Northern States Power 10-Q 27 Oct 22 2022 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2022	Oct. 27, 2022
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	2022
Document Fiscal Period Focus	Q3
Amendment Flag	false
Document Period End Date	Sep. 30, 2022
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		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating revenues
Electric, non-affiliates	$ 1,598	$ 1,350	$ 3,914	$ 3,469
Electric, affiliates	132	127	394	373
Natural gas	102	70	703	353
Other	12	10	33	29
Total operating revenues	1,844	1,557	5,044	4,224
Operating expenses
Electric fuel and purchased power	750	574	1,857	1,494
Cost of natural gas sold and transported	65	30	510	187
Cost of sales — other	7	6	19	16
O&M expenses	305	287	915	899
Conservation program expenses	45	35	135	101
Depreciation and amortization	256	239	759	689
Taxes (other than income taxes)	69	65	210	200
Total operating expenses	1,497	1,236	4,405	3,586
Operating income	347	321	639	638
Other (expense) income, net	(4)	0	(9)	4
Allowance for funds used during construction — equity	9	8	21	23
Interest charges and financing costs
Interest charges — includes other financing costs of $2, $2, $6 and $6, respectively	75	69	216	202
Allowance for funds used during construction — debt	(4)	(3)	(9)	(9)
Total interest charges and financing costs	71	66	207	193
Income before income taxes	281	263	444	472
Income tax expense (benefit)	12	15	(70)	(17)
Net income	$ 269	$ 248	$ 514	$ 489

CONSOLIDATED STATEMENTS OF IN_2

CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Other financing costs	$ 2	$ 2	$ 6	$ 6

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Comprehensive income:
Net income	$ 269	$ 248	$ 514	$ 489
Derivative instruments:
Reclassification of losses to net income, net of tax of $—, $—, $— and $—, respectively	0	0	0	(1)
Total other comprehensive income	0	0	0	1
Total comprehensive income	$ 269	$ 248	$ 514	$ 490

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement of Comprehensive Income [Abstract]
Reclassification of losses on derivatives to net income, tax	$ 0	$ 0	$ 0	$ 0

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating activities
Net income	$ 514	$ 489
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	765	694
Nuclear fuel amortization	91	86
Deferred income taxes	(167)	(2)
Allowance for equity funds used during construction	(21)	(23)
Provision for bad debts	10	17
Gain (loss) on hedging and derivative transactions	23	(27)
Changes in operating assets and liabilities:
Accounts receivable	(56)	(55)
Accrued unbilled revenues	40	21
Inventories	(107)	(1)
Other current assets	5	1
Accounts payable	57	81
Net regulatory assets and liabilities	325	(312)
Other current liabilities	88	15
Pension and other employee benefit obligations	(9)	(38)
Other, net	9	(24)
Net cash provided by operating activities	1,567	922
Investing activities
Capital/construction expenditures	(1,293)	(1,368)
Purchase of investment securities	(1,055)	(540)
Proceeds from the sale of investment securities	1,029	531
Investments in utility money pool arrangement	(1,426)	(464)
Repayments from utility money pool arrangement	1,408	394
Other, net	5	3
Net cash used in investing activities	(1,332)	(1,444)
Financing activities
Repayments of short-term borrowings, net	0	(179)
Borrowings under utility money pool arrangement	0	434
Repayments under utility money pool arrangement	0	(434)
Proceeds from issuance of long-term debt	489	836
Repayment of long-term debt	(300)	0
Capital contributions from parent	4	644
Dividends paid to parent	(442)	(322)
Net cash (used in) provided by financing activities	(249)	979
Net change in cash, cash equivalents and restricted cash	(14)	457
Cash, cash equivalents and restricted cash at beginning of period	73	46
Cash, cash equivalents and restricted cash at end of period	59	503
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(198)	(189)
Cash (paid) received for income taxes, net	(53)	9
Other Noncash Investing and Financing Items [Abstract]
Accrued property, plant and equipment additions	162	233
Inventory transfers to property, plant and equipment	9	8
Allowance for equity funds used during construction	$ 21	$ 23

CONSOLIDATED BALANCE SHEETS (UN

CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Current assets
Cash, cash equivalents and restricted cash at beginning of period	$ 59	$ 73
Accounts receivable, net	495	429
Accounts receivable from affiliates	16	29
Investments in money pool arrangements	109	91
Accrued unbilled revenues	279	319
Inventories	407	309
Regulatory assets	436	527
Derivative instruments	168	53
Prepayments and other	42	46
Total current assets	2,011	1,876
Property, plant and equipment, net	17,070	16,430
Other assets
Nuclear decommissioning fund and other investments	2,789	3,308
Regulatory assets	953	718
Derivative instruments	74	33
Operating lease right-of-use assets	346	408
Other	29	36
Total other assets	4,191	4,503
Total assets	23,272	22,809
Current liabilities
Current portion of long-term debt	400	300
Accounts payable	586	522
Accounts payable to affiliates	89	63
Regulatory liabilities	250	117
Taxes accrued	311	260
Accrued interest	80	78
Dividends payable to parent	117	96
Derivative instruments	58	35
Operating lease liabilities	97	90
Other	233	166
Total current liabilities	2,221	1,727
Deferred credits and other liabilities
Deferred income taxes	1,667	1,949
Deferred investment tax credits	16	17
Regulatory liabilities	1,976	1,927
Asset retirement obligations	2,699	2,585
Derivative instruments	103	71
Pension and employee benefit obligations	105	112
Operating lease liabilities	280	353
Other	29	48
Total deferred credits and other liabilities	6,875	7,062
Capitalization
Long-term debt	6,541	6,447
Common stock — 5,000,000 shares authorized of $0.01 par value; 1,000,000 shares outstanding at Sept. 30, 2022 and Dec. 31, 2021, 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	$ 5,213	$ 5,202
Retained earnings	2,442	2,391
Accumulated other comprehensive loss	(20)	(20)
Total common stockholder's equity	7,635	7,573
Total liabilities and equity	$ 23,272	$ 22,809

