Northern States Power 10-Q1 Aug 242024 Q2 Quarterly reportFinancial data

Company Profile

Cover Page

Cover Page - shares	6 Months Ended
Cover Page - shares	Jun. 30, 2024	Aug. 01, 2024
Cover [Abstract]
Entity Registrant Name	NORTHERN STATES POWER CO
Entity Central Index Key	0001123852
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q2
Amendment Flag	false
Document Period End Date	Jun. 30, 2024
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-31387
Entity Incorporation, State or Country Code	MN
Entity Tax Identification Number	41-1967505
Entity Address, Address Line One	414 Nicollet Mall
Entity Address, City or Town	Minneapolis
Entity Address, State or Province	MN
Entity Address, Postal Zip Code	55401
City Area Code	(612)
Local Phone Number	330-5500
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		1,000,000

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024		Jun. 30, 2023
Operating revenues
Electric, non-affiliates	$ 1,117	$ 1,076	$ 2,250		$ 2,207
Electric, affiliates	120	113	242		238
Natural gas	90	98	363		498
Other	3	12	11		22
Total operating revenues	1,330	1,299	2,866	[1],[2]	2,965	[1],[2]
Operating expenses
Electric fuel and purchased power	464	518	923		1,023
Cost of natural gas sold and transported	23	45	162		342
Cost of sales — other	0	7	4		14
Operating and maintenance expenses	328	326	623		651
Conservation program expenses	42	25	90		56
Depreciation and amortization	272	202	540		464
Taxes (other than income taxes)	52	32	120		110
Total operating expenses	1,181	1,155	2,462		2,660
Operating income	149	144	404		305
Other income, net	3	2	8		2
Allowance for funds used during construction — equity	13	9	24		17
Interest charges and financing costs
Interest charges and other financing costs	91	83	179		160
Allowance for funds used during construction — debt	(6)	(5)	(11)		(10)
Total interest charges and financing costs	85	78	168		150
Income before income taxes	80	77	268		174
Income tax benefit	(51)	(50)	(74)		(92)
Net income	$ 131	$ 127	$ 342		$ 266

[1] Operating revenues include an immaterial amount of affiliate gas revenue for the six months ended June 30, 2024 and 2023. Total revenues include $242 million and $238 million of affiliate electric revenue for the six months ended June 30, 2024 and 2023.

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Comprehensive income:
Net income	$ 131	$ 127	$ 342	$ 266
Derivative instruments:
Net fair value increase, net of tax	0	6	12	3
Total other comprehensive income	0	6	12	3
Total comprehensive income	$ 131	$ 133	$ 354	$ 269

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Operating activities
Net income	$ 342	$ 266
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	544	466
Nuclear fuel amortization	53	53
Deferred income taxes	160	(65)
Allowance for equity funds used during construction	(24)	(17)
Provision for bad debts	8	13
Changes in operating assets and liabilities:
Accounts receivable	16	43
Accrued unbilled revenues	(10)	81
Inventories	1	35
Other current assets	(46)	2
Accounts payable	23	(81)
Net regulatory assets and liabilities	(29)	192
Other current liabilities	(270)	95
Pension and other employee benefit obligations	(43)	(19)
Other, net	15	9
Net cash provided by operating activities	740	1,073
Investing activities
Capital/construction expenditures	(1,308)	(1,103)
Purchase of investment securities	(469)	(416)
Proceeds from the sale of investment securities	450	398
Investments in utility money pool arrangement	(357)	(69)
Repayments from utility money pool arrangement	414	5
Other, net	(3)	(2)
Net cash used in investing activities	(1,273)	(1,187)
Financing activities
Repayments of short-term borrowings, net	(165)	(207)
Borrowings under utility money pool arrangement	100	189
Repayments under utility money pool arrangement	(100)	(189)
Proceeds from issuance of long-term debt	687	783
Repayment of long-term debt	0	(400)
Capital contributions from parent	499	251
Dividends paid to parent	(222)	(254)
Net cash provided by financing activities	799	173
Net change in cash, cash equivalents and restricted cash	266	59
Cash, cash equivalents and restricted cash at beginning of period	34	65
Cash, cash equivalents and restricted cash at end of period	300	124
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(149)	(137)
Cash received from income taxes, net; includes proceeds from tax credit transfers	193	43
Other Noncash Investing and Financing Items [Abstract]
Accrued property, plant and equipment additions	217	158
Inventory transfers to property, plant and equipment	21	26
Allowance for equity funds used during construction	24	17
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 39	$ 29

CONSOLIDATED BALANCE SHEETS (UN

CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Current assets
Cash, cash equivalents and restricted cash at beginning of period	$ 300	$ 34
Investments in money pool arrangements	0	57
Accrued unbilled revenues	301	290
Inventories	334	356
Regulatory assets	364	250
Derivative instruments	83	50
Prepayments and other	135	87
Total current assets	1,998	1,629
Property, plant and equipment, net	19,572	18,757
Other assets
Nuclear decommissioning fund and other investments	3,443	3,262
Regulatory assets	807	837
Derivative instruments	73	61
Operating lease right-of-use assets	435	439
Other	18	16
Total other assets	4,776	4,615
Total assets	26,346	25,001
Current liabilities
Short-term debt	0	165
Regulatory liabilities	362	300
Taxes accrued	175	223
Accrued interest	92	79
Dividends payable to parent	103	121
Derivative instruments	38	44
Operating lease liabilities	94	91
Other	146	351
Total current liabilities	1,655	2,042
Deferred credits and other liabilities
Deferred income taxes	2,210	1,992
Deferred investment tax credits	13	14
Regulatory liabilities	2,206	2,097
Asset retirement obligations	2,775	2,658
Derivative instruments	91	86
Pension and employee benefit obligations	131	168
Operating lease liabilities	363	372
Other	27	35
Total deferred credits and other liabilities	7,816	7,422
Capitalization
Long-term debt	8,020	7,330
Common stock — 5,000,000 shares authorized of $0.01 par value; 1,000,000 shares outstanding at June 30, 2024 and Dec. 31, 2023, respectively	$ 0	$ 0
Common Stock, Shares Authorized	5,000,000	5,000,000
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares, Outstanding	1,000,000	1,000,000
Additional paid in capital	$ 6,184	$ 5,686
Retained earnings	2,679	2,541
Accumulated other comprehensive loss	(8)	(20)
Total common stockholder's equity	8,855	8,207
Total liabilities and equity	26,346	25,001
Related Party
Current assets
Accounts receivable, net	462	490
Current liabilities
Accounts payable	589	579
Affiliated Entity
Current assets
Accounts receivable, net	19	15
Current liabilities
Accounts payable	$ 56	$ 89

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
Balance (in shares) at Dec. 31, 2022		1,000,000
Beginning balance at Dec. 31, 2022	$ 7,836	$ 0	$ 5,374	$ 2,480	$ (18)
Increase (Decrease) in Stockholders' Equity
Net income	266			266
Other comprehensive income	3				3
Dividends declared on common stock	(244)			(244)
Contribution of capital by parent	211		211
Balance (in shares) at Jun. 30, 2023		1,000,000
Ending balance at Jun. 30, 2023	8,072	$ 0	5,585	2,502	(15)
Balance (in shares) at Mar. 31, 2023		1,000,000
Beginning balance at Mar. 31, 2023	7,950	$ 0	5,484	2,487	(21)
Increase (Decrease) in Stockholders' Equity
Net income	127			127
Other comprehensive income	6				6
Dividends declared on common stock	(112)			(112)
Contribution of capital by parent	101		101
Balance (in shares) at Jun. 30, 2023		1,000,000
Ending balance at Jun. 30, 2023	$ 8,072	$ 0	5,585	2,502	(15)
Balance (in shares) at Dec. 31, 2023	1,000,000	1,000,000
Beginning balance at Dec. 31, 2023	$ 8,207	$ 0	5,686	2,541	(20)
Increase (Decrease) in Stockholders' Equity
Net income	342			342
Other comprehensive income	12				12
Dividends declared on common stock	(204)			(204)
Contribution of capital by parent	$ 498		498
Balance (in shares) at Jun. 30, 2024	1,000,000	1,000,000
Ending balance at Jun. 30, 2024	$ 8,855	$ 0	6,184	2,679	(8)
Balance (in shares) at Mar. 31, 2024		1,000,000
Beginning balance at Mar. 31, 2024	8,674	$ 0	6,031	2,651	(8)
Increase (Decrease) in Stockholders' Equity
Net income	131			131
Other comprehensive income	0
Dividends declared on common stock	(103)			(103)
Contribution of capital by parent	$ 153		153
Balance (in shares) at Jun. 30, 2024	1,000,000	1,000,000
Ending balance at Jun. 30, 2024	$ 8,855	$ 0	$ 6,184	$ 2,679	$ (8)

Management's Opinion

Management's Opinion	6 Months Ended
Management's Opinion	Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Management's Opinion	In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments necessary to present fairly, in accordance with GAAP, the financial position of NSP-Minnesota and its subsidiaries as of June 30, 2024 and Dec. 31, 2023; the results of NSP-Minnesota’s operations, including the components of net income, comprehensive income and changes in stockholder’s equity for the three and six months ended June 30, 2024 and 2023; and NSP-Minnesota’s cash flows for the six months ended June 30, 2024 and 2023. All adjustments are of a normal, recurring nature, except as otherwise disclosed. Management has also evaluated the impact of events occurring after June 30, 2024 up to the date of issuance of these consolidated financial statements. These statements contain all necessary adjustments and disclosures resulting from that evaluation. The Dec. 31, 2023 balance sheet information has been derived from the audited 2023 consolidated financial statements included in the NSP-Minnesota Annual Report on Form 10-K for the year ended Dec. 31, 2023. Notes to the consolidated 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 consolidated financial statements and notes thereto included in the NSP-Minnesota Annual Report on Form 10-K for the year ended Dec. 31, 2023, filed with the SEC on Feb. 21, 2024. Due to the seasonality of NSP-Minnesota’s electric and natural gas sales, interim results are not necessarily an appropriate base from which to project annual results.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
Summary of Significant Accounting Policies	Jun. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	The significant accounting policies set forth in Note 1 to the consolidated financial statements in the NSP-Minnesota Annual Report on Form 10-K for the year ended Dec. 31, 2023 appropriately represent, in all material respects, the current status of accounting policies and are incorporated herein by reference.

Accounting Pronouncements

Accounting Pronouncements	6 Months Ended
Accounting Pronouncements	Jun. 30, 2024
Accounting Standards Update and Change in Accounting Principle [Abstract]
Accounting Pronouncements	Recently Issued Segment Reporting — In November 2023, the FASB issued ASU 2023-07 – Segment Reporting (Topic 280) – Improvements to Reportable Segment Disclosures , which extends the existing requirements for annual disclosures to quarterly periods, and requires that both annual and quarterly disclosures present segment expenses using line items consistent with information regularly provided to the chief operating decision maker. The ASU is effective for annual periods beginning after Dec. 15, 2023 and quarterly periods beginning after Dec. 15, 2024, and NSP-Minnesota does not expect implementation of the new disclosure guidance to have a material impact to its consolidated financial statements. Income Taxes — In December 2023, the FASB issued ASU 2023-09 – Income Taxes (Topic 740) – Improvements to Income Tax Disclosures , with new disclosure requirements including presentation of prescribed line items in the effective tax rate reconciliation and disclosures regarding state and local tax payments. The ASU is effective for annual periods beginning after Dec. 15, 2024, and NSP-Minnesota does not expect implementation of the new disclosure guidance to have a material impact to its consolidated financial statements. Climate-Related Disclosures — In March 2024, the SEC issued Final Rule 33-11275 – The Enhancement and Standardization of Climate-Related Disclosures for Investors. This rule requires registrants to provide standardized disclosures in Form 10-K related to climate-related risks, Scope 1 and 2 greenhouse gas emissions, as well as to include in a footnote to the consolidated financial statements the financial impact of severe weather events and other natural conditions. The rule requires implementation in phases between 2025 and 2033. In April 2024, the SEC announced that it would voluntarily stay its final climate disclosure rules pending judicial review. NSP-Minnesota does not expect implementation of the new guidance to have a material impact on the consolidated financial statements.

Selected Balance Sheet Data

Selected Balance Sheet Data	6 Months Ended
Selected Balance Sheet Data	Jun. 30, 2024
Balance Sheet Related Disclosures [Abstract]
Selected Balance Sheet Data	(Millions of Dollars) June 30, 2024 Dec. 31, 2023 Accounts receivable, net Accounts receivable $ 501 $ 538 Less allowance for bad debts (39) (48) Accounts receivable, net $ 462 $ 490 (Millions of Dollars) June 30, 2024 Dec. 31, 2023 Inventories Materials and supplies $ 226 $ 219 Fuel 98 105 Natural gas 10 32 Total inventories $ 334 $ 356 (Millions of Dollars) June 30, 2024 Dec. 31, 2023 Property, plant and equipment, net Electric plant $ 21,780 $ 21,206 Natural gas plant 2,312 2,256 Common and other property 1,346 1,301 Plant to be retired (a) 575 604 Construction work in progress 1,607 1,085 Total property, plant and equipment 27,620 26,452 Less accumulated depreciation (8,451) (8,044) Nuclear fuel 3,444 3,337 Less accumulated amortization (3,041) (2,988) Property, plant and equipment, net $ 19,572 $ 18,757 (a) Amounts include Sherco 1 and 3 and A.S. King. Balance is presented net of accumulated depreciation.

