Other operating leases (a) 1 2 Total operating lease expense (b) $ 14 $ 15 (a) Includes immaterial short-term lease expense for 2023 and 2022. (b) PPA capacity payments are included in electric fuel and purchased power on the statements of income. Expense for other operating leases is included in operating and maintenance expense and electric fuel and purchased power.
Lessee, Operating Lease, Liability, Maturity	Commitments under operating leases as of March 31, 2023: (Millions of Dollars) PPA Operating Leases Other Operating Leases Total Operating Leases Total minimum obligation $ 485 $ 52 $ 537 Interest component of obligation (98) (13) (111) Present value of minimum obligation $ 387 $ 39 426 Less current portion (31) Noncurrent operating lease liabilities $ 395

Selected Balance Sheet Data Acc

Selected Balance Sheet Data Accounts Receivable, Net (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Accounts receivable, net
Accounts receivable	$ 153	$ 180
Less allowance for bad debts	(13)	(13)
Accounts receivable, net	$ 140	$ 167

Selected Balance Sheet Data Sel

Selected Balance Sheet Data Selected Balance Sheet Data Inventories (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Inventories	$ 66	$ 61
Inventory, Net	66	61
Materials and supplies
Inventories	47	42
Fuel
Inventories	$ 19	$ 19

Selected Balance Sheet Data Bal

Selected Balance Sheet Data Balance Sheet Related Disclosures, Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions		Mar. 31, 2023	Dec. 31, 2022
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 10,753	$ 10,615
Accumulated depreciation		(2,543)	(2,486)
Property, plant and equipment, net		8,210	8,129
Electric plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		10,254	10,182
Plant to be Retired
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	[1]	260	266
Construction work in progress
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 239	$ 167
[1]Amounts include Tolk and coal generation assets at Harrington pending facility gas conversion and are reported net of accumulated depreciation.

Borrowings and Other Financin_3

Borrowings and Other Financing Instruments - Money Pool (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Short-term Debt [Line Items]
Short-term debt	$ 78	$ 34
Money Pool
Short-term Debt [Line Items]
Borrowing limit	100	100
Short-term debt	5	0
Average amount outstanding	0	35
Maximum amount outstanding	$ 5	$ 100
Weighted average interest rate, computed on a daily basis	4.59%	0.44%
Weighted average interest rate at period end	4.59%
Commercial Paper
Short-term Debt [Line Items]
Borrowing limit	$ 500	$ 500
Short-term debt	78	34
Average amount outstanding	88	100
Maximum amount outstanding	$ 118	$ 324
Weighted average interest rate, computed on a daily basis	4.86%	0.79%
Weighted average interest rate at period end	5.58%	4.55%

Borrowings and Other Financin_4

Borrowings and Other Financing Instruments - Commercial Paper (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Short-term Debt [Line Items]
Short-term debt	$ 78	$ 34
Commercial Paper
Short-term Debt [Line Items]
Borrowing limit	500	500
Short-term debt	78	34
Average amount outstanding	88	100
Maximum amount outstanding	$ 118	$ 324
Weighted average interest rate, computed on a daily basis	4.86%	0.79%
Weighted average interest rate at period end	5.58%	4.55%

Borrowings and Other Financin_5

Borrowings and Other Financing Instruments - Letters of Credit (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Line of Credit Facility [Line Items]
Short-term debt	$ 78,000,000	$ 34,000,000
Letter of Credit
Line of Credit Facility [Line Items]
Short-term debt	$ 2,000,000	2,000,000
Debt Instrument, Term	1 year
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Direct advances on the credit facility outstanding	$ 0	$ 0

Borrowings and Other Financin_6

Borrowings and Other Financing Instruments - Credit Facility (Details)		3 Months Ended
		Mar. 31, 2023 USD ($) Plan	Dec. 31, 2022 USD ($)
Line of Credit Facility [Line Items]
Number of extension you can request | Plan		2
Credit Facility
Line of Credit Facility [Line Items]
Credit Facility	[1]	$ 500,000,000
Outstanding	[2]	80,000,000
Available		420,000,000
Direct advances on the credit facility outstanding		$ 0	$ 0
[1]Expires in September 2027[2]Includes outstanding letters of credit.