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, 2020		1,000,000
Beginning balance at Dec. 31, 2020	$ 6,769	$ 0	$ 4,585	$ 2,206	$ (22)
Increase (Decrease) in Stockholders' Equity
Net income	489			489
Other comprehensive income	1				1
Dividends declared on common stock	(325)			(325)
Contribution of capital by parent	624		624
Balance (in shares) at Sep. 30, 2021		1,000,000
Ending balance at Sep. 30, 2021	7,558	$ 0	5,209	2,370	(21)
Balance (in shares) at Jun. 30, 2021		1,000,000
Beginning balance at Jun. 30, 2021	7,395	$ 0	5,185	2,231	(21)
Increase (Decrease) in Stockholders' Equity
Net income	248			248
Other comprehensive income	0
Dividends declared on common stock	(109)			(109)
Contribution of capital by parent	24		24
Balance (in shares) at Sep. 30, 2021		1,000,000
Ending balance at Sep. 30, 2021	$ 7,558	$ 0	5,209	2,370	(21)
Balance (in shares) at Dec. 31, 2021	1,000,000	1,000,000
Beginning balance at Dec. 31, 2021	$ 7,573	$ 0	5,202	2,391	(20)
Increase (Decrease) in Stockholders' Equity
Net income	514			514
Other comprehensive income	0
Dividends declared on common stock	(463)			(463)
Contribution of capital by parent	$ 11		11
Balance (in shares) at Sep. 30, 2022	1,000,000	1,000,000
Ending balance at Sep. 30, 2022	$ 7,635	$ 0	5,213	2,442	(20)
Balance (in shares) at Jun. 30, 2022		1,000,000
Beginning balance at Jun. 30, 2022	7,548	$ 0	5,213	2,355	(20)
Increase (Decrease) in Stockholders' Equity
Net income	269			269
Other comprehensive income	0
Dividends declared on common stock	$ (182)			(182)
Balance (in shares) at Sep. 30, 2022	1,000,000	1,000,000
Ending balance at Sep. 30, 2022	$ 7,635	$ 0	$ 5,213	$ 2,442	$ (20)

Management's Opinion

Management's Opinion	9 Months Ended
	Sep. 30, 2022
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 Sept. 30, 2022 and Dec. 31, 2021; the results of NSP-Minnesota’s operations, including the components of net income and comprehensive income, and changes in stockholder’s equity for the three and nine months ended Sept. 30, 2022 and 2021; and NSP-Minnesota’s cash flows for the nine months ended Sept. 30, 2022 and 2021. All adjustments are of a normal, recurring nature, except as otherwise disclosed. Management has also evaluated the impact of events occurring after Sept. 30, 2022 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, 2021 balance sheet information has been derived from the audited 2021 consolidated financial statements included in the NSP-Minnesota Annual Report on Form 10-K for the year ended Dec. 31, 2021. 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, 2021, filed with the SEC on Feb. 23, 2022. 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	9 Months Ended
	Sep. 30, 2022
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, 2021 appropriately represent, in all material respects, the current status of accounting policies and are incorporated herein by reference.

Accounting Pronouncements

Accounting Pronouncements	9 Months Ended
	Sep. 30, 2022
Accounting Standards Update and Change in Accounting Principle [Abstract]
Accounting Pronouncements	As of Sept. 30, 2022, there was no material impact from the recent adoption of new accounting pronouncements, nor expected material impact from recently issued accounting pronouncements yet to be adopted, on NSP-Minnesota’s consolidated financial statements.

Selected Balance Sheet Data

Selected Balance Sheet Data	9 Months Ended
	Sep. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Selected Balance Sheet Data	(Millions of Dollars) Sept. 30, 2022 Dec. 31, 2021 Accounts receivable, net Accounts receivable $ 538 $ 474 Less allowance for bad debts (43) (45) Accounts receivable, net $ 495 $ 429 (Millions of Dollars) Sept. 30, 2022 Dec. 31, 2021 Inventories Materials and supplies $ 197 $ 181 Fuel 117 81 Natural gas 93 47 Total inventories $ 407 $ 309 (Millions of Dollars) Sept. 30, 2022 Dec. 31, 2021 Property, plant and equipment, net Electric plant $ 20,044 $ 19,154 Natural gas plant 1,993 1,864 Common and other property 1,091 1,007 Plant to be retired (a) 682 719 Construction work in progress 1,102 984 Total property, plant and equipment 24,912 23,728 Less accumulated depreciation (8,083) (7,606) Nuclear fuel 3,105 3,081 Less accumulated amortization (2,864) (2,773) Property, plant and equipment, net $ 17,070 $ 16,430 (a) Amounts include regulator-approved retirements of Sherco Units 1, 2 and 3 and A.S. King and are reported net of accumulated depreciation.

Borrowings and Other Financing

Borrowings and Other Financing Instruments	9 Months Ended
	Sep. 30, 2022
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 for NSP-Minnesota: (Amounts in Millions, Except Interest Rates) Three Months Ended Sept. 30, 2022 Year Ended Dec. 31, 2021 Borrowing limit $ 250 $ 250 Amount outstanding at period end — — Average amount outstanding — 6 Maximum amount outstanding — 236 Weighted average interest rate, computed on a daily basis N/A 0.07 % Weighted average interest rate at period end N/A N/A Commercial Paper — Commercial paper outstanding for NSP-Minnesota: (Amounts in Millions, Except Interest Rates) Three Months Ended Sept. 30, 2022 Year Ended Dec. 31, 2021 Borrowing limit $ 700 $ 500 Amount outstanding at period end — — Average amount outstanding — 26 Maximum amount outstanding — 317 Weighted average interest rate, computed on a daily basis N/A 0.18 % Weighted average interest rate at period end N/A N/A Letters of Credit — NSP-Minnesota uses letters of credit, generally with terms of one year, to provide financial guarantees for certain obligations. There w ere $11 million and $9 million of letters of credit outstanding under the credit facility at Sept. 30, 2022 and Dec. 31, 2021, 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 in place at least equal to the amount of its 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. In September 2022, NSP-Minnesota entered into an amended five-year credit agreement with a syndicate of banks, with substantially the same terms and conditions as the prior credit agreements. The borrowing limit for NSP-Minnesota was increased from $500 million to $700 million, and the maturity was extended from June 2024 to September 2027. 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 Sept. 30, 2022, NSP-Minnesota had the following committed revolving credit facility available (in millions of dollars): Credit Facility (a) Drawn (b) Available $ 700 $ 11 $ 689 (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 h ad no d irect advances on the credit facility outstanding at Sept. 30, 2022 and Dec. 31, 2021. Bilateral Credit Agreement — In April 2022, 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 Sept. 30, 2022, NSP-Minnesota had $50 million of outstanding letters of credit under the $75 million bilateral credit agreement. Long-Term Borrowings During the nine months ended September 30, 2022, NSP-Minnesota issued $500 million of 4.50% first mortgage bonds due June 1, 2052.