Borrowings and Other Financing

Borrowings and Other Financing Instruments	6 Months Ended
Borrowings and Other Financing Instruments	Jun. 30, 2024
Debt Disclosure [Abstract]
Borrowings and Other Financing Instruments	Short-Term Borrowings NSP-Minnesota 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 June 30, 2024 Year Ended Dec. 31, 2023 Borrowing limit $ 250 $ 250 Amount outstanding at period end — — Average amount outstanding — 17 Maximum amount outstanding N/A 135 Weighted average interest rate, computed on a daily basis N/A 4.97 % Weighted average interest rate at period end N/A N/A Commercial Paper — Commercial paper outstanding: (Amounts in Millions, Except Interest Rates) Three Months Ended June 30, 2024 Year Ended Dec. 31, 2023 Borrowing limit $ 700 $ 700 Amount outstanding at period end — 165 Average amount outstanding — 92 Maximum amount outstanding N/A 441 Weighted average interest rate, computed on a daily basis N/A 4.99 % Weighted average interest rate at period end N/A 5.47 Letters of Credit — NSP-Minnesota uses letters of credit, generally with terms of one year, to provide financial guarantees for certain obligations. There w er e $12 million and $15 million of letters of credit outstanding under the credit facility at June 30, 2024 and Dec. 31, 2023, respectively. Amounts approximate their fair value and are subject to fees. Revolving Credit Facility — In order to issue its commercial paper, NSP-Minnesota must have a revolving credit facility equal to 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. NSP-Minnesota 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. At June 30, 2024, NSP-Minnesota had the following committed revolving credit facility available (in millions of dollars): Credit Facility (a) Drawn (b) Available $ 700 $ 12 $ 688 (a) Expires in September 2027. (b) Includes outstanding commercial paper and letters of credit. All credit facility bank borrowings, outstanding letters of credit and outstanding commercial paper reduce the available capacity under the credit facility. NSP-Minnesota had no direct advances on the credit facility outstanding at June 30, 2024 and Dec. 31, 2023. Bilateral Credit Agreement — In April 2024, NSP-Minnesota’s uncommitted bilateral credit agreement was renewed for an additional one-year term. The credit agreement is limited in use to support letters of credit. As of June 30, 2024, NSP-Minnesota had $70 million of outstanding letters of credit under the $75 million bilateral credit agreement. Long-Term Borrowings During the six months ended June 30, 2024, NSP-Minnesota issued $700 million of 5.40% first mortgage bonds due March 15, 2054.

Revenues

Revenues	6 Months Ended
Revenues	Jun. 30, 2024
Revenue from Contract with Customer [Abstract]
Revenues	Revenue is classified by the type of goods/services rendered and market/customer type. NSP-Minnesota’s operating revenues consisted of the following: Three Months Ended June 30, 2024 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 350 $ 37 $ — $ 387 C&I 571 25 — 596 Other 10 — 3 13 Total retail 931 62 3 996 Wholesale 57 — — 57 Transmission 56 — — 56 Interchange and other 115 11 — 126 Total revenue from contracts with customers 1,159 73 3 1,235 Alternative revenue and other 78 17 — 95 Total revenues $ 1,237 $ 90 $ 3 $ 1,330 Three Months Ended June 30, 2023 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 317 $ 42 $ 10 $ 369 C&I 517 40 — 557 Other 9 — 2 11 Total retail 843 82 12 937 Wholesale 80 — — 80 Transmission 66 — — 66 Interchange and other 108 3 — 111 Total revenue from contracts with customers 1,097 85 12 1,194 Alternative revenue and other 92 13 — 105 Total revenues $ 1,189 $ 98 $ 12 $ 1,299 Six Months Ended June 30, 2024 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 718 $ 175 $ 7 $ 900 C&I 1,093 115 — 1,208 Other 19 4 23 Total retail 1,830 290 11 2,131 Wholesale 132 — — 132 Transmission 119 — — 119 Interchange and other 240 28 — 268 Total revenue from contracts with customers 2,321 318 11 2,650 Alternative revenue and other 171 45 — 216 Total revenues $ 2,492 $ 363 $ 11 $ 2,866 Six Months Ended June 30, 2023 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 675 $ 249 $ 19 $ 943 C&I 1,060 213 — 1,273 Other 17 — 3 20 Total retail 1,752 462 22 2,236 Wholesale 184 — — 184 Transmission 130 — — 130 Interchange and other 234 5 — 239 Total revenue from contracts with customers 2,300 467 22 2,789 Alternative revenue and other 145 31 — 176 Total revenues $ 2,445 $ 498 $ 22 $ 2,965

Income Taxes

Income Taxes	6 Months Ended
Income Taxes	Jun. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	6. Income Taxes Reconciliation between the statutory rate and ETR: Six Months Ended June 30 2024 2023 Federal statutory rate 21.0 % 21.0 % State tax (net of federal tax effect) 7.0 7.0 (Decreases) increases: Wind PTCs (a) (49.9) (74.7) Plant regulatory differences (b) (5.4) (6.7) Other tax credits, net operating loss & tax credit allowances (1.1) (1.5) Other, net 0.8 2.0 Effective income tax rate (27.6) % (52.9) % (a) Wind PTCs net of estimated transfer discounts are credited to customers (reduction to revenue) and do not materially impact net income. (b) Plant regulatory differences primarily relate to the credit of excess deferred taxes to customers. Income tax benefits associated with the credit are offset by corresponding revenue reductions.

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities	6 Months Ended
Fair Value of Financial Assets and Liabilities	Jun. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities	7. Fair Value of Financial Assets and Liabilities Fair Value Measurements Accounting guidance for fair value measurements and disclosures provides a hierarchical framework for disclosing the observability of the inputs utilized in measuring assets and liabilities at fair value. • Level 1 — Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. The types of assets and liabilities included in Level 1 are actively traded instruments with observable actual trading prices. • Level 2 — Pricing inputs are other than actual trading prices in active markets, but are either directly or indirectly observable as of the reporting date. The types of assets and liabilities included in Level 2 are typically either comparable to actively traded securities or contracts, or priced with models using highly observable inputs. • Level 3 — Significant inputs to pricing have little or no observability as of the reporting date. The types of assets and liabilities included in Level 3 include those valued with models requiring significant judgment or estimation. Specific valuation methods include: Investments in equity securities and other funds — Equity securities are valued using quoted prices in active markets. The fair values for commingled funds are measured using NAVs. The investments in commingled funds may be redeemed for NAV with proper notice. Private equity commingled funds require approval of the fund for any unscheduled redemption, and such redemptions may be approved or denied by the fund at its sole discretion. Unscheduled distributions from real estate commingled funds may be redeemed with proper notice, however, withdrawals may be delayed or discounted as a result of fund illiquidity. Investments in debt securities — Fair values for debt securities are determined by a third party pricing service using recent trades and observable spreads from benchmark interest rates for similar securities. Interest rate derivatives — Fair values of interest rate derivatives are based on broker quotes that utilize current market interest rate forecasts. Commodity derivatives — Methods used to measure the fair value of commodity derivative forwards and options utilize forward prices and volatilities, as well as pricing adjustments for specific delivery locations, and are generally assigned a Level 2 classification. When contracts relate to inactive delivery locations or extend to periods beyond those readily observable on active exchanges, the significance of the use of less observable inputs on a valuation is evaluated and may result in Level 3 classification. Electric commodity derivatives held by NSP-Minnesota include transmission congestion instruments, generally referred to as FTRs. FTRs purchased from an RTO are financial instruments that entitle or obligate the holder to monthly revenues or charges based on transmission congestion across a given transmission path. The values of these instruments are derived from, and designed to offset, the costs of transmission congestion. In addition to overall transmission load, congestion is also influenced by the operating schedules of power plants and the consumption of electricity pertinent to a given transmission path. Unplanned plant outages, scheduled plant maintenance, changes in the relative costs of fuels used in generation, weather and overall changes in demand for electricity can each impact the operating schedules of the power plants on the transmission grid and the value of these instruments. FTRs are recognized at fair value and adjusted each period prior to settlement. Given the limited observability of certain variables underlying the reported auction values of FTRs, these fair value measurements have been assigned a Level 3 classification . Net congestion costs, including the impact of FTR settlements are shared through fuel and purchased energy cost recovery mechanisms. As such, the fair value of the unsettled instruments (i.e., derivative asset or liability) is offset/deferred as a regulatory asset or liability. Non-Derivative Fair Value Measurements The Nuclear Regulatory Commission requires NSP-Minnesota to maintain a portfolio of investments to fund the costs of decommissioning its nuclear generating plants. Assets of the nuclear decommissioning fund are legally restricted for the purpose of decommissioning these facilities. The fund contains cash equivalents, debt securities, equity securities and other investments. NSP-Minnesota uses the MPUC approved asset allocation for the investment targets by asset class for the qualified trust. NSP-Minnesota recognizes the costs of funding the decommissioning over the lives of the nuclear plants, assuming rate recovery of all costs. Realized and unrealized gains on fund investments over the life of the fund are deferred as an offset of NSP-Minnesota’s regulatory asset for nuclear decommissioning costs. Consequently, any realized and unrealized gains and losses on securities in the nuclear decommissioning fund are deferred as a component of the associated nuclear decommissioning costs. Unrealized gains for the nuclear decommissioning fund were $1.3 billion and $1.2 billion as of June 30, 2024 and Dec. 31, 2023, and unrealized losses were $40 million and $29 million as of June 30, 2024 and Dec. 31, 2023, respectively. Non-derivative instruments with recurring fair value measurements in the nuclear decommissioning fund: June 30, 2024 Fair Value (Millions of Dollars) Cost Level 1 Level 2 Level 3 NAV Total Nuclear decommissioning fund (a) Cash equivalents $ 43 $ 43 $ — $ — $ — $ 43 Commingled funds 713 — — — 1,036 1,036 Debt securities 834 — 801 14 — 815 Equity securities 517 1,493 1 — — 1,494 Total $ 2,107 $ 1,536 $ 802 $ 14 $ 1,036 $ 3,388 (a) Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $55 million of other investments, including the rabbi trust. Dec. 31, 2023 Fair Value (Millions of Dollars) Cost Level 1 Level 2 Level 3 NAV Total Nuclear decommissioning fund (a) Cash equivalents $ 41 $ 41 $ — $ — $ — $ 41 Commingled funds 721 — — — 1,049 1,049 Debt securities 784 — 771 9 — 780 Equity securities 508 1,339 2 — — 1,341 Total $ 2,054 $ 1,380 $ 773 $ 9 $ 1,049 $ 3,211 (a) Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $51 million of other investments, including the rabbi trust. For the three and six months ended June 30, 2024 and 2023, there were no transfers of Level 3 investments between levels. Contractual maturity dates of debt securities in the nuclear decommissioning fund as of June 30, 2024: Final Contractual Maturity (Millions of Dollars) Due in 1 Year or Less Due in 1 to 5 Years Due in 5 to 10 Years Due after 10 Years Total Debt securities $ 5 $ 289 $ 266 $ 255 $ 815 Derivative Activities and Fair Value Measurements NSP-Minnesota enters into derivative instruments, including forward contracts, futures, swaps and options, for trading purposes and to manage risk in connection with changes in interest rates and utility commodity prices. Interest Rate Derivatives — NSP-Minnesota 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 income. As of June 30, 2024, 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 June 30, 2024, NSP-Minnesota had no unsettled interest rate derivatives. See Note 10 for the financial impact of qualifying interest rate cash flow hedges on NSP-Minnesota’s accumulated other comprehensive loss included in the consolidated statements of common stockholder’s equity and in the consolidated statements of comprehensive income. Wholesale and Commodity Trading — NSP-Minnesota conducts various wholesale and commodity trading activities, including the purchase and sale of electric capacity, energy, energy-related instruments and natural gas-related instruments, including derivatives. NSP-Minnesota 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 consolidated 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 and natural gas 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 — NSP-Minnesota enters into derivative instruments to manage variability of future cash flows from changes in commodity prices in its electric and natural gas operations. This could include the purchase or sale of energy or energy-related products, natural gas to generate electric energy, natural gas for resale and FTRs. The most significant derivative positions outstanding at June 30, 2024 for this purpose relate to FTR instruments administered by MISO. These instruments are intended to offset the impacts of transmission system congestion. When NSP-Minnesota enters into derivative instruments that mitigate commodity price risk on behalf of electric and natural gas 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. As of June 30, 2024, NSP-Minnesota had no commodity contracts designated as cash flow hedges. Gross notional amounts of commodity forwards, options and FTRs: (Amounts in Millions) (a)(b) June 30, 2024 Dec. 31, 2023 Megawatt hours of electricity 58 38 Million British thermal units of natural gas 62 64 (a) Not reflective of net positions in the underlying commodities. (b) Notional amounts for options included on a gross basis but weighted for the probability of exercise. Consideration of Credit Risk and Concentrations — NSP-Minnesota 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 consolidated balance sheets. NSP-Minnesota’s most significant concentrations of credit risk with particular entities or industries are contracts with counterparties to its wholesale, trading and non-trading commodity activities. As of June 30, 2024, three of NSP-Minnesota’s ten most significant counterparties for these activities, comprising $21 million, or 19%, of this credit exposure, had investment grade credit ratings from S&P Global Ratings, Moody’s Investor Services or Fitch Ratings. Three of the ten most significant counterparties, comprising $25 million, or 23%, of this credit exposure, were not rated by these external ratings agencies, but based on NSP-Minnesota’s internal analysis, had credit quality consistent with investment grade. Four of these significant counterparties, comprising $61 million or 56% of this credit exposure, had credit quality less than investment grade, based on internal analysis. Four of these significant counterparties are municipal or cooperative electric entities, RTOs or other utilities. Credit Related Contingent Features — Contract provisions for derivative instruments that NSP-Minnesota enters into, including those accounted for as normal purchase and normal sale contracts and therefore not reflected on the consolidated balance sheets, may require the posting of collateral or settlement of the contracts for various reasons, including if the applicable utility subsidiary’s credit ratings are downgraded below its investment grade credit rating by any of the major credit rating agencies. As of June 30, 2024 and Dec. 31, 2023, there were $17 million and $12 million, respectively, of derivative liabilities with such underlying contract provisions. Certain contracts also contain cross default provisions that may require the posting of collateral or settlement of the contracts if there was a failure under other financing arrangements related to payment terms or other covenants. As of June 30, 2024 and Dec. 31, 2023, there were approximately $86 million and $80 million, respectively of derivative liabilities with such underlying contract provisions. Certain derivative instruments are also subject to contract provisions that contain adequate assurance clauses. These provisions allow counterparties to seek performance assurance, including cash collateral, in the event that a given utility subsidiary’s ability to fulfill its contractual obligations is reasonably expected to be impaired. NSP-Minnesota had no collateral posted related to adequate assurance clauses in derivative contracts as of June 30, 2024 and Dec. 31, 2023. Recurring Derivative Fair Value Measurements Impact of derivative activity: Pre-Tax Fair Value Gains (Losses) Recognized During the Period in: (Millions of Dollars) Accumulated Other Comprehensive Loss Regulatory Assets and Liabilities Three Months Ended June 30, 2024 Other derivative instruments: Electric commodity $ — $ — Natural gas commodity — — Total $ — $ — Six Months Ended June 30, 2024 Derivatives designated as cash flow hedges: Interest rate $ 16 $ — Total $ 16 $ — Other derivative instruments: Electric commodity $ — $ 1 Natural gas commodity — 3 Total $ — $ 4 Three Months Ended June 30, 2023 Derivatives designated as cash flow hedges: Interest rate $ 8 $ — Total $ 8 $ — Derivatives designated as cash flow hedges: Electric commodity $ — $ (11) Total $ — $ (11) Six Months Ended June 30, 2023 Derivatives designated as cash flow hedges: Interest rate $ 4 $ — Total $ 4 $ — Other derivative instruments: Electric commodity $ — $ (28) Natural gas commodity $ — $ 2 Total $ — $ (26) . Pre-Tax Losses Reclassified into Income During the Period from: Pre-Tax Gains (Losses) Recognized During the Period in Income (Millions of Dollars) Regulatory Assets and Liabilities Three Months Ended June 30, 2024 Other derivative instruments: Commodity trading $ — $ (14) (a) Electric commodity 2 (b) — Total $ 2 $ (14) Six Months Ended June 30, 2024 Other derivative instruments: Commodity trading $ — $ (13) (a) Electric commodity 6 (b) — Natural gas commodity — (5) (c)(d) Total $ 6 $ (18) Three Months Ended June 30, 2023 Other derivative instruments: Electric commodity 7 (b) — Total $ 7 $ — Six Months Ended June 30, 2023 Other derivative instruments: Commodity trading $ — $ (1) (a) Electric commodity 21 (b) — Natural gas commodity — (5) (c)(d) Total $ 21 $ (6) (a) Recorded to electric revenues. Presented amounts do not reflect non-derivative transactions or margin sharing with customers. (b) 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. (c) Recorded to cost of natural gas sold and transported. These losses are subject to cost-recovery mechanisms and reclassified out of income to a regulatory asset, as appropriate. (d) Relates primarily to option premium amortization. NSP-Minnesota had no derivative instruments designated as fair value hedges during the six months ended June 30, 2024 and 2023. Derivative assets and liabilities measured at fair value on a recurring basis were as follows: June 30, 2024 Dec. 31, 2023 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: Commodity trading $ 5 $ 35 $ 22 $ 62 $ (44) $ 18 $ 7 $ 32 $ 32 $ 71 $ (42) $ 29 Electric commodity — — 65 65 (3) 62 — — 23 23 (7) 16 Natural gas commodity — 3 — 3 — 3 — 5 — 5 — 5 Total current derivative assets $ 5 $ 38 $ 87 $ 130 $ (47) $ 83 $ 7 $ 37 $ 55 $ 99 $ (49) $ 50 Noncurrent derivative assets Other derivative instruments: Commodity trading $ 5 $ 46 $ 57 $ 108 $ (35) $ 73 $ 7 $ 43 $ 45 $ 95 $ (34) $ 61 Total noncurrent derivative assets $ 5 $ 46 $ 57 $ 108 $ (35) $ 73 $ 7 $ 43 $ 45 $ 95 $ (34) $ 61 June 30, 2024 Dec. 31, 2023 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 liabilities Derivatives designated as cash flow hedges: Interest rate $ — $ — $ — $ — $ — $ — $ — $ 7 $ — $ 7 $ — $ 7 Other derivative instruments: Commodity trading $ 6 $ 65 $ 6 $ 77 $ (45) $ 32 $ 6 $ 60 $ 5 $ 71 $ (43) $ 28 Electric commodity — — 3 3 (3) — — — 7 7 (7) — Natural gas commodity — — — — — — — 3 — 3 — 3 Total current derivative liabilities $ 6 $ 65 $ 9 $ 80 $ (48) 32 $ 6 $ 70 $ 12 $ 88 $ (50) 38 PPAs (b) 6 6 Current derivative instruments $ 38 $ 44 Noncurrent derivative liabilities Other derivative instruments: Commodity trading $ 11 $ 56 $ 42 $ 109 $ (37) $ 72 $ 14 $ 49 $ 37 $ 100 $ (36) $ 64 Total noncurrent derivative liabilities $ 11 $ 56 $ 42 $ 109 $ (37) 72 $ 14 $ 49 $ 37 $ 100 $ (36) 64 PPAs (b) 19 22 Noncurrent derivative instruments $ 91 $ 86 (a) NSP-Minnesota nets derivative instruments and related collateral on its consolidated balance sheets when supported by a legally enforceable master netting agreement. At June 30, 2024 and Dec. 31, 2023, derivative assets and liabilities include no obligations to return cash collateral. At both June 30, 2024 and Dec. 31, 2023 derivative assets and liabilities include rights to reclaim cash collateral of $3 million. Counterparty netting amounts presented exclude settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements. (b) NSP-Minnesota 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 June 30 (Millions of Dollars) 2024 2023 Balance at April 1 $ 39 $ 46 Purchases (a) 72 97 Settlements (a) (27) (15) Net transactions recorded during the period: Gains recognized in earnings (b) 3 12 Net gains (losses) recognized as regulatory assets and liabilities (a) 6 (23) Balance at June 30 $ 93 $ 117 Six Months Ended June 30 (Millions of Dollars) 2024 2023 Balance at Jan. 1 $ 51 $ 107 Purchases (a) 72 97 Settlements (a) (42) (28) Net transactions recorded during the period: Gains (losses) recognized in earnings (b) 3 (2) Net gains (losses) recognized as regulatory assets and liabilities (a) 9 (57) Balance at June 30 $ 93 $ 117 (a) Relates primarily to FTR instruments administered by MISO. (b) Relates to commodity trading and is subject to substantial offsetting losses and gains on derivative instruments categorized as levels 1 and 2 in the consolidated income statement. See above tables for the income statement impact of derivative activity, including commodity trading gains and losses. Fair Value of Long-Term Debt As of June 30, 2024, other financial instruments for which the carrying amount did not equal fair value: June 30, 2024 Dec. 31, 2023 (Millions of Dollars) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt, including current portion $ 8,020 $ 6,847 $ 7,330 $ 6,561 Fair value of NSP-Minnesota’s long-term debt is estimated based on recent trades and observable spreads from benchmark interest rates for similar securities. Fair value estimates are based on information available to management as of June 30, 2024 and Dec. 31, 2023, and given the observability of the inputs, fair values presented for long-term debt were assigned as Level 2.