Borrowings and Other Financin_7

Borrowings and Other Financing Instruments - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
Short-term debt	$ 78	$ 34

Revenues (Details)

Revenues (Details) - Regulated Electric - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 499	$ 471
Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	508	477
Retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	380	327
Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	101	97
Retail | C&I
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	267	222
Retail | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	12	8
Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	45	69
Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	74	72
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	3
Alternative and Other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	$ 9	$ 6

Income Taxes (Details)

Income Taxes (Details)		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Federal statutory rate, percent		21%	21%
State tax (net of federal tax effect), percent		2.30%	2.50%
Wind PTCs, percent	[1]	(105.50%)	(87.20%)
Plant regulatory differences, percent	[2]	(3.70%)	(4.00%)
Other tax credits, percent		0.30%	(1.10%)
Other (net), percent		(0.60%)	1.10%
Effective income tax rate, percent		(86.20%)	(67.70%)
[1]Wind PTCs are credited to customers (reduction to revenue) and do not materially impact net income.[2]Regulatory differences for income tax primarily relate to the credit of excess deferred taxes to customers through the average rate assumption method. Income tax benefits associated with the credit of excess deferred taxes are offset by corresponding revenue reductions.

Fair Value of Financial Asset_3

Fair Value of Financial Assets and Liabilities - Commodity Derivatives (Details) - MWh MWh in Millions		Mar. 31, 2023	Dec. 31, 2022
Electric Commodity [Member]
Derivative [Line Items]
Mwh of electricity	[1]	3	8
[1]ot reflective of net positions in the underlying commodities.

Fair Value of Financial Asset_4

Fair Value of Financial Assets and Liabilities - Consideration of Credit Risk Concentrations (Details) - Credit Concentration Risk $ in Millions	Mar. 31, 2023 USD ($) Counterparty
Derivative [Line Items]
Significant counterparties	10
Municipal or cooperative electric entities or other utilities
Derivative [Line Items]
Significant counterparties	9
External credit rating, investment grade
Derivative [Line Items]
Significant counterparties	4
Credit exposure | $	$ 10
Credit exposure, percentage	31%
Internal investment grade
Derivative [Line Items]
Significant counterparties	5
Credit exposure | $	$ 23
Credit exposure, percentage	69%
External Credit Rating, Non Investment Grade [Member]
Derivative [Line Items]
Significant counterparties	1
Credit exposure, percentage	1%

Fair Value of Financial Asset_5

Fair Value of Financial Assets and Liabilities - Impact of Derivative Activities on Income and Accumulated Other Comprehensive Loss (Details) - USD ($)		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract]
Derivative instruments designated as fair value hedges		$ 0	$ 0
Interest Rate Swap [Member]
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract]
Derivative Liability, Notional Amount		0
Other Derivative Instruments
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract]
Changes in fair value of FTRs pre-tax gains		(75,000,000)
FTR settlement gains		(68,000,000)	(12,000,000)
Other Derivative Instruments | Electric Commodity
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract]
Changes in fair value of FTRs pre-tax gains		(75,000,000)	1,000,000
FTR settlement gains	[1]	$ 68,000,000	$ 12,000,000
[1]Recorded to electric fuel and purchased power. These derivative settlement gains and losses are shared with electric customers through fuel and purchased energy cost-recovery mechanisms, and reclassified out of income as regulatory assets or liabilities, as appropriate. FTR settlements are shared with customers and do not have a material impact on net income. Presented amounts reflect changes in fair value between auction and settlement dates, but exclude the original auction fair value.

Fair Value of Financial Asset_6

Fair Value of Financial Assets and Liabilities - Recurring Fair Value Measurements (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Derivatives, Fair Value
Return Cash Collateral				$ 0
External credit rating, investment grade | Credit Concentration Risk
Changes in Level 3 Commodity Derivatives
Credit exposure, percentage		31%
Commodity Contract [Member]
Changes in Level 3 Commodity Derivatives
Balance at beginning of period		$ 119	$ 27
Purchases	[1]	6	4
Settlements	[1]	(16)	(33)
Net gains recognized as regulatory assets and liabilities	[1]	(86)	34
Balance at end of period		23	$ 32
Other Current Assets
Derivatives, Fair Value
Derivative asset, net		26		122
Other Noncurrent Assets
Derivatives, Fair Value
Derivative asset, net		2		3
Other Current Liabilities
Derivatives, Fair Value
Derivative liability, net		4		4
Other Noncurrent Liabilities
Derivatives, Fair Value
Derivative liability, net		1		2
Fair Value Measured on a Recurring Basis
Derivatives, Fair Value
Derivative asset, gross		23		119
Asset, netting	[2]	0		0
Derivative asset, net		23		119
Fair Value Measured on a Recurring Basis | Level 1
Derivatives, Fair Value
Derivative asset, gross		0		0
Fair Value Measured on a Recurring Basis | Level 2
Derivatives, Fair Value
Derivative asset, gross		0		0
Fair Value Measured on a Recurring Basis | Level 3
Derivatives, Fair Value
Derivative asset, gross		23		119
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Electric Commodity
Derivatives, Fair Value
Derivative asset, gross		23		119
Asset, netting	[2]	0		0
Derivative asset, net		23		119
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 1 | Electric Commodity
Derivatives, Fair Value
Derivative asset, gross		0		0
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 2 | Electric Commodity
Derivatives, Fair Value
Derivative asset, gross		0		0
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 3 | Electric Commodity
Derivatives, Fair Value
Derivative asset, gross		23		119
Fair Value, Measurements, Nonrecurring | Other Current Assets | PPAs
Derivatives, Fair Value
Derivative asset, net	[3]	3		3
Fair Value, Measurements, Nonrecurring | Other Noncurrent Assets | PPAs
Derivatives, Fair Value
Derivative asset, net	[3]	2		3
Fair Value, Measurements, Nonrecurring | Other Current Liabilities | PPAs
Derivatives, Fair Value
Derivative liability, net	[3]	4		4
Fair Value, Measurements, Nonrecurring | Other Noncurrent Liabilities | PPAs
Derivatives, Fair Value
Derivative liability, net	[3]	$ 1		$ 2
[1]Relates primarily to FTR instruments administered by SPP.[2]SPS nets derivative instruments and related collateral on its balance sheet when supported by a legally enforceable master netting agreement. At March 31, 2023 and Dec. 31, 2022, derivative assets and liabilities include no obligations to return cash collateral or rights to reclaim cash collateral. Counterparty netting amounts presented exclude settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.[3]SPS currently applies the normal purchase exception to qualifying PPAs. Balance relates to specific contracts that were previously recognized at fair value prior to applying the normal purchase exception, and are being amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities.