Revenues

Revenues	9 Months Ended
	Sep. 30, 2022
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 Sept. 30, 2022 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 441 $ 37 $ 10 $ 488 C&I 714 43 — 757 Other 10 — 2 12 Total retail 1,165 80 12 1,257 Wholesale 242 — — 242 Transmission 101 — — 101 Interchange 132 — — 132 Other 8 10 — 18 Total revenue from contracts with customers 1,648 90 12 1,750 Alternative revenue and other 82 12 — 94 Total revenues $ 1,730 $ 102 $ 12 $ 1,844 Three Months Ended Sept. 30, 2021 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 414 $ 27 $ 9 $ 450 C&I 638 26 — 664 Other 9 — 1 10 Total retail 1,061 53 10 1,124 Wholesale 120 — — 120 Transmission 69 — — 69 Interchange 127 — — 127 Other — 6 — 6 Total revenue from contracts with customers 1,377 59 10 1,446 Alternative revenue and other 100 11 — 111 Total revenues $ 1,477 $ 70 $ 10 $ 1,557

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Income Taxes	6. Income Taxes Reconciliation between the statutory rate and ETR: Nine Months Ended Sept. 30 2022 2021 Federal statutory rate 21.0 % 21.0 % State tax (net of federal tax effect) 7.0 7.0 Increases (decreases): Wind PTCs (a) (35.9) (22.8) Plant regulatory differences (b) (7.0) (8.0) Other tax credits, net operating loss & tax credit allowances (1.3) (1.2) Other (net) 0.4 0.4 Effective income tax rate (15.8) % (3.6) % (a) Wind PTCs are credited to customers (reduction to revenue) and do not materially impact net income. (b) Regulatory differences for income tax primarily relate to the credit of excess deferred taxes to customers through the average rate assumption method. Income tax benefits associated with the credit of excess deferred taxes are offset by corresponding revenue reductions.