Benefit Plans and Other Postret

Benefit Plans and Other Postretirement Benefits	6 Months Ended
Benefit Plans and Other Postretirement Benefits	Jun. 30, 2024
Retirement Benefits [Abstract]
Benefit Plans and Other Postretirement Benefits	Components of Net Periodic Benefit Cost Three Months Ended June 30 2024 2023 2024 2023 (Millions of Dollars) Pension Benefits Postretirement Health Service cost $ 6 $ 5 $ — $ — Interest cost (a) 8 9 — 1 Expected return on plan assets (a) (12) (11) — — Amortization of net loss (a) 3 3 — — Settlement charge (b) 31 — — — Net periodic benefit cost 36 6 — 1 Effects of regulation (32) 3 — — Net benefit cost recognized for financial reporting $ 4 $ 9 $ — $ 1 Six Months Ended June 30 2024 2023 2024 2023 (Millions of Dollars) Pension Benefits Postretirement Health Service cost $ 11 $ 10 $ — $ — Interest cost (a) 17 18 1 1 Expected return on plan assets (a) (23) (23) — — Amortization of net loss (a) 6 6 — — Settlement charge (b) 31 — — — Net periodic benefit cost 42 11 1 1 Effects of regulation (29) 5 — — Net benefit cost recognized for financial reporting $ 13 $ 16 $ 1 $ 1 (a) The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the consolidated statements of income or capitalized on the consolidated balance sheets as a regulatory asset. (b) A settlement charge is required when the amount of lump-sum distributions during the year is greater than the sum of the service and interest cost components of the annual net periodic pension cost. In the second quarter of 2024, as a result of lump-sum distributions during the 2024 plan year, NSP-Minnesota recorded a pension settlement charge of $31 million, which was not recognized in earnings due to the effects of rate making. In January 2024, contributions totaling $100 million were made across Xcel Energy’s pension plans, of which $41 million was attributable to NSP-Minnesota. Xcel Energy does not expect additional pension contributions during 2024.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Legal NSP-Minnesota 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 NSP-Minnesota’s consolidated financial statements. Legal fees are generally expensed as incurred. Rate Matters and Other NSP-Minnesota 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 consolidated financial statements. Sherco — In 2018, NSP-Minnesota and SMMPA (Co-owner of Sherco Unit 3) reached a settlement with GE related to a 2011 incident, which damaged the turbine at Sherco Unit 3 and resulted in an extended outage. NSP-Minnesota notified the MPUC of its proposal to refund settlement proceeds to customers through the fuel clause adjustment. In March 2019, the MPUC approved NSP-Minnesota’s settlement refund proposal. Additionally, the MPUC decided to withhold any decision as to NSP-Minnesota’s prudence in connection with the incident at Sherco Unit 3 until after conclusion of an appeal pending between GE and NSP-Minnesota’s insurers. In February 2020, the Minnesota Court of Appeals affirmed the district court’s judgment in favor of GE. In January 2021, the OAG and DOC recommended that NSP-Minnesota refund approximately $17 million of replacement power costs previously recovered through the FCA. NSP-Minnesota responded that it acted prudently in connection with the Sherco Unit 3 outage, the MPUC has previously disallowed $22 million of related costs and no additional refund or disallowance is appropriate. In July 2022, the MPUC referred the matter to the Office of Administrative Hearings to conduct a contested case on the prudence of the replacement power costs incurred by NSP-Minnesota. In 2023, NSP-Minnesota and various parties filed recommendations, including the DOC which recommended a $56 million customer refund. The Xcel Large Industrial customer group recommended a refund of $72 million. In May 2024, the ALJ recommended a customer refund of $34 million (less a portion of the proceeds received from the settlement with GE). The ALJ indicated that consideration of the $22 million of previously disallowed costs was not in the scope of their recommendation. Xcel Energy has recorded an estimate for a customer refund in this matter. A final decision by the MPUC is expected in late 2024. Minnesota 2023 Fuel Clause Adjustment — In March 2024, NSP-Minnesota filed its annual fuel clause adjustment true-up petition to the MPUC, with a proposed refund of $126 million for fuel over-recoveries in 2023. In April 2024, the DOC recommended the MPUC approve the non-nuclear aspects of the petition. In May 2024, the DOC and Minnesota OAG filed comments relating to an outage at the Prairie Island generating station that lasted from October 2023 through February 2024. The DOC recommended that NSP-Minnesota refund $20 million of replacement power costs for 2023 as well as a future refund of replacement power costs for 2024 once those costs are known. The OAG recommended that NSP-Minnesota refund $18 million of replacement power costs for 2023 and did not address 2024. In July 2024, NSP-Minnesota filed reply comments in the 2023 proceeding in support of its position that no customer refund for replacement power costs is warranted. A final decision by the MPUC is expected in late 2024. Environmental New and changing federal and state environmental mandates can create financial obligations for NSP-Minnesota, which are normally recovered through the regulated rate process. Site Remediation Various federal and state environmental laws impose liability where hazardous substances or other regulated materials have been released to the environment. NSP-Minnesota may sometimes pay all or a portion of the cost to remediate sites where past activities of their predecessors or other parties have caused environmental contamination. Environmental contingencies could arise from various situations, including sites of former MGPs; and third-party sites, such as landfills, for which NSP-Minnesota is alleged to have sent wastes to that site. MGP, Landfill and Disposal Sites NSP-Minnesota is investigating, remediating or performing post-closure actions at seven MGP, landfill or other disposal sites across its service territories. NSP-Minnesota has recognized approximately $1 million of costs/liabilities for resolution of these issues; however, the final outcomes and timing are unknown. In addition, there may be regulatory recovery, insurance recovery and/or recovery from other potentially responsible parties, offsetting a portion of costs incurred. Water and Waste Coal Ash Regulation — NSP-Minnesota is subject to the CCR Rule, which imposes requirements for handling, storage, treatment and disposal of coal ash and other solid waste. In May 2024, final amendments to the CCR Rule were published. These include legacy CCR surface impoundments at inactive facilities and previously exempt areas where CCR was placed directly on land at CCR-regulated facilities, including areas of beneficial use. As a specific requirement of the CCR Rule, utilities must complete facility evaluations and groundwater sampling around their subject landfills, surface impoundments and certain other areas where coal ash was placed on land, as well as perform corrective actions where offsite groundwater has been impacted. If certain impacts to groundwater are detected, utilities may be required to perform additional groundwater investigations and/or perform corrective actions, typically beginning with an Assessment of Corrective Measures. NSP-Minnesota expects to incur $6 million for investigations through 2028 to perform required reporting and assess whether corrective actions are necessary. Asset retirement obligations have been recorded for each of these activities, and amounts are expected to be recoverable through regulatory mechanisms. NSP-Minnesota has also identified coal ash that is expected to be required to be removed from certain closed coal-fueled generating facilities at estimated costs totaling approximately $60 million. Asset retirement obligations have been recorded, with the costs expected to be recoverable through regulatory mechanisms. NSP-Minnesota continues to evaluate the 2024 updates to the CCR rule, the interpretations of those updates and how they will apply to specific sites. Assessment of the recent updates to the CCR Rule and corresponding site investigation activities may result in updates to estimated costs as well as identification of additional required corrective actions. Clean Water Act Section 316(b) — The Federal Clean Water Act requires the EPA to regulate cooling water intake structures to assure they reflect the best technology available for minimizing impingement and entrainment of aquatic species. NSP-Minnesota estimates capital expenditures of approximately $45 million may be required to comply with the requirements. NSP-Minnesota anticipates these costs will be recoverable through regulatory mechanisms. Air Clean Air Act NOx Allowance Allocations — In June 2023, the EPA published final regulations for ozone under the “Good Neighbor” provisions of the Clean Air Act. The final rule applies to generation facilities in Minnesota, as well as other states outside of our service territory. The rule establishes an allowance trading program for NOx that will impact NSP-Minnesota fossil fuel-fired electric generating facilities. Subject facilities will have to secure additional allowances, install NOx controls and/or develop a strategy of operations that utilizes the existing allowance allocations. Guidelines are also established for allowance banking and emission limit backstops. While the financial impacts of the final rule are uncertain and dependent on market forces and anticipated generation, NSP-Minnesota anticipates the annual costs could be significant, but would be recoverable through regulatory mechanisms. NSP-Minnesota has joined other companies in litigation challenging the EPA’s disapproval of Minnesota’s state implementation plan. Currently, the regulation is under a judicial stay for Minnesota. The regulation may become applicable in the future, depending on the outcome of the litigation and the status of the stay of the final rule, which was granted by the U.S. Supreme Court in June 2024. Leases NSP-Minnesota evaluates contracts that may contain leases, including PPAs and arrangements for the use of office space, land for solar developments 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 June 30 (Millions of Dollars) 2024 2023 Operating leases PPA capacity payments $ 25 $ 24 Other operating leases (a) 3 5 Total operating lease expense (b) $ 28 $ 29 (a) Includes immaterial short-term lease expense for both 2024 and 2023 . (b) PPA capacity payments are included in electric fuel and purchased power on the consolidated statements of income. Expense for other operating leases is included in O&M expense and electric fuel and purchased power. Six Months Ended June 30 (Millions of Dollars) 2024 2023 Operating leases PPA capacity payments $ 48 $ 49 Other operating leases (a) 8 9 Total operating lease expense (b) $ 56 $ 58 (a) Includes immaterial short-term lease expense for both 2024 and 2023 . (b) PPA capacity payments are included in electric fuel and purchased power on the consolidated statements of income. Expense for other operating leases is included in O&M expense and electric fuel and purchased power. Commitments under operating leases as of June 30, 2024: (Millions of Dollars) PPA Operating Other Operating Leases Total Leases Total minimum obligation $ 352 $ 262 $ 614 Interest component of obligation (29) (128) (157) Present value of minimum obligation $ 323 $ 134 457 Less current portion (94) Noncurrent operating lease liabilities $ 363 Variable Interest Entities Under certain PPAs, NSP-Minnesota purchases power from IPPs for which NSP-Minnesota is required to reimburse fuel costs, or to participate in tolling arrangements under which NSP-Minnesota procures the natural gas required to produce the energy that it purchases. NSP-Minnesota has determined that certain IPPs are VIEs, however NSP-Minnesota is not subject to risk of loss from the operations of these entities, and no significant financial support is required other than contractual payments for energy and capacity. NSP-Minnesota evaluated each of these VIEs for possible consolidation, including review of qualitative factors such as the length and terms of the contract, control over O&M, control over dispatch of electricity, historical and estimated future fuel and electricity prices and financing activities. NSP-Minnesota concluded that these entities are not required to be consolidated in its consolidated financial statements because NSP-Minnesota does not have the power to direct the activities that most significantly impact the entities’ economic performance. NSP-Minnesota had approximately 1,347 MW of capacity under long-term PPAs at both June 30, 2024 and Dec. 31, 2023, with entities that have been determined to be VIEs. These agreements have expiration dates through 2039.