Fair Value of Financial Asset_7

Fair Value of Financial Assets and Liabilities - Fair Value of Long-Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Amount	$ 3,211	$ 3,211
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 2,770	$ 2,674

Benefit Plans and Other Postr_3

Benefit Plans and Other Postretirement Benefits (Details) - Pension Plan [Member] - USD ($) $ in Millions		1 Months Ended	3 Months Ended
		Jan. 31, 2023	Mar. 31, 2023	Mar. 31, 2022
Components of Net Periodic Benefit Cost (Credit) [Abstract]
Service cost			$ 2	$ 2
Interest cost (a)	[1]		6	4
Expected return on plan assets (a)	[1]		(8)	(8)
Amortization of net loss (gain) (a)	[1]		0	3
Net periodic benefit cost (credit)			0	1
Contributions to pension plans		$ 0
Defined Benefit Plan Credits Not Recognized Due To Effects of Regulation			1	1
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)			$ 1	$ 2
Xcel Energy Inc.
Components of Net Periodic Benefit Cost (Credit) [Abstract]
Contributions to pension plans		$ 50
[1]The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the statements of income or capitalized on the balance sheets as a regulatory asset.

Commitments and Contingencies -

Commitments and Contingencies - SPP OATT Upgrade Costs (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)
Southwest Power Pool (SPP) | SPP Open Access Transmission Tariff Upgrade Costs | SPS
Public Utilities, General Disclosures [Line Items]
Charges For Transmission Service Upgrades	$ 13

FERC NOPR on ROE Incentive Adde

FERC NOPR on ROE Incentive Adders (Details)	Mar. 31, 2023
Other MGP, Landfill, or Disposal Sites
Public Utilities, General Disclosures [Line Items]
Number of identified MGP, landfill, or disposal sites under current investigation and/or remediation	1

Leases (Details)

Leases (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	[1]	$ 14	$ 15
Lessee, Operating Lease, Liability, to be Paid		537
Lessee, Operating Lease, Liability, Undiscounted Excess Amount		(111)
Operating Lease, Liability		426
Operating Lease, Liability, Current		(31)		$ (31)
Operating lease liabilities		395		$ 403
PPAs
Lessee, Lease, Description [Line Items]
Operating Lease, Cost		13	13
Lessee, Operating Lease, Liability, to be Paid		485
Lessee, Operating Lease, Liability, Undiscounted Excess Amount		(98)
Operating Lease, Liability		387
Property, Plant and Equipment, Other Types
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	[2]	1	$ 2
Lessee, Operating Lease, Liability, to be Paid		52
Lessee, Operating Lease, Liability, Undiscounted Excess Amount		(13)
Operating Lease, Liability		$ 39
[1]PPA capacity payments are included in electric fuel and purchased power on the statements of income. Expense for other operating leases is included in operating and maintenance expense and electric fuel and purchased power.[2]Includes immaterial short-term lease expense for 2023 and 2022.

Commitments and Contingencies_2

Commitments and Contingencies - Variable Interest Entities (Details) - MW	Mar. 31, 2023	Dec. 31, 2022
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Purchased Power Agreements [Abstract]
Generating capacity (in MW)	1,197	1,197

Other Comprehensive Income (Det

Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income Tax Expense (Benefit)	$ (25)	$ (21)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive loss at beginning of period	3,850
Accumulated other comprehensive loss at end of period	$ 3,838