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities	Fair Value Measurements Accounting guidance for fair value measurements and disclosures provides a single definition of fair value and requires disclosures about assets and liabilities measured at fair value. A hierarchical framework for disclosing the observability of the inputs utilized in measuring assets and liabilities at fair value is established by this guidance. • 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 highly liquid and actively traded instruments with quoted prices. • Level 2 — Pricing inputs are other than quoted 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 are those valued with models requiring significant management judgment or estimation. Specific valuation methods include: Cash equivalents — The fair values of cash equivalents are generally based on cost plus accrued interest; money market funds are measured using quoted NAV. 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 fund investments 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’ investments 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 — The 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 contractual settlements relate to inactive delivery locations or extend to periods beyond those readily observable on active exchanges or quoted by brokers, 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 a 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. 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 regulatory asset. Unrealized gains for the nuclear decommissioning fund were $900 million and $1.3 billion as of Sept. 30, 2022 and Dec. 31, 2021, respectively, and unrealized losses were $133 million and $7 million as of Sept. 30, 2022 and Dec. 31, 2021, respectively. Non-derivative instruments with recurring fair value measurements in the nuclear decommissioning fund: Sept. 30, 2022 Fair Value (Millions of Dollars) Cost Level 1 Level 2 Level 3 NAV Total Nuclear decommissioning fund (a) Cash equivalents $ 37 $ 37 $ — $ — $ — $ 37 Commingled funds 832 — — — 1,167 1,167 Debt securities 696 — 611 9 — 620 Equity securities 409 918 1 — — 919 Total $ 1,974 $ 955 $ 612 $ 9 $ 1,167 $ 2,743 (a) Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $46 million of other investments, including the rabbi trust. Dec. 31, 2021 Fair Value (Millions of Dollars) Cost Level 1 Level 2 Level 3 NAV Total Nuclear decommissioning fund (a) Cash equivalents $ 64 $ 64 $ — $ — $ — $ 64 Commingled funds 856 — — — 1,294 1,294 Debt securities 631 — 666 9 — 675 Equity securities 411 1,222 1 — — 1,223 Total $ 1,962 $ 1,286 $ 667 $ 9 $ 1,294 $ 3,256 (a) Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $52 million of other investments, including the rabbi trust. For the three and nine months ended Sept. 30, 2022 and 2021, there were immaterial Level 3 nuclear decommissioning fund investments or transfer of amounts between levels. Contractual maturity dates of debt securities in the nuclear decommissioning fund as of Sept. 30, 2022: 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 $ 190 $ 227 $ 198 $ 620 Derivative Instruments 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, utility commodity prices and vehicle fuel prices. Interest Rate Derivatives — NSP-Minnesota enters into various instruments that effectively fix the yield or price on a specified benchmark interest rate for an anticipated debt issuance for a specific period. These derivative instruments are generally designated as cash flow hedges for accounting purposes, with changes in fair value prior to settlement recorded as other comprehensive income. At Sept. 30, 2022, accumulated other comprehensive loss related to interest rate derivatives included $1 million of net losses expected to be reclassified into earnings during the next 12 months as the hedged interest rate transactions impact earnings. As of Sept. 30, 2022, NSP-Minnesota had no unsettled interest rate derivatives. Wholesale and Commodity Trading Risk — 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. Sharing of any 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, as well as for trading purposes. This could include the purchase or sale of energy or energy-related products, natural gas to generate electric energy, natural gas for resale, FTRs, vehicle fuel, and weather derivatives. NSP-Minnesota may enter into derivative instruments that mitigate commodity price risk on behalf of electric and natural gas customers, but may not be designated as qualifying hedging transactions. The classification of gains or losses for these instruments as a regulatory asset or liability, if applicable, is based on approved regulatory recovery mechanisms. As of Sept. 30, 2022, NSP-Minnesota had no commodity contracts designated as cash flow hedges. NSP-Minnesota also enters into commodity derivative instruments for trading purposes not directly related to commodity price risks associated with serving its electric and natural gas customers. Changes in the fair value of these commodity derivatives are recorded in electric operating revenues, net of amounts credited to customers under margin-sharing mechanisms. Gross notional amounts of commodity forwards, options and FTRs: (Amounts in Millions) (a)(b) Sept. 30, 2022 Dec. 31, 2021 Megawatt hours of electricity 59 57 Million British thermal units of natural gas 99 85 (a) Amounts are not reflective of net positions in the underlying commodities. (b) Notional amounts for options are included on a gross basis, but are 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 Sept. 30, 2022, eight of NSP-Minnesota’s ten most significant counterparties for these activities, comprising $45 million, or 35%, of this credit exposure, had investment grade credit ratings from S&P Global Ratings, Moody’s Investor Services or Fitch Ratings. One of the ten most significant counterparties, comprising $29 million, or 22%, 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. One of these significant counterparties, comprising $55 million or 42% 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. Impact of Derivative Activity — Pre-Tax Fair Value Gains (Losses) Recognized During the Period in: (Millions of Dollars) Regulatory (Assets) and Liabilities Three Months Ended Sept. 30, 2022 Other derivative instruments Electric commodity $ 20 Natural gas commodity $ (2) Total $ 18 Nine Months Ended Sept. 30, 2022 Other derivative instruments Electric commodity $ 26 Total $ 26 Three Months Ended Sept. 30, 2021 Other derivative instruments Natural gas commodity $ 16 Total $ 16 Nine Months Ended Sept. 30, 2021 Other derivative instruments Electric commodity $ 3 Natural gas commodity 18 Total $ 21 Pre-Tax (Gains) Losses Reclassified into Income During the Period from: Pre-Tax Gains (Losses) Recognized During the Period in Income (Millions of Dollars) Accumulated Other Comprehensive Loss Regulatory Assets and (Liabilities) Three Months Ended Sept. 30, 2022 Other derivative instruments Commodity trading $ — $ — $ 11 (b) Electric commodity — (2) (c) — Total $ — $ (2) $ 11 Nine Months Ended Sept. 30, 2022 Other derivative instruments Commodity trading $ — $ — $ 17 (b) Electric commodity — (5) (c) — Natural gas commodity — 2 (d) (5) (d)(e) Total $ — $ (3) $ 12 Pre-Tax (Gains) Losses Reclassified Pre-Tax Gains (Losses) (Millions of Dollars) Accumulated Other Comprehensive Loss Regulatory Three Months Ended Sept. 30, 2021 Other derivative instruments Commodity trading $ — $ — $ (10) (b) Total $ — $ — $ (10) Nine Months Ended Sept. 30, 2021 Derivatives designated as cash flow hedges Interest rate $ 1 (a) $ — $ — Total $ 1 $ — $ — Other derivative instruments Commodity trading $ — $ — $ 23 (b) Electric commodity — (12) (c) — Natural gas commodity — 1 (d) (3) (d)(e) Total $ — $ (11) $ 20 (a) Recorded to interest charges. (b) Recorded to electric operating revenues. Portions of these gains and losses are subject to sharing with electric customers through margin-sharing mechanisms and deducted from gross revenue, as appropriate. (c) 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. All 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. (d) 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. (e) Relates primarily to option premium amortization. NSP-Minnesota had no derivative instruments designated as fair value hedges during the three and nine months ended Sept. 30, 2022 and 2021. Credit Related Contingent Features — Contract provisions for derivative instruments that NSP-Minnesota enters into, including those accounted for as normal purchase-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 NSP-Minnesota’s credit ratings are downgraded below its investment grade credit rating by any of the major credit rating agencies. As of Sept. 30, 2022 and Dec. 31, 2021, there were $5 million and $3 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 the other financing arrangements related to payment terms or other covenants. As of Sept. 30, 2022 and Dec. 31, 2021, there were approximately $88 million and $48 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 NSP-Minnesota’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 Sept. 30, 2022 and Dec. 31, 2021. Recurring Fair Value Measurements — NSP-Minnesota’s derivative assets and liabilities measured at fair value on a recurring basis were as follows: Sept. 30, 2022 Dec. 31, 2021 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 $ 25 $ 68 $ 47 $ 140 $ (98) $ 42 $ 9 $ 40 $ 22 $ 71 $ (53) $ 18 Electric commodity (b) — — 124 124 (4) 120 — — 30 30 (1) 29 Natural gas commodity — 6 — 6 — 6 — 6 — 6 — 6 Total current derivative assets $ 25 $ 74 $ 171 $ 270 $ (102) $ 168 $ 9 $ 46 $ 52 $ 107 $ (54) $ 53 Noncurrent derivative assets Other derivative instruments: Commodity trading $ 30 $ 42 $ 76 $ 148 $ (74) $ 74 $ 6 $ 34 $ 35 $ 75 $ (42) $ 33 Total noncurrent derivative assets $ 30 $ 42 $ 76 $ 148 $ (74) $ 74 $ 6 $ 34 $ 35 $ 75 $ (42) $ 33 Sept. 30, 2022 Dec. 31, 2021 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 Other derivative instruments: Commodity trading $ 33 $ 99 $ 9 $ 141 $ (100) $ 41 $ 13 $ 58 $ 4 $ 75 $ (58) $ 17 Electric commodity (b) — — 4 4 (4) — — — 1 1 (1) — Natural gas commodity — 3 — 3 — 3 — 4 — 4 — 4 Total current derivative liabilities $ 33 $ 102 $ 13 $ 148 $ (104) 44 $ 13 $ 62 $ 5 $ 80 $ (59) 21 PPAs (c) 14 14 Current derivative instruments $ 58 $ 35 Noncurrent derivative liabilities Other derivative instruments: Commodity trading $ 50 $ 61 $ 42 $ 153 $ (80) $ 73 $ 15 $ 48 $ 26 $ 89 $ (53) $ 36 Total noncurrent derivative liabilities $ 50 $ 61 $ 42 $ 153 $ (80) 73 $ 15 $ 48 $ 26 $ 89 $ (53) 36 PPAs (c) 30 35 Noncurrent derivative instruments $ 103 $ 71 (a) NSP-Minnesota nets derivative instruments and related collateral on its consolidated balance sheets when supported by a legally enforceable master netting agreement. At Sept. 30, 2022 and Dec. 31, 2021, derivatives include $2 million and no obligations to return cash collateral, respectively. At Sept. 30, 2022 and Dec. 31, 2021 derivative assets and liabilities include rights to reclaim cash collateral of $9 million and $16 million, respectively. Counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements. (b) Amounts relate to FTR instruments administered by MISO (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, fair values for FTRs are offset/deferred as a regulatory asset or liability and do not have a material impact on net income. (c) During 2006, Xcel Energy qualified these contracts under the normal purchase exception. Based on this qualification, the contracts are no longer adjusted to fair value and the previous carrying value of these contracts will be amortized over the remaining contract lives along with the offsetting regulatory assets and liabilities. Changes in Level 3 commodity derivatives for the three and nine months ended Sept. 30, 2022 and 2021: Three Months Ended Sept. 30 (Millions of Dollars) 2022 2021 Balance at July 1 $ 230 $ 92 Purchases/Issuances (a) — — Settlements (a) (88) (40) Net transactions recorded during the period: Gains recognized in earnings (b) 15 23 Net gains recognized as regulatory assets and liabilities (a) 35 15 Balance at Sept. 30 $ 192 $ 90 Nine Months Ended Sept. 30 (Millions of Dollars) 2022 2021 Balance at Jan. 1 $ 56 $ (11) Purchases/Issuances (a) 157 54 Settlements (a) (180) (66) Net transactions recorded during the period: Gains recognized in earnings (b) 106 86 Net gains recognized as regulatory assets and liabilities (a) 53 27 Balance at Sept. 30 $ 192 $ 90 (a) Relates primarily to FTR instruments administered by MISO (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, changes in fair value are deferred as a regulatory asset or liability and do not have a material impact on net income. (b) Relates to commodity trading and is subject to offsetting losses of derivative instruments categorized as levels 1 and 2 in the consolidated income statement. Fair Value of Long-Term Debt Other financial instruments for which the carrying amount did not equal fair value: Sept. 30, 2022 Dec. 31, 2021 (Millions of Dollars) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt, including current portion $ 6,941 $ 5,881 $ 6,747 $ 7,761 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 Sept. 30, 2022 and Dec. 31, 2021 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	9 Months Ended
	Sep. 30, 2022
Retirement Benefits [Abstract]
Benefit Plans and Other Postretirement Benefits	Components of Net Periodic Benefit Cost Three Months Ended Sept. 30 2022 2021 2022 2021 (Millions of Dollars) Pension Benefits Postretirement Health Service cost $ 6 $ 7 $ — $ — Interest cost (a) 7 7 — — Expected return on plan assets (a) (12) (13) — — Amortization of prior service credit (a) — — (1) — Amortization of net loss (a) 6 9 1 — Settlement charge (b) 29 23 — — Net periodic benefit cost 36 33 — — Effects of regulation (32) (28) — — Net benefit cost recognized for financial reporting $ 4 $ 5 $ — $ — Nine Months Ended Sept. 30 2022 2021 2022 2021 (Millions of Dollars) Pension Benefits Postretirement Health Service cost $ 20 $ 22 $ — $ — Interest cost (a) 19 19 1 1 Expected return on plan assets (a) (36) (39) — — Amortization of prior service credit (a) — — (2) (2) Amortization of net loss (a) 18 26 1 1 Settlement charge (b) 28 23 — — Net periodic benefit cost 49 51 — — Effects of regulation (31) (30) — — Net benefit cost recognized for financial reporting $ 18 $ 21 $ — $ — (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 all 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 third quarter of 2022 and 2021 as a result of lump-sum distributions during the 2022 and 2021 plan years, NSP-Minnesota recorded pension settlement charges of $29 million and $23 million, respectively, which were not recognized in earnings due to the effects of rate making. In January 2022, contributions of $50 million were made across four of Xcel Energy’s pension plans, of which $5 million was attributable to NSP-Minnesota. Xcel Energy does not expect additional pension contributions during 2022.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2022
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 for repair. 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 March 2020, NSP-Minnesota’s insurers filed a petition seeking additional review by the Minnesota Supreme Court. In April 2020, the Minnesota Supreme Court denied the insurers’ petition for further review, ending the litigation. In January 2021, the OAG and DOC recommended that NSP-Minnesota refund approximately $17 million of replacement power costs previously recovered through the fuel clause adjustment. NSP-Minnesota subsequently filed its response, asserting 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. A final decision by the MPUC is expected in mid-2023. A loss related to this matter is deemed remote. MISO ROE Complaints — In November 2013 and February 2015, customer groups filed two ROE complaints against MISO TOs, which includes NSP-Minnesota and NSP-Wisconsin. The first complaint requested a reduction in base ROE transmission formula rates from 12.38% to 9.15% for the time period of Nov. 12, 2013 to Feb. 11, 2015, and removal of ROE adders (including those for RTO membership). The second complaint requested, for a subsequent time period, a base ROE reduction from 12.38% to 8.67%. Environmental 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 its best estimate of costs/liabilities from final resolution of these issues, however, the outcome and timing are unknown. In addition, there may be insurance recovery and/or recovery from other potentially responsible parties, offsetting a portion of costs incurred. Environmental Requirements — Water and Waste Coal Ash Regulation — NSP-Minnesota’s operations are subject to federal and state regulations that impose requirements for handling, storage, treatment and disposal of solid waste. Under the CCR Rule, utilities are required to complete groundwater sampling around their CCR landfills and surface impoundments. Currently, NSP-Minnesota has three regulated ash units in operation. NSP-Minnesota is conducting groundwater sampling and monitoring and implementing assessment of corrective measures at certain CCR landfills and surface impoundments. No results above the groundwater protection standards in the rule were identified. Federal 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 $36 million may be required to comply with the requirements. NSP-Minnesota anticipates these costs will be recoverable through regulatory mechanisms. Leases NSP-Minnesota evaluates contracts that may contain leases, including PPAs and arrangements for the use of office space and other facilities, vehicles and equipment. A contract contains a lease if it conveys the exclusive right to control the use of a specific asset. Components of lease expense: Three Months Ended Sept. 30 (Millions of Dollars) 2022 2021 Operating leases PPA capacity payments $ 25 $ 17 Other operating leases (a) 2 1 Total operating lease expense (b) $ 27 $ 18 (a) Includes $1 million and $0 million of short-term lease expense for 2022 and 2021, respectively. (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. Nine Months Ended Sept. 30 (Millions of Dollars) 2022 2021 Operating leases PPA capacity payments $ 74 $ 53 Other operating leases (a) 6 6 Total operating lease expense (b) $ 80 $ 59 (a) Includes short-term lease expen se of $2 million fo r 2022 and $1 million for 2021. (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 Sept. 30, 2022: (Millions of Dollars) PPA Operating Other Operating Leases Total Leases Total minimum obligation $ 342 $ 67 $ 409 Interest component of obligation (22) (10) (32) Present value of minimum obligation $ 320 $ 57 377 Less current portion (97) Noncurrent operating lease liabilities $ 280 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 they purchase . These specific PPAs create a variable interest in the IPP. NSP-Minnesota had approximately 1,322 MW and 1,347 MW of capacity under long-term PPAs at Sept. 30, 2022 and Dec. 31, 2021, respectively, with entities that have been determined to be variable interest entities. NSP-Minnesota concluded that these entities are not required to be consolidated in its financial statements because it does not have the power to direct the activities that most significantly impact the ent ities’ economic performance. The PPAs have expiration dates through 2039.