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	6 Months Ended
Other Comprehensive Income (Loss)	Jun. 30, 2024
Stockholders' Equity Note [Abstract]
Other Comprehensive Income (Loss)	Changes in accumulated other comprehensive loss, net of tax: Three Months Ended June 30, 2024 Three Months Ended June 30, 2023 (Millions of Dollars) Gains and Losses on Cash Flow Hedges Defined Benefit Pension and Postretirement Items Total Gains and Losses on Cash Flow Hedges Defined Benefit Pension and Postretirement Items Total Accumulated other comprehensive loss at April 1 $ (6) $ (2) $ (8) $ (19) $ (2) $ (21) Gains reclassified from net accumulated other comprehensive income: Other comprehensive gain before reclassifications — — — 6 — 6 Net current period other comprehensive income — — — 6 — 6 Accumulated other comprehensive loss at June 30 $ (6) $ (2) $ (8) $ (13) $ (2) $ (15) Six Months Ended June 30, 2024 Six Months Ended June 30, 2023 (Millions of Dollars) Gains and Losses on Cash Flow Hedges Defined Benefit Pension and Postretirement Items Total Gains and Losses on Cash Flow Hedges Defined Benefit Pension and Postretirement Items Total Accumulated other comprehensive loss at Jan. 1 $ (18) $ (2) $ (20) $ (16) $ (2) $ (18) Gains reclassified from net accumulated other comprehensive income: Other comprehensive gain before reclassifications 12 — 12 3 — 3 Net current period other comprehensive income 12 — 12 3 — 3 Accumulated other comprehensive loss at June 30 $ (6) $ (2) $ (8) $ (13) $ (2) $ (15)

Segment Information

Segment Information	6 Months Ended
Segment Information	Jun. 30, 2024
Segment Reporting [Abstract]
Segment Information	NSP-Minnesota evaluates performance based on profit or loss generated from the product or service provided. These segments are managed separately because the revenue streams are dependent upon regulated rate recovery, which is separately determined for each segment. NSP-Minnesota has the following reportable segments: • Regulated Electric — The regulated electric utility segment generates electricity which is transmitted and distributed in Minnesota, North Dakota and South Dakota. In addition, this segment includes sales for resale and provides wholesale transmission service to various entities in the United States. The regulated electric utility segment also includes NSP-Minnesota’s wholesale commodity and trading operations. • Regulated Natural Gas — The regulated natural gas utility segment transports, stores and distributes natural gas in portions of Minnesota and North Dakota. NSP-Minnesota also presents All Other, which includes operating segments with revenues below the necessary quantitative thresholds. Those operating segments primarily include appliance repair services revenues/commissions, non-utility real estate activities and revenues associated with processing solid waste into refuse-derived fuel. Asset and capital expenditure information is not provided for NSP-Minnesota’s reportable segments. As an integrated electric and natural gas utility, NSP-Minnesota operates significant assets that are not dedicated to a specific business segment. Reporting assets and capital expenditures by business segment would require arbitrary and potentially misleading allocations, which may not necessarily reflect the assets that would be required for the operation of the business segments on a stand-alone basis. Certain costs, such as common depreciation, common O&M expenses and interest expense are allocated based on cost causation allocators across each segment. In addition, a general allocator is used for certain general and administrative expenses, including office supplies, rent, property insurance and general advertising. NSP-Minnesota’s segment information: Three Months Ended June 30 (Millions of Dollars) 2024 2023 Regulated Electric Total revenues (a) $ 1,237 $ 1,189 Net income 122 134 Regulated Natural Gas Total revenues (b) $ 90 $ 98 Net income (loss) 4 (9) All Other Total revenues $ 3 $ 12 Net income 5 2 Consolidated Total Total revenues (a)(b) $ 1,330 $ 1,299 Net income 131 127 (a) Total revenues include $120 million and $113 million of affiliate electric revenue for the three months ended June 30, 2024 and 2023. (b) Total revenues include an immaterial amount of affiliate gas revenue for the three months ended June 30, 2024 and 2023. Six Months Ended June 30 (Millions of Dollars) 2024 2023 Regulated Electric Total revenues (a) $ 2,492 $ 2,445 Net income 267 245 Regulated Natural Gas Operating revenues (b) $ 363 $ 498 Intersegment revenue 1 1 Total revenues $ 364 $ 499 Net income 55 21 All Other Total revenues $ 11 $ 22 Net income 20 — Consolidated Total Total revenues $ 2,867 $ 2,966 Reconciling eliminations (1) (1) Total operating revenues (a)(b) $ 2,866 $ 2,965 Net income 342 266 (a) Total revenues include $242 million and $238 million of affiliate electric revenue for the six months ended June 30, 2024 and 2023. (b) Operating revenues include an immaterial amount of affiliate gas revenue for the six months ended June 30, 2024 and 2023.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Millions	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pay vs Performance Disclosure
Net income	$ 131	$ 127	$ 342	$ 266

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Jun. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Selected Balance Sheet Data (Ta

Selected Balance Sheet Data (Tables)	6 Months Ended
Selected Balance Sheet Data (Tables)	Jun. 30, 2024
Balance Sheet Related Disclosures [Abstract]
Accounts Receivable, Net	(Millions of Dollars) June 30, 2024 Dec. 31, 2023 Accounts receivable, net Accounts receivable $ 501 $ 538 Less allowance for bad debts (39) (48) Accounts receivable, net $ 462 $ 490
Inventories	(Millions of Dollars) June 30, 2024 Dec. 31, 2023 Inventories Materials and supplies $ 226 $ 219 Fuel 98 105 Natural gas 10 32 Total inventories $ 334 $ 356
Property, plant and equipment, net	(Millions of Dollars) June 30, 2024 Dec. 31, 2023 Property, plant and equipment, net Electric plant $ 21,780 $ 21,206 Natural gas plant 2,312 2,256 Common and other property 1,346 1,301 Plant to be retired (a) 575 604 Construction work in progress 1,607 1,085 Total property, plant and equipment 27,620 26,452 Less accumulated depreciation (8,451) (8,044) Nuclear fuel 3,444 3,337 Less accumulated amortization (3,041) (2,988) Property, plant and equipment, net $ 19,572 $ 18,757 (a) Amounts include Sherco 1 and 3 and A.S. King. Balance is presented net of accumulated depreciation.