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2022
Stockholders' Equity Note [Abstract]
Other Comprehensive Income (Loss)	Changes in accumulated other comprehensive income (loss), net of tax, for the three and nine months ended Sept. 30, 2022 and 2021: Three Months Ended Sept. 30, 2022 Three Months Ended Sept. 30, 2021 (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 July 1 $ (17) $ (3) $ (20) $ (18) $ (3) $ (21) Losses reclassified from net accumulated other comprehensive loss: Interest rate derivatives (a) — — — — — — Accumulated other comprehensive loss at Sept. 30 $ (17) $ (3) $ (20) $ (18) $ (3) $ (21) Nine Months Ended Sept. 30, 2022 Nine Months Ended Sept. 30, 2021 (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 $ (17) $ (3) $ (20) $ (19) $ (3) $ (22) Losses reclassified from net accumulated other comprehensive loss: Interest rate derivatives (a) — — — 1 — 1 Accumulated other comprehensive loss at Sept. 30 $ (17) $ (3) $ (20) $ (18) $ (3) $ (21) (a) Included in interest charges.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2022
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, 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 Sept. 30 (Millions of Dollars) 2022 2021 Regulated Electric Total revenues (a) $ 1,730 $ 1,477 Net income 275 245 Regulated Natural Gas Operating revenues (b) $ 102 $ 70 Intersegment revenue — 1 Total revenues $ 102 $ 71 Net loss (12) (2) All Other Total revenues $ 12 $ 10 Net income 6 5 Consolidated Total Operating revenues (a)(b) $ 1,844 $ 1,558 Reconciling eliminations — (1) Total revenues $ 1,844 $ 1,557 Net income 269 248 (a) Operating revenues include $132 million and $127 million of affiliate electric revenue for the three months ended Sept. 30, 2022 and 2021. (b) Operating revenues include an immaterial amount of affiliate gas revenue for the three months ended Sept. 30, 2022 and 2021. Nine Months Ended Sept. 30 (Millions of Dollars) 2022 2021 Regulated Electric Total revenues (a) $ 4,308 $ 3,842 Net income 486 464 Regulated Natural Gas Operating revenues (b) $ 703 $ 353 Intersegment revenue 1 1 Total revenues $ 704 $ 354 Net income 21 18 All Other Total operating revenues $ 33 $ 29 Net income 7 7 Consolidated Total Operating revenues (a)(b) $ 5,045 $ 4,225 Reconciling eliminations (1) (1) Total operating revenues $ 5,044 $ 4,224 Net income 514 489 (a) Operating revenues include $394 million and $373 million of affiliate electric revenue for the nine months ended Sept. 30, 2022 and 2021. (b) Operating revenues include an immaterial amount of affiliate gas revenue for the nine months ended Sept. 30, 2022 and 2021.

Selected Balance Sheet Data (Ta

Selected Balance Sheet Data (Tables)	9 Months Ended
	Sep. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Accounts Receivable, Net	(Millions of Dollars) Sept. 30, 2022 Dec. 31, 2021 Accounts receivable, net Accounts receivable $ 538 $ 474 Less allowance for bad debts (43) (45) Accounts receivable, net $ 495 $ 429
Inventories	(Millions of Dollars) Sept. 30, 2022 Dec. 31, 2021 Inventories Materials and supplies $ 197 $ 181 Fuel 117 81 Natural gas 93 47 Total inventories $ 407 $ 309
Property, plant and equipment, net	(Millions of Dollars) Sept. 30, 2022 Dec. 31, 2021 Property, plant and equipment, net Electric plant $ 20,044 $ 19,154 Natural gas plant 1,993 1,864 Common and other property 1,091 1,007 Plant to be retired (a) 682 719 Construction work in progress 1,102 984 Total property, plant and equipment 24,912 23,728 Less accumulated depreciation (8,083) (7,606) Nuclear fuel 3,105 3,081 Less accumulated amortization (2,864) (2,773) Property, plant and equipment, net $ 17,070 $ 16,430 (a) Amounts include regulator-approved retirements of Sherco Units 1, 2 and 3 and A.S. King and are reported net of accumulated depreciation.

Borrowings and Other Financin_2

Borrowings and Other Financing Instruments (Tables)	9 Months Ended
	Sep. 30, 2022
Borrowings and Other Financing Instruments [Abstract]
Credit Facilities	At Sept. 30, 2022, NSP-Minnesota had the following committed revolving credit facility available (in millions of dollars): Credit Facility (a) Drawn (b) Available $ 700 $ 11 $ 689 (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 for NSP-Minnesota: (Amounts in Millions, Except Interest Rates) Three Months Ended Sept. 30, 2022 Year Ended Dec. 31, 2021 Borrowing limit $ 250 $ 250 Amount outstanding at period end — — Average amount outstanding — 6 Maximum amount outstanding — 236 Weighted average interest rate, computed on a daily basis N/A 0.07 % 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 for NSP-Minnesota: (Amounts in Millions, Except Interest Rates) Three Months Ended Sept. 30, 2022 Year Ended Dec. 31, 2021 Borrowing limit $ 700 $ 500 Amount outstanding at period end — — Average amount outstanding — 26 Maximum amount outstanding — 317 Weighted average interest rate, computed on a daily basis N/A 0.18 % Weighted average interest rate at period end N/A N/A

Revenues (Tables)

Revenues (Tables)	9 Months Ended
	Sep. 30, 2022
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	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 Sept. 30, 2022 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 441 $ 37 $ 10 $ 488 C&I 714 43 — 757 Other 10 — 2 12 Total retail 1,165 80 12 1,257 Wholesale 242 — — 242 Transmission 101 — — 101 Interchange 132 — — 132 Other 8 10 — 18 Total revenue from contracts with customers 1,648 90 12 1,750 Alternative revenue and other 82 12 — 94 Total revenues $ 1,730 $ 102 $ 12 $ 1,844 Three Months Ended Sept. 30, 2021 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 414 $ 27 $ 9 $ 450 C&I 638 26 — 664 Other 9 — 1 10 Total retail 1,061 53 10 1,124 Wholesale 120 — — 120 Transmission 69 — — 69 Interchange 127 — — 127 Other — 6 — 6 Total revenue from contracts with customers 1,377 59 10 1,446 Alternative revenue and other 100 11 — 111 Total revenues $ 1,477 $ 70 $ 10 $ 1,557 Nine Months Ended Sept. 30, 2022 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 1,116 $ 348 $ 19 $ 1,483 C&I 1,816 299 — 2,115 Other 29 — 14 43 Total retail 2,961 647 33 3,641 Wholesale 505 — — 505 Transmission 225 — — 225 Interchange 394 — — 394 Other 9 15 — 24 Total revenue from contracts with customers 4,094 662 33 4,789 Alternative revenue and other 214 41 — 255 Total revenues $ 4,308 $ 703 $ 33 $ 5,044 Nine Months Ended Sept. 30, 2021 (Millions of Dollars) Electric Natural Gas All Other Total Major revenue types Revenue from contracts with customers: Residential $ 1,074 $ 179 $ 24 $ 1,277 C&I 1,601 134 — 1,735 Other 25 — 5 30 Total retail 2,700 313 29 3,042 Wholesale 287 — — 287 Transmission 184 — — 184 Interchange 373 — — 373 Other 5 9 — 14 Total revenue from contracts with customers 3,549 322 29 3,900 Alternative revenue and other 293 31 — 324 Total revenues $ 3,842 $ 353 $ 29 $ 4,224