Borrowings and Other Financin_2

Borrowings and Other Financing Instruments (Tables)	6 Months Ended
Borrowings and Other Financing Instruments (Tables)	Jun. 30, 2024
Borrowings and Other Financing Instruments [Abstract]
Credit Facilities	At June 30, 2024, NSP-Minnesota had the following committed revolving credit facility available (in millions of dollars): Credit Facility (a) Drawn (b) Available $ 700 $ 12 $ 688 (a) Expires in September 2027. (b) Includes outstanding commercial paper and 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 June 30, 2024 Year Ended Dec. 31, 2023 Borrowing limit $ 250 $ 250 Amount outstanding at period end — — Average amount outstanding — 17 Maximum amount outstanding N/A 135 Weighted average interest rate, computed on a daily basis N/A 4.97 % Weighted average interest rate at period end N/A 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 June 30, 2024 Year Ended Dec. 31, 2023 Borrowing limit $ 700 $ 700 Amount outstanding at period end — 165 Average amount outstanding — 92 Maximum amount outstanding N/A 441 Weighted average interest rate, computed on a daily basis N/A 4.99 % Weighted average interest rate at period end N/A 5.47

Revenues (Tables)

Revenues (Tables)	6 Months Ended
Revenues (Tables)	Jun. 30, 2024
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	NSP-Minnesota’s operating revenues consisted of the following: Three Months Ended June 30, 2024 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 350 $ 37 $ — $ 387 C&I 571 25 — 596 Other 10 — 3 13 Total retail 931 62 3 996 Wholesale 57 — — 57 Transmission 56 — — 56 Interchange and other 115 11 — 126 Total revenue from contracts with customers 1,159 73 3 1,235 Alternative revenue and other 78 17 — 95 Total revenues $ 1,237 $ 90 $ 3 $ 1,330 Three Months Ended June 30, 2023 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 317 $ 42 $ 10 $ 369 C&I 517 40 — 557 Other 9 — 2 11 Total retail 843 82 12 937 Wholesale 80 — — 80 Transmission 66 — — 66 Interchange and other 108 3 — 111 Total revenue from contracts with customers 1,097 85 12 1,194 Alternative revenue and other 92 13 — 105 Total revenues $ 1,189 $ 98 $ 12 $ 1,299 Six Months Ended June 30, 2024 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 718 $ 175 $ 7 $ 900 C&I 1,093 115 — 1,208 Other 19 4 23 Total retail 1,830 290 11 2,131 Wholesale 132 — — 132 Transmission 119 — — 119 Interchange and other 240 28 — 268 Total revenue from contracts with customers 2,321 318 11 2,650 Alternative revenue and other 171 45 — 216 Total revenues $ 2,492 $ 363 $ 11 $ 2,866 Six Months Ended June 30, 2023 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 675 $ 249 $ 19 $ 943 C&I 1,060 213 — 1,273 Other 17 — 3 20 Total retail 1,752 462 22 2,236 Wholesale 184 — — 184 Transmission 130 — — 130 Interchange and other 234 5 — 239 Total revenue from contracts with customers 2,300 467 22 2,789 Alternative revenue and other 145 31 — 176 Total revenues $ 2,445 $ 498 $ 22 $ 2,965

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
Income Taxes (Tables)	Jun. 30, 2024
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	Reconciliation between the statutory rate and ETR: Six Months Ended June 30 2024 2023 Federal statutory rate 21.0 % 21.0 % State tax (net of federal tax effect) 7.0 7.0 (Decreases) increases: Wind PTCs (a) (49.9) (74.7) Plant regulatory differences (b) (5.4) (6.7) Other tax credits, net operating loss & tax credit allowances (1.1) (1.5) Other, net 0.8 2.0 Effective income tax rate (27.6) % (52.9) % (a) Wind PTCs net of estimated transfer discounts are credited to customers (reduction to revenue) and do not materially impact net income. (b) Plant regulatory differences primarily relate to the credit of excess deferred taxes to customers. Income tax benefits associated with the credit are offset by corresponding revenue reductions.

Fair Value of Financial Asset_2

Fair Value of Financial Assets and Liabilities (Tables)	3 Months Ended	6 Months Ended
Fair Value of Financial Assets and Liabilities (Tables)	Jun. 30, 2024	Jun. 30, 2024
Fair Value Disclosures [Abstract]
Final Contractual Maturity Dates of Debt Securities in the Nuclear Decommissioning Fund by Asset Class		Contractual maturity dates of debt securities in the nuclear decommissioning fund as of June 30, 2024: Final Contractual Maturity (Millions of Dollars) Due in 1 Year or Less Due in 1 to 5 Years Due in 5 to 10 Years Due after 10 Years Total Debt securities $ 5 $ 289 $ 266 $ 255 $ 815
Gross Notional Amounts of Commodity Forwards, Options, and FTRs		Gross notional amounts of commodity forwards, options and FTRs: (Amounts in Millions) (a)(b) June 30, 2024 Dec. 31, 2023 Megawatt hours of electricity 58 38 Million British thermal units of natural gas 62 64 (a) Not reflective of net positions in the underlying commodities. (b) Notional amounts for options included on a gross basis but weighted for the probability of exercise.
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income		Impact of derivative activity: Pre-Tax Fair Value Gains (Losses) Recognized During the Period in: (Millions of Dollars) Accumulated Other Comprehensive Loss Regulatory Assets and Liabilities Three Months Ended June 30, 2024 Other derivative instruments: Electric commodity $ — $ — Natural gas commodity — — Total $ — $ — Six Months Ended June 30, 2024 Derivatives designated as cash flow hedges: Interest rate $ 16 $ — Total $ 16 $ — Other derivative instruments: Electric commodity $ — $ 1 Natural gas commodity — 3 Total $ — $ 4 Three Months Ended June 30, 2023 Derivatives designated as cash flow hedges: Interest rate $ 8 $ — Total $ 8 $ — Derivatives designated as cash flow hedges: Electric commodity $ — $ (11) Total $ — $ (11) Six Months Ended June 30, 2023 Derivatives designated as cash flow hedges: Interest rate $ 4 $ — Total $ 4 $ — Other derivative instruments: Electric commodity $ — $ (28) Natural gas commodity $ — $ 2 Total $ — $ (26) . Pre-Tax Losses Reclassified into Income During the Period from: Pre-Tax Gains (Losses) Recognized During the Period in Income (Millions of Dollars) Regulatory Assets and Liabilities Three Months Ended June 30, 2024 Other derivative instruments: Commodity trading $ — $ (14) (a) Electric commodity 2 (b) — Total $ 2 $ (14) Six Months Ended June 30, 2024 Other derivative instruments: Commodity trading $ — $ (13) (a) Electric commodity 6 (b) — Natural gas commodity — (5) (c)(d) Total $ 6 $ (18) Three Months Ended June 30, 2023 Other derivative instruments: Electric commodity 7 (b) — Total $ 7 $ — Six Months Ended June 30, 2023 Other derivative instruments: Commodity trading $ — $ (1) (a) Electric commodity 21 (b) — Natural gas commodity — (5) (c)(d) Total $ 21 $ (6) (a) Recorded to electric revenues. Presented amounts do not reflect non-derivative transactions or margin sharing with customers. (b) 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. (c) Recorded to cost of natural gas sold and transported. These losses are subject to cost-recovery mechanisms and reclassified out of income to a regulatory asset, as appropriate. (d) Relates primarily to option premium amortization.
Derivative Assets and Liabilities Measured at Fair Value on a Recurring Basis by Hierarchy Level		June 30, 2024 Dec. 31, 2023 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: Commodity trading $ 5 $ 35 $ 22 $ 62 $ (44) $ 18 $ 7 $ 32 $ 32 $ 71 $ (42) $ 29 Electric commodity — — 65 65 (3) 62 — — 23 23 (7) 16 Natural gas commodity — 3 — 3 — 3 — 5 — 5 — 5 Total current derivative assets $ 5 $ 38 $ 87 $ 130 $ (47) $ 83 $ 7 $ 37 $ 55 $ 99 $ (49) $ 50 Noncurrent derivative assets Other derivative instruments: Commodity trading $ 5 $ 46 $ 57 $ 108 $ (35) $ 73 $ 7 $ 43 $ 45 $ 95 $ (34) $ 61 Total noncurrent derivative assets $ 5 $ 46 $ 57 $ 108 $ (35) $ 73 $ 7 $ 43 $ 45 $ 95 $ (34) $ 61 June 30, 2024 Dec. 31, 2023 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 liabilities Derivatives designated as cash flow hedges: Interest rate $ — $ — $ — $ — $ — $ — $ — $ 7 $ — $ 7 $ — $ 7 Other derivative instruments: Commodity trading $ 6 $ 65 $ 6 $ 77 $ (45) $ 32 $ 6 $ 60 $ 5 $ 71 $ (43) $ 28 Electric commodity — — 3 3 (3) — — — 7 7 (7) — Natural gas commodity — — — — — — — 3 — 3 — 3 Total current derivative liabilities $ 6 $ 65 $ 9 $ 80 $ (48) 32 $ 6 $ 70 $ 12 $ 88 $ (50) 38 PPAs (b) 6 6 Current derivative instruments $ 38 $ 44 Noncurrent derivative liabilities Other derivative instruments: Commodity trading $ 11 $ 56 $ 42 $ 109 $ (37) $ 72 $ 14 $ 49 $ 37 $ 100 $ (36) $ 64 Total noncurrent derivative liabilities $ 11 $ 56 $ 42 $ 109 $ (37) 72 $ 14 $ 49 $ 37 $ 100 $ (36) 64 PPAs (b) 19 22 Noncurrent derivative instruments $ 91 $ 86 (a) NSP-Minnesota nets derivative instruments and related collateral on its consolidated balance sheets when supported by a legally enforceable master netting agreement. At June 30, 2024 and Dec. 31, 2023, derivative assets and liabilities include no obligations to return cash collateral. At both June 30, 2024 and Dec. 31, 2023 derivative assets and liabilities include rights to reclaim cash collateral of $3 million. Counterparty netting amounts presented exclude settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements. (b) NSP-Minnesota 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		Changes in Level 3 commodity derivatives: Three Months Ended June 30 (Millions of Dollars) 2024 2023 Balance at April 1 $ 39 $ 46 Purchases (a) 72 97 Settlements (a) (27) (15) Net transactions recorded during the period: Gains recognized in earnings (b) 3 12 Net gains (losses) recognized as regulatory assets and liabilities (a) 6 (23) Balance at June 30 $ 93 $ 117 Six Months Ended June 30 (Millions of Dollars) 2024 2023 Balance at Jan. 1 $ 51 $ 107 Purchases (a) 72 97 Settlements (a) (42) (28) Net transactions recorded during the period: Gains (losses) recognized in earnings (b) 3 (2) Net gains (losses) recognized as regulatory assets and liabilities (a) 9 (57) Balance at June 30 $ 93 $ 117 (a) Relates primarily to FTR instruments administered by MISO. (b)
Carrying Amount and Fair Value of Long-term Debt		As of June 30, 2024, other financial instruments for which the carrying amount did not equal fair value: June 30, 2024 Dec. 31, 2023 (Millions of Dollars) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt, including current portion $ 8,020 $ 6,847 $ 7,330 $ 6,561
Cost and Fair Value of Nuclear Decommissioning Fund Investments	Non-derivative instruments with recurring fair value measurements in the nuclear decommissioning fund: June 30, 2024 Fair Value (Millions of Dollars) Cost Level 1 Level 2 Level 3 NAV Total Nuclear decommissioning fund (a) Cash equivalents $ 43 $ 43 $ — $ — $ — $ 43 Commingled funds 713 — — — 1,036 1,036 Debt securities 834 — 801 14 — 815 Equity securities 517 1,493 1 — — 1,494 Total $ 2,107 $ 1,536 $ 802 $ 14 $ 1,036 $ 3,388 (a) Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $55 million of other investments, including the rabbi trust.	Dec. 31, 2023 Fair Value (Millions of Dollars) Cost Level 1 Level 2 Level 3 NAV Total Nuclear decommissioning fund (a) Cash equivalents $ 41 $ 41 $ — $ — $ — $ 41 Commingled funds 721 — — — 1,049 1,049 Debt securities 784 — 771 9 — 780 Equity securities 508 1,339 2 — — 1,341 Total $ 2,054 $ 1,380 $ 773 $ 9 $ 1,049 $ 3,211 (a) Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $51 million of other investments, including the rabbi trust.

Benefit Plans and Other Postr_2

Benefit Plans and Other Postretirement Benefits (Tables)	6 Months Ended
	Jun. 30, 2024
Retirement Benefits [Abstract]
Components of Net Periodic Benefit Cost (Credit)	Components of Net Periodic Benefit Cost Three Months Ended June 30 2024 2023 2024 2023 (Millions of Dollars) Pension Benefits Postretirement Health Service cost $ 6 $ 5 $ — $ — Interest cost (a) 8 9 — 1 Expected return on plan assets (a) (12) (11) — — Amortization of net loss (a) 3 3 — — Settlement charge (b) 31 — — — Net periodic benefit cost 36 6 — 1 Effects of regulation (32) 3 — — Net benefit cost recognized for financial reporting $ 4 $ 9 $ — $ 1 Six Months Ended June 30 2024 2023 2024 2023 (Millions of Dollars) Pension Benefits Postretirement Health Service cost $ 11 $ 10 $ — $ — Interest cost (a) 17 18 1 1 Expected return on plan assets (a) (23) (23) — — Amortization of net loss (a) 6 6 — — Settlement charge (b) 31 — — — Net periodic benefit cost 42 11 1 1 Effects of regulation (29) 5 — — Net benefit cost recognized for financial reporting $ 13 $ 16 $ 1 $ 1 (a) The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the consolidated statements of income or capitalized on the consolidated balance sheets as a regulatory asset. (b) A settlement charge is required when the amount of lump-sum distributions during the year is greater than the sum of the service and interest cost components of the annual net periodic pension cost.	[1]

[1] The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the consolidated statements of income or capitalized on the consolidated balance sheets as a regulatory asset.

Commitment and Contingencies (T

Commitment and Contingencies (Tables)	3 Months Ended	6 Months Ended
Commitment and Contingencies (Tables)	Jun. 30, 2024	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Lease, Cost	Components of lease expense: Three Months Ended June 30 (Millions of Dollars) 2024 2023 Operating leases PPA capacity payments $ 25 $ 24 Other operating leases (a) 3 5 Total operating lease expense (b) $ 28 $ 29 (a) Includes immaterial short-term lease expense for both 2024 and 2023 . (b) PPA capacity payments are included in electric fuel and purchased power on the consolidated statements of income. Expense for other operating leases is included in O&M expense and electric fuel and purchased power. Six Months Ended June 30 (Millions of Dollars) 2024 2023 Operating leases PPA capacity payments $ 48 $ 49 Other operating leases (a) 8 9 Total operating lease expense (b) $ 56 $ 58 (a) Includes immaterial short-term lease expense for both 2024 and 2023 . (b)
Lessee, Operating Lease, Liability, Maturity		Commitments under operating leases as of June 30, 2024: (Millions of Dollars) PPA Operating Other Operating Leases Total Leases Total minimum obligation $ 352 $ 262 $ 614 Interest component of obligation (29) (128) (157) Present value of minimum obligation $ 323 $ 134 457 Less current portion (94) Noncurrent operating lease liabilities $ 363

Other Comprehensive Income (L_2

Other Comprehensive Income (Loss) (Tables)	6 Months Ended
Other Comprehensive Income (Loss) (Tables)	Jun. 30, 2024
Stockholders' Equity Note [Abstract]
Changes in Accumulated Other Comprehensive Income (Loss), Net of Tax	Changes in accumulated other comprehensive loss, net of tax: Three Months Ended June 30, 2024 Three Months Ended June 30, 2023 (Millions of Dollars) Gains and Losses on Cash Flow Hedges Defined Benefit Pension and Postretirement Items Total Gains and Losses on Cash Flow Hedges Defined Benefit Pension and Postretirement Items Total Accumulated other comprehensive loss at April 1 $ (6) $ (2) $ (8) $ (19) $ (2) $ (21) Gains reclassified from net accumulated other comprehensive income: Other comprehensive gain before reclassifications — — — 6 — 6 Net current period other comprehensive income — — — 6 — 6 Accumulated other comprehensive loss at June 30 $ (6) $ (2) $ (8) $ (13) $ (2) $ (15) Six Months Ended June 30, 2024 Six Months Ended June 30, 2023 (Millions of Dollars) Gains and Losses on Cash Flow Hedges Defined Benefit Pension and Postretirement Items Total Gains and Losses on Cash Flow Hedges Defined Benefit Pension and Postretirement Items Total Accumulated other comprehensive loss at Jan. 1 $ (18) $ (2) $ (20) $ (16) $ (2) $ (18) Gains reclassified from net accumulated other comprehensive income: Other comprehensive gain before reclassifications 12 — 12 3 — 3 Net current period other comprehensive income 12 — 12 3 — 3 Accumulated other comprehensive loss at June 30 $ (6) $ (2) $ (8) $ (13) $ (2) $ (15)

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
Segment Information (Tables)	Jun. 30, 2024
Segment Reporting [Abstract]
Results from Operations by Reportable Segment	NSP-Minnesota’s segment information: Three Months Ended June 30 (Millions of Dollars) 2024 2023 Regulated Electric Total revenues (a) $ 1,237 $ 1,189 Net income 122 134 Regulated Natural Gas Total revenues (b) $ 90 $ 98 Net income (loss) 4 (9) All Other Total revenues $ 3 $ 12 Net income 5 2 Consolidated Total Total revenues (a)(b) $ 1,330 $ 1,299 Net income 131 127 (a) Total revenues include $120 million and $113 million of affiliate electric revenue for the three months ended June 30, 2024 and 2023. (b) Total revenues include an immaterial amount of affiliate gas revenue for the three months ended June 30, 2024 and 2023. Six Months Ended June 30 (Millions of Dollars) 2024 2023 Regulated Electric Total revenues (a) $ 2,492 $ 2,445 Net income 267 245 Regulated Natural Gas Operating revenues (b) $ 363 $ 498 Intersegment revenue 1 1 Total revenues $ 364 $ 499 Net income 55 21 All Other Total revenues $ 11 $ 22 Net income 20 — Consolidated Total Total revenues $ 2,867 $ 2,966 Reconciling eliminations (1) (1) Total operating revenues (a)(b) $ 2,866 $ 2,965 Net income 342 266 (a) Total revenues include $242 million and $238 million of affiliate electric revenue for the six months ended June 30, 2024 and 2023. (b) Operating revenues include an immaterial amount of affiliate gas revenue for the six months ended June 30, 2024 and 2023.

Accounts Receivable (Details)

Accounts Receivable (Details) - Related Party - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Related Party Transaction [Line Items]
Accounts Receivable	$ 501	$ 538
Accounts Receivable, Allowance for Credit Loss, Current	39	48
Accounts receivable, net	$ 462	$ 490

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Public Utilities, Inventory [Line Items]
Inventories	$ 334	$ 356
Materials and supplies
Public Utilities, Inventory [Line Items]
Inventories	226	219
Fuel
Public Utilities, Inventory [Line Items]
Inventories	98	105
Natural Gas
Public Utilities, Inventory [Line Items]
Inventories	$ 10	$ 32

Property, Plant and Equipment (

Property, Plant and Equipment (Details) - USD ($) $ in Millions		Jun. 30, 2024	Dec. 31, 2023
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		$ 27,620	$ 26,452
Accumulated depreciation and amortization		(8,451)	(8,044)
Property, plant and equipment, net		19,572	18,757
Electric plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		21,780	21,206
Natural gas plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		2,312	2,256
Common and other property
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		1,346	1,301
Plant to be Retired (a)
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	[1]	575	604
Construction work in progress
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		1,607	1,085
Nuclear fuel
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		3,444	3,337
Accumulated depreciation and amortization		$ (3,041)	$ (2,988)

[1] Amounts include Sherco 1 and 3 and A.S. King. Balance is presented net of accumulated depreciation.

Money Pool (Details)

Money Pool (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Money Pool (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Short-term Debt [Line Items]
Amount outstanding at period end	$ 0	$ 165
Money Pool
Short-term Debt [Line Items]
Borrowing limit	250	250
Amount outstanding at period end	0	0
Average amount outstanding	$ 0	17
Maximum amount outstanding		$ 135
Weighted average interest rate, computed on a daily basis		4.97%

Borrowings and Other Financin_3

Borrowings and Other Financing Instruments Commercial Paper (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Short-term Debt [Line Items]
Amount outstanding at period end	$ 0	$ 165
Commercial Paper
Short-term Debt [Line Items]
Borrowing limit	700	700
Amount outstanding at period end	0	165
Average amount outstanding	$ 0	92
Maximum amount outstanding		$ 441
Weighted average interest rate, computed on a daily basis		4.99%
Weighted average interest rate at period end		5.47%

Letters of Credit (Details)

Letters of Credit (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Line of Credit Facility [Line Items]
Amount outstanding at period end	$ 0	$ 165
Letter of Credit
Line of Credit Facility [Line Items]
Amount outstanding at period end	$ 12	$ 15

Credit Facility (Details)

Credit Facility (Details) $ in Millions		6 Months Ended
Credit Facility (Details) $ in Millions		Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Line of Credit Facility [Line Items]
Amount outstanding at period end		$ 0	$ 165
Credit Facility
Line of Credit Facility [Line Items]
Borrowing limit	[1]	700
Amount outstanding at period end	[2]	$ 12
Number of extension you can request		2
Available		$ 688
Direct advances on the credit facility outstanding		0	0
Letter of Credit
Line of Credit Facility [Line Items]
Amount outstanding at period end		$ 12	$ 15

[1] Expires in September 2027. Includes outstanding commercial paper and letters of credit.

Bilateral Credit Agreement (Det

Bilateral Credit Agreement (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Short-term Debt [Line Items]
Amount outstanding at period end	$ 0	$ 165
Letter of Credit
Short-term Debt [Line Items]
Amount outstanding at period end	12	$ 15
Letter of Credit \| Bilateral Credit Agreement
Short-term Debt [Line Items]
Borrowing Limit	75
Amount outstanding at period end	$ 70
Letter of Credit \| Bilateral Credit Agreement \| NSP Minnesota [Member]
Short-term Debt [Line Items]
Debt Instrument, Term	1 year

Borrowings and Other Financin_4

Borrowings and Other Financing Instruments (Details) - Series Due March 15, 2054 - Bonds [Member] $ in Millions	Jun. 30, 2024 USD ($)
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 700
Debt Instrument, Interest Rate, Stated Percentage	5.40%

Revenues (Details)

Revenues (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Revenues (Details) - USD ($) $ in Millions	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,330	$ 1,299	$ 2,866	$ 2,965
Regulated Electric \| Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	1,237	1,189	2,492	2,445
Regulated Natural Gas \| Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	90	98	363	498
All Other \| Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	3	12	11	22
Retail
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	996	937	2,131	2,236
Retail \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	387	369	900	943
Retail \| C&I
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	596	557	1,208	1,273
Retail \| Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	13	11	23	20
Retail \| Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	931	843	1,830	1,752
Retail \| Regulated Electric \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	350	317	718	675
Retail \| Regulated Electric \| C&I
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	571	517	1,093	1,060
Retail \| Regulated Electric \| Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	10	9	19	17
Retail \| Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	62	82	290	462
Retail \| Regulated Natural Gas \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	37	42	175	249
Retail \| Regulated Natural Gas \| C&I
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	25	40	115	213
Retail \| Regulated Natural Gas \| Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0		0
Retail \| All Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	3	12	11	22
Retail \| All Other \| Residential
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	10	7	19
Retail \| All Other \| C&I
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Retail \| All Other \| Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	3	2	4	3
Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	57	80	132	184
Wholesale \| Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	57	80	132	184
Wholesale \| Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Wholesale \| All Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Transmission
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	56	66	119	130
Transmission \| Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	56	66	119	130
Transmission \| Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Transmission \| All Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Interchange
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	126	111	268	239
Interchange \| Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	115	108	240	234
Interchange \| Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	11	3	28	5
Interchange \| All Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,235	1,194	2,650	2,789
Total revenue from contracts with customers \| Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,159	1,097	2,321	2,300
Total revenue from contracts with customers \| Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	73	85	318	467
Total revenue from contracts with customers \| All Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	3	12	11	22
Alternative revenue and other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	95	105	216	176
Alternative revenue and other \| Regulated Electric
Disaggregation of Revenue [Line Items]
Alternative revenue and other	78	92	171	145
Alternative revenue and other \| Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Alternative revenue and other	17	13	45	31
Alternative revenue and other \| All Other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	$ 0	$ 0	$ 0	$ 0

Income Taxes (Details)

Income Taxes (Details)		6 Months Ended
Income Taxes (Details)		Jun. 30, 2024	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Federal statutory rate		21%	21%
State tax (net of federal tax effect)		7%	7%
Wind PTCs	[1]	(49.90%)	(74.70%)
Plant regulatory differences	[2]	(5.40%)	(6.70%)
Other tax credits, net operating loss & tax credit allowances		(1.10%)	(1.50%)
Other, net		0.80%	2%
Effective income tax rate		(27.60%)	(52.90%)

[1] Wind PTCs net of estimated transfer discounts are credited to customers (reduction to revenue) and do not materially impact net income. Plant regulatory differences primarily relate to the credit of excess deferred taxes to customers. Income tax benefits associated with the credit are offset by corresponding revenue reductions.

Non-Derivative Fair Value Measu

Non-Derivative Fair Value Measurements (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024		Jun. 30, 2023	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Miscellaneous investments	$ 55			$ 51
Debt Securities, Available-for-sale, Unrealized Gain	1,300		$ 1,200
Debt Securities, Available-for-sale, Unrealized Loss	40		$ 29
Final Contractual Maturity [Abstract]
Due in 1 Year or Less	5
Due in 1 to 5 Years	289
Due in 5 to 10 Years	266
Due after 10 Years	255
Total	815
Fair Value Measured on a Recurring Basis \| Cost
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	2,107	[1]		2,054	[2]
Fair Value Measured on a Recurring Basis \| Cost \| Cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	43	[1]		41	[2]
Fair Value Measured on a Recurring Basis \| Cost \| Commingled funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commingled funds	713	[1]		721	[2]
Fair Value Measured on a Recurring Basis \| Cost \| Debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities	834	[1]		784	[2]
Fair Value Measured on a Recurring Basis \| Cost \| Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	517	[1]		508	[2]
Fair Value Measured on a Recurring Basis \| Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	3,388	[1]		3,211	[2]
NAV	1,036	[1]		1,049	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	43	[1]		41	[2]
NAV	0	[1]		0	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Commingled funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commingled funds	1,036	[1]		1,049	[2]
NAV	1,036	[1]		1,049	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities	815	[1]		780	[2]
NAV	0	[1]		0	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	1,494	[1]		1,341	[2]
NAV	0	[1]		0	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	1,536	[1]		1,380	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 1 \| Cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	43	[1]		41	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 1 \| Commingled funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commingled funds	0	[1]		0	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 1 \| Debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities	0	[1]		0	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 1 \| Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	1,493	[1]		1,339	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	802	[1]		773	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 2 \| Cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	[1]		0	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 2 \| Commingled funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commingled funds	0	[1]		0	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 2 \| Debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities	801	[1]		771	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 2 \| Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	1	[1]		2	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	14	[1]		9	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 3 \| Cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	[1]		0	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 3 \| Commingled funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commingled funds	0	[1]		0	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 3 \| Debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities	14	[1]		9	[2]
Fair Value Measured on a Recurring Basis \| Fair Value \| Level 3 \| Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	$ 0	[1]		$ 0	[2]

[1] Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $55 million of other investments, including the rabbi trust. Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $51 million of other investments, including the rabbi trust.

Interest Rate Derivative (Detai

Interest Rate Derivative (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
Interest Rate Derivative (Details) - USD ($) $ in Millions		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Other Derivative Instruments
Interest Rate Derivatives [Abstract]
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		$ 2	$ 7	$ 6	$ 21
Pre-tax gains (losses) recognized during the period in income		(14)	0	(18)	(6)
Interest Rate Derivatives
Interest Rate Derivatives [Abstract]
Derivative Liability, Notional Amount		0		0
Commodity Trading Contract \| Other Derivative Instruments
Interest Rate Derivatives [Abstract]
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		0		0	0
Pre-tax gains (losses) recognized during the period in income	[1]	(14)		(13)	(1)
Electric Commodity \| Other Derivative Instruments
Interest Rate Derivatives [Abstract]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		0	0	0	0
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)	[2]	(2)	(7)	6	21
Pre-tax gains (losses) recognized during the period in income		$ 0	$ 0	0	0
Natural Gas Commodity \| Other Derivative Instruments
Interest Rate Derivatives [Abstract]
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)				0	0
Pre-tax gains (losses) recognized during the period in income	[3],[4]			$ (5)	$ (5)

[1] Recorded to electric revenues. Presented amounts do not reflect non-derivative transactions or margin sharing with customers. 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. Recorded to cost of natural gas sold and transported. These losses are subject to cost-recovery mechanisms and reclassified out of income to a regulatory asset, as appropriate.