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	Reconciliation between the statutory rate and ETR: Nine Months Ended Sept. 30 2022 2021 Federal statutory rate 21.0 % 21.0 % State tax (net of federal tax effect) 7.0 7.0 Increases (decreases): Wind PTCs (a) (35.9) (22.8) Plant regulatory differences (b) (7.0) (8.0) Other tax credits, net operating loss & tax credit allowances (1.3) (1.2) Other (net) 0.4 0.4 Effective income tax rate (15.8) % (3.6) % (a) Wind PTCs are credited to customers (reduction to revenue) and do not materially impact net income. (b) Regulatory differences for income tax primarily relate to the credit of excess deferred taxes to customers through the average rate assumption method. Income tax benefits associated with the credit of excess deferred taxes are offset by corresponding revenue reductions.

Fair Value of Financial Asset_2

Fair Value of Financial Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Cost and Fair Value of Nuclear Decommissioning Fund Investments	Non-derivative instruments with recurring fair value measurements in the nuclear decommissioning fund: Sept. 30, 2022 Fair Value (Millions of Dollars) Cost Level 1 Level 2 Level 3 NAV Total Nuclear decommissioning fund (a) Cash equivalents $ 37 $ 37 $ — $ — $ — $ 37 Commingled funds 832 — — — 1,167 1,167 Debt securities 696 — 611 9 — 620 Equity securities 409 918 1 — — 919 Total $ 1,974 $ 955 $ 612 $ 9 $ 1,167 $ 2,743 (a) Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $46 million of other investments, including the rabbi trust. Dec. 31, 2021 Fair Value (Millions of Dollars) Cost Level 1 Level 2 Level 3 NAV Total Nuclear decommissioning fund (a) Cash equivalents $ 64 $ 64 $ — $ — $ — $ 64 Commingled funds 856 — — — 1,294 1,294 Debt securities 631 — 666 9 — 675 Equity securities 411 1,222 1 — — 1,223 Total $ 1,962 $ 1,286 $ 667 $ 9 $ 1,294 $ 3,256 (a) Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $52 million of other investments, including the rabbi trust.
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 Sept. 30, 2022: 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 $ 190 $ 227 $ 198 $ 620
Gross Notional Amounts of Commodity Forwards, Options, and FTRs	Gross notional amounts of commodity forwards, options and FTRs: (Amounts in Millions) (a)(b) Sept. 30, 2022 Dec. 31, 2021 Megawatt hours of electricity 59 57 Million British thermal units of natural gas 99 85 (a) Amounts are not reflective of net positions in the underlying commodities. (b) Notional amounts for options are included on a gross basis, but are 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) Regulatory (Assets) and Liabilities Three Months Ended Sept. 30, 2022 Other derivative instruments Electric commodity $ 20 Natural gas commodity $ (2) Total $ 18 Nine Months Ended Sept. 30, 2022 Other derivative instruments Electric commodity $ 26 Total $ 26 Three Months Ended Sept. 30, 2021 Other derivative instruments Natural gas commodity $ 16 Total $ 16 Nine Months Ended Sept. 30, 2021 Other derivative instruments Electric commodity $ 3 Natural gas commodity 18 Total $ 21 Pre-Tax (Gains) Losses Reclassified into Income During the Period from: Pre-Tax Gains (Losses) Recognized During the Period in Income (Millions of Dollars) Accumulated Other Comprehensive Loss Regulatory Assets and (Liabilities) Three Months Ended Sept. 30, 2022 Other derivative instruments Commodity trading $ — $ — $ 11 (b) Electric commodity — (2) (c) — Total $ — $ (2) $ 11 Nine Months Ended Sept. 30, 2022 Other derivative instruments Commodity trading $ — $ — $ 17 (b) Electric commodity — (5) (c) — Natural gas commodity — 2 (d) (5) (d)(e) Total $ — $ (3) $ 12 Pre-Tax (Gains) Losses Reclassified Pre-Tax Gains (Losses) (Millions of Dollars) Accumulated Other Comprehensive Loss Regulatory Three Months Ended Sept. 30, 2021 Other derivative instruments Commodity trading $ — $ — $ (10) (b) Total $ — $ — $ (10) Nine Months Ended Sept. 30, 2021 Derivatives designated as cash flow hedges Interest rate $ 1 (a) $ — $ — Total $ 1 $ — $ — Other derivative instruments Commodity trading $ — $ — $ 23 (b) Electric commodity — (12) (c) — Natural gas commodity — 1 (d) (3) (d)(e) Total $ — $ (11) $ 20 (a) Recorded to interest charges. (b) Recorded to electric operating revenues. Portions of these gains and losses are subject to sharing with electric customers through margin-sharing mechanisms and deducted from gross revenue, as appropriate. (c) 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. All 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. (d) 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. (e) Relates primarily to option premium amortization.
Derivative Assets and Liabilities Measured at Fair Value on a Recurring Basis by Hierarchy Level	Recurring Fair Value Measurements — NSP-Minnesota’s derivative assets and liabilities measured at fair value on a recurring basis were as follows: Sept. 30, 2022 Dec. 31, 2021 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 $ 25 $ 68 $ 47 $ 140 $ (98) $ 42 $ 9 $ 40 $ 22 $ 71 $ (53) $ 18 Electric commodity (b) — — 124 124 (4) 120 — — 30 30 (1) 29 Natural gas commodity — 6 — 6 — 6 — 6 — 6 — 6 Total current derivative assets $ 25 $ 74 $ 171 $ 270 $ (102) $ 168 $ 9 $ 46 $ 52 $ 107 $ (54) $ 53 Noncurrent derivative assets Other derivative instruments: Commodity trading $ 30 $ 42 $ 76 $ 148 $ (74) $ 74 $ 6 $ 34 $ 35 $ 75 $ (42) $ 33 Total noncurrent derivative assets $ 30 $ 42 $ 76 $ 148 $ (74) $ 74 $ 6 $ 34 $ 35 $ 75 $ (42) $ 33 Sept. 30, 2022 Dec. 31, 2021 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 Other derivative instruments: Commodity trading $ 33 $ 99 $ 9 $ 141 $ (100) $ 41 $ 13 $ 58 $ 4 $ 75 $ (58) $ 17 Electric commodity (b) — — 4 4 (4) — — — 1 1 (1) — Natural gas commodity — 3 — 3 — 3 — 4 — 4 — 4 Total current derivative liabilities $ 33 $ 102 $ 13 $ 148 $ (104) 44 $ 13 $ 62 $ 5 $ 80 $ (59) 21 PPAs (c) 14 14 Current derivative instruments $ 58 $ 35 Noncurrent derivative liabilities Other derivative instruments: Commodity trading $ 50 $ 61 $ 42 $ 153 $ (80) $ 73 $ 15 $ 48 $ 26 $ 89 $ (53) $ 36 Total noncurrent derivative liabilities $ 50 $ 61 $ 42 $ 153 $ (80) 73 $ 15 $ 48 $ 26 $ 89 $ (53) 36 PPAs (c) 30 35 Noncurrent derivative instruments $ 103 $ 71 (a) NSP-Minnesota nets derivative instruments and related collateral on its consolidated balance sheets when supported by a legally enforceable master netting agreement. At Sept. 30, 2022 and Dec. 31, 2021, derivatives include $2 million and no obligations to return cash collateral, respectively. At Sept. 30, 2022 and Dec. 31, 2021 derivative assets and liabilities include rights to reclaim cash collateral of $9 million and $16 million, respectively. Counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements. (b) Amounts relate to FTR instruments administered by MISO (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, fair values for FTRs are offset/deferred as a regulatory asset or liability and do not have a material impact on net income. (c) During 2006, Xcel Energy qualified these contracts under the normal purchase exception. Based on this qualification, the contracts are no longer adjusted to fair value and the previous carrying value of these contracts will be 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 for the three and nine months ended Sept. 30, 2022 and 2021: Three Months Ended Sept. 30 (Millions of Dollars) 2022 2021 Balance at July 1 $ 230 $ 92 Purchases/Issuances (a) — — Settlements (a) (88) (40) Net transactions recorded during the period: Gains recognized in earnings (b) 15 23 Net gains recognized as regulatory assets and liabilities (a) 35 15 Balance at Sept. 30 $ 192 $ 90 Nine Months Ended Sept. 30 (Millions of Dollars) 2022 2021 Balance at Jan. 1 $ 56 $ (11) Purchases/Issuances (a) 157 54 Settlements (a) (180) (66) Net transactions recorded during the period: Gains recognized in earnings (b) 106 86 Net gains recognized as regulatory assets and liabilities (a) 53 27 Balance at Sept. 30 $ 192 $ 90 (a) Relates primarily to FTR instruments administered by MISO (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, changes in fair value are deferred as a regulatory asset or liability and do not have a material impact on net income. (b) Relates to commodity trading and is subject to offsetting losses of derivative instruments categorized as levels 1 and 2 in the consolidated income statement.
Carrying Amount and Fair Value of Long-term Debt	Other financial instruments for which the carrying amount did not equal fair value: Sept. 30, 2022 Dec. 31, 2021 (Millions of Dollars) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt, including current portion $ 6,941 $ 5,881 $ 6,747 $ 7,761