Commodity Derivatives (Details)

Commodity Derivatives (Details) MWh in Millions, MMBTU in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2024 USD ($) MMBTU MWh	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) MMBTU MWh	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($) MMBTU MWh
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Miscellaneous investments		$ 55		$ 55		$ 51
Other Derivative Instruments
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Pre-tax fair value gains (losses) recognized during the period in accumulated other comprehensive loss		0	$ 0	0	$ 0
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		0	(11)	4	(26)
Designated as Hedging Instrument [Member] \| Cash Flow Hedges
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Pre-tax fair value gains (losses) recognized during the period in accumulated other comprehensive loss			8	16	4
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities			0	0	0
Cash flow hedge commodity
Derivative [Line Items]
Commodity contracts designated as cash flow hedges		$ 0		$ 0
Electric commodity
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Derivative, Nonmonetary Notional amount \| MWh	[1],[2]	58		58		38
Electric commodity \| Other Derivative Instruments
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		$ 0	(11)	$ 1	(28)
Natural Gas Commodity
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Derivative, Nonmonetary Notional amount \| MMBTU	[1],[2]	62		62		64
Electric Commodity \| Other Derivative Instruments
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		$ 0	0	$ 0	0
Natural gas commodity \| Other Derivative Instruments
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Pre-tax fair value gains (losses) recognized during the period in accumulated other comprehensive loss		0		0	0
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		$ 0		3	2
Interest Rate Contract [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedges
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Pre-tax fair value gains (losses) recognized during the period in accumulated other comprehensive loss			8	16	4
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities			$ 0	$ 0	$ 0

[1] Not reflective of net positions in the underlying commodities. Notional amounts for options included on a gross basis but weighted for the probability of exercise.

Consideration of Credit Risk an

Consideration of Credit Risk and Concentrations (Details) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2024 USD ($) Counterparty	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) Counterparty	Jun. 30, 2023 USD ($)
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract]
Fair Value Hedges, Net		$ 0	$ 0	$ 0	$ 0
Other Derivative Instruments
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract]
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		0	(11)	4	(26)
Pre-tax (gains) losses reclassified into income during the period from regulatory assets and (liabilities)		(2)	(7)	(6)	(21)
Pre-tax gains (losses) recognized during the period in income		(14)	0	(18)	(6)
Pre-tax fair value gains (losses) recognized during the period in accumulated other comprehensive loss		0	0	0	0
Commodity Trading Contract \| Other Derivative Instruments
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract]
Pre-tax (gains) losses reclassified into income during the period from regulatory assets and (liabilities)		0		0	0
Pre-tax gains (losses) recognized during the period in income	[1]	(14)		(13)	(1)
Electric Commodity \| Other Derivative Instruments
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract]
Pre-tax (gains) losses reclassified into income during the period from accumulated other comprehensive loss		0	0	0	0
Pre-tax (gains) losses reclassified into income during the period from regulatory assets and (liabilities)	[2]	2	7	(6)	(21)
Pre-tax gains (losses) recognized during the period in income		0	0	0	0
Natural Gas Commodity \| Other Derivative Instruments
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract]
Pre-tax (gains) losses reclassified into income during the period from regulatory assets and (liabilities)				0	0
Pre-tax gains (losses) recognized during the period in income	[3],[4]			(5)	(5)
Natural gas commodity \| Other Derivative Instruments
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract]
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		0		3	2
Pre-tax fair value gains (losses) recognized during the period in accumulated other comprehensive loss		0		0	0
Electric commodity \| Other Derivative Instruments
Impact of Derivative Activity on Accumulated Other Comprehensive Loss, Regulatory Assets and Liabilities, and Income [Abstract]
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		$ 0	$ (11)	$ 1	$ (28)
Credit Concentration Risk
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure \| Counterparty		10		10
Credit Concentration Risk \| Municipal or Cooperative Entities or Other Utilities [Member]
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure \| Counterparty		4		4
Credit Concentration Risk \| External Credit Rating, Investment Grade [Member]
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure \| Counterparty		3		3
Wholesale, trading and non trading commodity credit exposure for the most significant counterparties		$ 21		$ 21
Percentage of wholesale, trading and non trading commodity credit exposure for the most significant counterparties		19%		19%
Credit Concentration Risk \| Internal Investment Grade [Member]
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure \| Counterparty		3		3
Wholesale, trading and non trading commodity credit exposure for the most significant counterparties		$ 25		$ 25
Percentage of wholesale, trading and non trading commodity credit exposure for the most significant counterparties		23%		23%
Credit Concentration Risk \| External Credit Rating, Non Investment Grade [Member]
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure \| Counterparty		4		4
Wholesale, trading and non trading commodity credit exposure for the most significant counterparties		$ 61		$ 61
Percentage of wholesale, trading and non trading commodity credit exposure for the most significant counterparties		56%		56%

[1] Recorded to electric revenues. Presented amounts do not reflect non-derivative transactions or margin sharing with customers. 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. Recorded to cost of natural gas sold and transported. These losses are subject to cost-recovery mechanisms and reclassified out of income to a regulatory asset, as appropriate.

Credit Related Contingent Featu

Credit Related Contingent Features (Details) $ in Millions		3 Months Ended		6 Months Ended
Credit Related Contingent Features (Details) $ in Millions		Jun. 30, 2024 USD ($) Counterparty	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) Counterparty	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Fair Value Disclosures [Abstract]
Derivative instruments in a gross liability position		$ 17		$ 17		$ 12
Derivative, Gross Liability with Cross Default Position, Aggregate Fair Value		86		86		80
Collateral posted related to adequate assurance clauses in derivative contracts		0		0		0
Derivative [Line Items]
Fair Value Hedges, Net		0	$ 0	0	$ 0
Derivative instruments in a gross liability position		17		17		12
Derivative, Gross Liability with Cross Default Position, Aggregate Fair Value		86		86		80
Collateral Already Posted Adequate Assurance Clauses Aggregate Fair Value		$ 0		$ 0		$ 0
Credit Concentration Risk
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure \| Counterparty		10		10
Credit Concentration Risk \| Municipal or Cooperative Entities or Other Utilities [Member]
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure \| Counterparty		4		4
External Credit Rating, Investment Grade [Member] \| Credit Concentration Risk
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure \| Counterparty		3		3
Wholesale, trading and non trading commodity credit exposure for the most significant counterparties		$ 21		$ 21
Percentage of wholesale, trading and non trading commodity credit exposure for the most significant counterparties		19%		19%
Internal Investment Grade [Member] \| Credit Concentration Risk
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure \| Counterparty		3		3
Wholesale, trading and non trading commodity credit exposure for the most significant counterparties		$ 25		$ 25
Percentage of wholesale, trading and non trading commodity credit exposure for the most significant counterparties		23%		23%
External Credit Rating, Non Investment Grade [Member] \| Credit Concentration Risk
Derivative [Line Items]
Number of most significant counterparties for wholesale, trading and non-trading commodity activities with credit exposure \| Counterparty		4		4
Wholesale, trading and non trading commodity credit exposure for the most significant counterparties		$ 61		$ 61
Percentage of wholesale, trading and non trading commodity credit exposure for the most significant counterparties		56%		56%
Other Derivative Instruments
Derivative [Line Items]
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		$ 2	7	$ 6	21
Pre-tax gains (losses) recognized during the period in income		(14)	0	(18)	(6)
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		0	(11)	4	(26)
Commodity Trading Contract \| Other Derivative Instruments
Derivative [Line Items]
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		0		0	0
Pre-tax gains (losses) recognized during the period in income	[1]	(14)		(13)	(1)
Electric Commodity \| Other Derivative Instruments
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		0	0	0	0
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)	[2]	(2)	(7)	6	21
Pre-tax gains (losses) recognized during the period in income		0	0	0	0
Natural Gas Commodity \| Other Derivative Instruments
Derivative [Line Items]
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)				0	0
Pre-tax gains (losses) recognized during the period in income	[3],[4]			(5)	(5)
Natural gas commodity \| Other Derivative Instruments
Derivative [Line Items]
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		0		3	2
Electric commodity \| Other Derivative Instruments
Derivative [Line Items]
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		$ 0	$ (11)	$ 1	$ (28)

[1] Recorded to electric revenues. Presented amounts do not reflect non-derivative transactions or margin sharing with customers. 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. Recorded to cost of natural gas sold and transported. These losses are subject to cost-recovery mechanisms and reclassified out of income to a regulatory asset, as appropriate.

Recurring Fair Value Measuremen

Recurring Fair Value Measurements (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Derivatives, Fair Value [Line Items]
Derivative liability		$ 38		$ 38		$ 44
Derivative Liability, Noncurrent		91		91		86
Obligation to return cash		0		0		0
Right to reclaim cash		3		3		3
Changes in Level 3 Commodity Derivatives [Roll Forward]
Miscellaneous investments		55		55		51
Commodity Trading
Changes in Level 3 Commodity Derivatives [Roll Forward]
Balance at beginning of period		39	$ 46	51	$ 107
Settlements	[1]	(27)	(15)	(42)	(28)
Gains recognized in earnings (b)	[2]	3	12	3	(2)
Net gains (losses) recognized as regulatory assets and liabilities (a)	[1]	6	(23)	9	(57)
Balance at end of period		93	117	93	117
Purchases (a)	[1]	72	$ 97	72	$ 97
Fair Value Measured on a Recurring Basis
Derivatives, Fair Value [Line Items]
Derivative asset, gross		130		130		99
Netting, asset	[3]	(47)		(47)		(49)
Derivative Asset, Noncurrent		73		73		61
Derivative liability, gross		80		80		88
Netting, liability	[3]	(48)		(48)		(50)
Derivative liability		32		32		38
Derivative Liability, Noncurrent		72		72		64
Changes in Level 3 Commodity Derivatives [Roll Forward]
Derivative Asset, Current		83		83		50
Fair Value Measured on a Recurring Basis \| Level 1
Derivatives, Fair Value [Line Items]
Derivative asset, gross		5		5		7
Derivative liability, gross		6		6		6
Fair Value Measured on a Recurring Basis \| Level 2
Derivatives, Fair Value [Line Items]
Derivative asset, gross		38		38		37
Derivative liability, gross		65		65		70
Fair Value Measured on a Recurring Basis \| Level 3
Derivatives, Fair Value [Line Items]
Derivative asset, gross		87		87		55
Derivative liability, gross		9		9		12
Fair Value Measured on a Recurring Basis \| Other Derivative Instruments \| Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		62		62		71
Netting, asset	[3]	(44)		(44)		(42)
Derivative Asset, Noncurrent		73		73		61
Derivative liability, gross		77		77		71
Netting, liability	[3]	(45)		(45)		(43)
Derivative liability		32		32		28
Derivative Liability, Noncurrent		72		72		64
Changes in Level 3 Commodity Derivatives [Roll Forward]
Derivative Asset, Current		18		18		29
Fair Value Measured on a Recurring Basis \| Other Derivative Instruments \| Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		65		65		23
Netting, asset	[3]	(3)		(3)		(7)
Derivative liability, gross		3		3		7
Netting, liability	[3]	(3)		(3)		(7)
Derivative liability		0		0		0
Changes in Level 3 Commodity Derivatives [Roll Forward]
Derivative Asset, Current		62		62		16
Fair Value Measured on a Recurring Basis \| Other Derivative Instruments \| Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		3		3		5
Netting, asset	[3]	0		0		0
Derivative liability, gross		0		0		3
Netting, liability	[3]	0		0		0
Derivative liability		0		0		3
Changes in Level 3 Commodity Derivatives [Roll Forward]
Derivative Asset, Current		3		3		5
Fair Value Measured on a Recurring Basis \| Other Derivative Instruments \| Level 1 \| Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		5		5		7
Derivative liability, gross		6		6		6
Fair Value Measured on a Recurring Basis \| Other Derivative Instruments \| Level 1 \| Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		0		0		0
Derivative liability, gross		0		0		0
Fair Value Measured on a Recurring Basis \| Other Derivative Instruments \| Level 1 \| Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		0		0		0
Derivative liability, gross		0		0		0
Fair Value Measured on a Recurring Basis \| Other Derivative Instruments \| Level 2 \| Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		35		35		32
Derivative liability, gross		65		65		60
Fair Value Measured on a Recurring Basis \| Other Derivative Instruments \| Level 2 \| Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		0		0		0
Derivative liability, gross		0		0		0
Fair Value Measured on a Recurring Basis \| Other Derivative Instruments \| Level 2 \| Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		3		3		5
Derivative liability, gross		0		0		3
Fair Value Measured on a Recurring Basis \| Other Derivative Instruments \| Level 3 \| Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		22		22		32
Derivative liability, gross		6		6		5
Fair Value Measured on a Recurring Basis \| Other Derivative Instruments \| Level 3 \| Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		65		65		23
Derivative liability, gross		3		3		7
Fair Value Measured on a Recurring Basis \| Other Derivative Instruments \| Level 3 \| Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		0		0		0
Derivative liability, gross		$ 0		$ 0		$ 0
Fair Value Measured on a Recurring Basis \| Designated as Hedging Instrument [Member] \| Interest Rate Derivatives \| Cash Flow Hedges
Changes in Level 3 Commodity Derivatives [Roll Forward]
Derivative Liability, Current, Statement of Financial Position [Extensible Enumeration]		Other Liabilities, Current		Other Liabilities, Current		Other Liabilities, Current
Fair Value Measured on a Recurring Basis \| Other Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross		$ 108		$ 108		$ 95
Netting, asset	[3]	(35)		(35)		(34)
Fair Value Measured on a Recurring Basis \| Other Noncurrent Assets \| Level 1
Derivatives, Fair Value [Line Items]
Derivative asset, gross		5		5		7
Fair Value Measured on a Recurring Basis \| Other Noncurrent Assets \| Level 2
Derivatives, Fair Value [Line Items]
Derivative asset, gross		46		46		43
Fair Value Measured on a Recurring Basis \| Other Noncurrent Assets \| Level 3
Derivatives, Fair Value [Line Items]
Derivative asset, gross		57		57		45
Fair Value Measured on a Recurring Basis \| Other Noncurrent Assets \| Other Derivative Instruments \| Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		108		108		95
Netting, asset	[3]	(35)		(35)		(34)
Fair Value Measured on a Recurring Basis \| Other Noncurrent Assets \| Other Derivative Instruments \| Level 1 \| Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		5		5		7
Fair Value Measured on a Recurring Basis \| Other Noncurrent Assets \| Other Derivative Instruments \| Level 2 \| Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		46		46		43
Fair Value Measured on a Recurring Basis \| Other Noncurrent Assets \| Other Derivative Instruments \| Level 3 \| Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		57		57		45
Fair Value Measured on a Recurring Basis \| Other Current Liabilities \| Designated as Hedging Instrument [Member] \| Interest Rate Derivatives
Derivatives, Fair Value [Line Items]
Netting, liability		0		0		0
Fair Value Measured on a Recurring Basis \| Other Current Liabilities \| Designated as Hedging Instrument [Member] \| Interest Rate Derivatives \| Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Derivative liability, gross		0		0		7
Fair Value Measured on a Recurring Basis \| Other Current Liabilities \| Designated as Hedging Instrument [Member] \| Level 1 \| Interest Rate Derivatives \| Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Derivative liability, gross		0		0		0
Fair Value Measured on a Recurring Basis \| Other Current Liabilities \| Designated as Hedging Instrument [Member] \| Level 2 \| Interest Rate Derivatives \| Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Derivative liability, gross		0		0		7
Fair Value Measured on a Recurring Basis \| Other Current Liabilities \| Designated as Hedging Instrument [Member] \| Level 3 \| Interest Rate Derivatives \| Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Derivative liability, gross		0		0		0
Fair Value Measured on a Recurring Basis \| Other Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross		109		109		100
Netting, liability	[3]	(37)		(37)		(36)
Fair Value Measured on a Recurring Basis \| Other Noncurrent Liabilities \| Level 1
Derivatives, Fair Value [Line Items]
Derivative liability, gross		11		11		14
Fair Value Measured on a Recurring Basis \| Other Noncurrent Liabilities \| Level 2
Derivatives, Fair Value [Line Items]
Derivative liability, gross		56		56		49
Fair Value Measured on a Recurring Basis \| Other Noncurrent Liabilities \| Level 3
Derivatives, Fair Value [Line Items]
Derivative liability, gross		42		42		37
Fair Value Measured on a Recurring Basis \| Other Noncurrent Liabilities \| Other Derivative Instruments \| Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative liability, gross		109		109		100
Netting, liability	[3]	(37)		(37)		(36)
Fair Value Measured on a Recurring Basis \| Other Noncurrent Liabilities \| Other Derivative Instruments \| Level 1 \| Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative liability, gross		11		11		14
Fair Value Measured on a Recurring Basis \| Other Noncurrent Liabilities \| Other Derivative Instruments \| Level 2 \| Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative liability, gross		56		56		49
Fair Value Measured on a Recurring Basis \| Other Noncurrent Liabilities \| Other Derivative Instruments \| Level 3 \| Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative liability, gross		42		42		37
Fair Value, Measurements, Nonrecurring \| PPAs
Derivatives, Fair Value [Line Items]
Derivative liability	[4]	6		6		6
Derivative Liability, Noncurrent	[4]	$ 19		$ 19		$ 22

[1] Relates primarily to FTR instruments administered by MISO. Relates to commodity trading and is subject to substantial offsetting losses and gains on derivative instruments categorized as levels 1 and 2 in the consolidated income statement. See above tables for the income statement impact of derivative activity, including commodity trading gains and losses. NSP-Minnesota nets derivative instruments and related collateral on its consolidated balance sheets when supported by a legally enforceable master netting agreement. At June 30, 2024 and Dec. 31, 2023, derivative assets and liabilities include no obligations to return cash collateral. At both June 30, 2024 and Dec. 31, 2023 derivative assets and liabilities include rights to reclaim cash collateral of $3 million. Counterparty netting amounts presented exclude settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements. NSP-Minnesota 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 Long-Term Debt (D

Fair Value of Long-Term Debt (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying amount	$ 8,020	$ 7,330
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 6,847	$ 6,561

Benefit Plans and Other Postr_3

Benefit Plans and Other Postretirement Benefits (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended		6 Months Ended
		Jan. 31, 2024	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pension Plan [Member]
Components of Net Periodic Benefit Cost [Abstract]
Service Cost			$ 6	$ 5	$ 11	$ 10
Interest cost (a)	[1]		8	9	17	18
Expected return on plan assets (a)	[1]		(12)	(11)	(23)	(23)
Amortization of net loss (a)	[1]		3	3	6	6
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	[2]		31	0	31	0
Net periodic benefit cost			36	6	42	11
Effects of regulation			(32)	3	(29)	5
Net benefit cost recognized for financial reporting			4	9	13	16
Total contributions to the pension plans during the period		$ 41
Pension Plan [Member] \| Xcel Energy Inc.
Components of Net Periodic Benefit Cost [Abstract]
Total contributions to the pension plans during the period		$ 100
Other Postretirement Benefits Plan [Member]
Components of Net Periodic Benefit Cost [Abstract]
Service Cost			0	0	0	0
Interest cost (a)	[1]		0	1	1	1
Expected return on plan assets (a)	[1]		0	0	0	0
Amortization of net loss (a)	[1]		0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	[2]		0	0	0	0
Net periodic benefit cost			0	1	1	1
Effects of regulation			0	0	0	0
Net benefit cost recognized for financial reporting			$ 0	$ 1	$ 1	$ 1

[1] The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the consolidated statements of income or capitalized on the consolidated balance sheets as a regulatory asset. A settlement charge is required when the amount of lump-sum distributions during the year is greater than the sum of the service and interest cost components of the annual net periodic pension cost.

Commitments and Contingencies -

Commitments and Contingencies - Sherco (Details) - USD ($) $ in Millions	1 Months Ended
	Jan. 31, 2021	May 17, 2024	Sep. 22, 2023	Jun. 16, 2023
Rate Matters [Abstract]
Customer refund of previously recovered purchased power costs	$ 17
Amount MPUC previously disallowed related to Sherco outage	$ 22
Public Utilities, General Disclosures [Line Items]
Sherco Largge Industrial Customer group recommended refund				$ 72
ALJ Recommended Customer Refund		$ 34
Disallowance Not Considered in ALJ Recommendation		$ 22
NSP Minnesota [Member]
Public Utilities, General Disclosures [Line Items]
DOC Recommendation Based on Xcel's GE Litigation Loss of Use			$ 56

Commitments and Contingencies_2

Commitments and Contingencies - Environmental, MGP, Landfill or Disposal Sites (Details) $ in Millions	Jun. 30, 2024 USD ($)
Site Contingency [Line Items]
Cost of identified MGP, landfill, or disposal sites under current investigation and/or remediation	$ 1
Other MGP, Landfill, or Disposal Sites
Site Contingency [Line Items]
Number of identified MGP, landfill, or disposal sites under current investigation and/or remediation	7

Commitments and Contingencies_3

Commitments and Contingencies - Environmental Requirements - Water and Waste (Details) $ in Millions	Jun. 30, 2024 USD ($)
Site Contingency [Line Items]
Liability for estimated cost to comply with regulation	$ 45
Cost of Coal Ash Removal Projects	60
Legacy CCR Investigation and Remediation Costs	$ 6

Commitments and Contingencies_4

Commitments and Contingencies - Leases (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2024		Jun. 30, 2023		Jun. 30, 2024		Jun. 30, 2023		Dec. 31, 2023
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	$ 28	[1]	$ 29	[1]	$ 56	[2]	$ 58	[2]
Lessee, Operating Lease, Liability, to be Paid	614				614
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(157)				(157)
Operating Lease, Liability	457				457
Operating Lease, Liability, Current	(94)				(94)				$ (91)
Operating lease liabilities	363				363				$ 372
Purchased Power Agreements
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	25		24		48		49
Lessee, Operating Lease, Liability, to be Paid	352				352
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(29)				(29)
Operating Lease, Liability	323				323
Property, Plant and Equipment, Other Types
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	3	[3]	$ 5	[3]	8	[4]	$ 9	[4]
Lessee, Operating Lease, Liability, to be Paid	262				262
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(128)				(128)
Operating Lease, Liability	$ 134				$ 134

[1] PPA capacity payments are included in electric fuel and purchased power on the consolidated statements of income. Expense for other operating leases is included in O&M expense and electric fuel and purchased power. Includes immaterial short-term lease expense for both 2024 and 2023 . Includes immaterial short-term lease expense for both 2024 and 2023 .

Commitments and Contingencies_5

Commitments and Contingencies - Variable Interest Entities (Details) - MW	Jun. 30, 2024	Dec. 31, 2023
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Variable Interest Entity [Line Items]
Generating capacity under long term purchased power agreements	1,347	1,347

Commitments and Contingencies_6

Commitments and Contingencies - Minnesota FCA (Details) - USD ($) $ in Millions	May 15, 2024	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Proposed Refund - 2023 FCA		$ 126
DOC Recommended Refund - 2023 FCA	$ 20
OAG Recommended Refund - 2023 FCA	$ 18

Other Comprehensive Income (L_3

Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income at beginning of period			$ 8,207
Accumulated other comprehensive (loss) income at end of period	$ 8,855		8,855
Income Tax Expense (Benefit)	(51)	$ (50)	(74)	$ (92)
Gains and Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income at beginning of period	(6)	(19)	(18)	(16)
Accumulated other comprehensive (loss) income at end of period	(6)	(13)	(6)	(13)
Other Comprehensive Income (Loss), Net of Tax	0	6	12	3
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	6	12
Gains and Losses on Cash Flow Hedges \| Interest Rate Swap [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				3
Defined Benefit Pension and Postretirement Items
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income at beginning of period	(2)	(2)	(2)	(2)
Accumulated other comprehensive (loss) income at end of period	(2)	(2)	(2)	(2)
Other Comprehensive Income (Loss), Net of Tax	0	0	0	0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0	0
Defined Benefit Pension and Postretirement Items \| Interest Rate Swap [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				0
Total
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income at beginning of period	(8)	(21)	(20)	(18)
Accumulated other comprehensive (loss) income at end of period	(8)	(15)	(8)	(15)
Other Comprehensive Income (Loss), Net of Tax	0	6	12	3
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	$ 0	$ 6	$ 12
Total \| Interest Rate Swap [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				$ 3

Segment Information (Details)

Segment Information (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
Segment Information (Details) - USD ($) $ in Millions	Jun. 30, 2024		Jun. 30, 2023		Jun. 30, 2024		Jun. 30, 2023
Segment Reporting Information [Line Items]
Net income	$ 131		$ 127		$ 342		$ 266
Natural gas	90		98		363		498
Other	3		12		11		22
Regulated and Unregulated Operating Revenue	1,330		1,299		2,866	[1],[2]	2,965	[1],[2]
Affiliate Revenue	120		113		242		238
Total revenues
Segment Reporting Information [Line Items]
Regulated and Unregulated Operating Revenue	1,330	[3],[4]	1,299	[3],[4]	2,867		2,966
Intersegment Eliminations
Segment Reporting Information [Line Items]
Regulated and Unregulated Operating Revenue					(1)		(1)
Regulated Electric
Segment Reporting Information [Line Items]
Net income	122		134		267		245
Revenues Including Intersegment Revenues	1,237	[3]	1,189	[3]	2,492	[2]	2,445	[2]
Regulated Natural Gas
Segment Reporting Information [Line Items]
Net income	4		(9)		55		21
Revenues Including Intersegment Revenues					364		499
Regulated Natural Gas \| Total revenues
Segment Reporting Information [Line Items]
Natural gas	90	[4]	98	[4]	363	[1]	498	[1]
Regulated Natural Gas \| Intersegment Eliminations
Segment Reporting Information [Line Items]
Natural gas					1		1
All Other
Segment Reporting Information [Line Items]
Net income	5		2		20		0
All Other \| Total revenues
Segment Reporting Information [Line Items]
Other	$ 3		$ 12		$ 11		$ 22

[1] Operating revenues include an immaterial amount of affiliate gas revenue for the six months ended June 30, 2024 and 2023. Total revenues include $242 million and $238 million of affiliate electric revenue for the six months ended June 30, 2024 and 2023. Total revenues include $120 million and $113 million of affiliate electric revenue for the three months ended June 30, 2024 and 2023. Total revenues include an immaterial amount of affiliate gas revenue for the three months ended June 30, 2024 and 2023.