Benefit Plans and Other Postr_2

Benefit Plans and Other Postretirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2022
Retirement Benefits [Abstract]
Components of Net Periodic Benefit Cost (Credit)	Components of Net Periodic Benefit Cost Three Months Ended Sept. 30 2022 2021 2022 2021 (Millions of Dollars) Pension Benefits Postretirement Health Service cost $ 6 $ 7 $ — $ — Interest cost (a) 7 7 — — Expected return on plan assets (a) (12) (13) — — Amortization of prior service credit (a) — — (1) — Amortization of net loss (a) 6 9 1 — Settlement charge (b) 29 23 — — Net periodic benefit cost 36 33 — — Effects of regulation (32) (28) — — Net benefit cost recognized for financial reporting $ 4 $ 5 $ — $ — Nine Months Ended Sept. 30 2022 2021 2022 2021 (Millions of Dollars) Pension Benefits Postretirement Health Service cost $ 20 $ 22 $ — $ — Interest cost (a) 19 19 1 1 Expected return on plan assets (a) (36) (39) — — Amortization of prior service credit (a) — — (2) (2) Amortization of net loss (a) 18 26 1 1 Settlement charge (b) 28 23 — — Net periodic benefit cost 49 51 — — Effects of regulation (31) (30) — — Net benefit cost recognized for financial reporting $ 18 $ 21 $ — $ — (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.	[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	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Lease, Cost	Components of lease expense: Three Months Ended Sept. 30 (Millions of Dollars) 2022 2021 Operating leases PPA capacity payments $ 25 $ 17 Other operating leases (a) 2 1 Total operating lease expense (b) $ 27 $ 18 (a) Includes $1 million and $0 million of short-term lease expense for 2022 and 2021, respectively.	Nine Months Ended Sept. 30 (Millions of Dollars) 2022 2021 Operating leases PPA capacity payments $ 74 $ 53 Other operating leases (a) 6 6 Total operating lease expense (b) $ 80 $ 59 (a) Includes short-term lease expen se of $2 million fo r 2022 and $1 million for 2021.
Lessee, Operating Lease, Liability, Maturity		Commitments under operating leases as of Sept. 30, 2022: (Millions of Dollars) PPA Operating Other Operating Leases Total Leases Total minimum obligation $ 342 $ 67 $ 409 Interest component of obligation (22) (10) (32) Present value of minimum obligation $ 320 $ 57 377 Less current portion (97) Noncurrent operating lease liabilities $ 280

Other Comprehensive Income (L_2

Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2022
Stockholders' Equity Note [Abstract]
Changes in Accumulated Other Comprehensive Income (Loss), Net of Tax	Changes in accumulated other comprehensive income (loss), net of tax, for the three and nine months ended Sept. 30, 2022 and 2021: Three Months Ended Sept. 30, 2022 Three Months Ended Sept. 30, 2021 (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 July 1 $ (17) $ (3) $ (20) $ (18) $ (3) $ (21) Losses reclassified from net accumulated other comprehensive loss: Interest rate derivatives (a) — — — — — — Accumulated other comprehensive loss at Sept. 30 $ (17) $ (3) $ (20) $ (18) $ (3) $ (21) Nine Months Ended Sept. 30, 2022 Nine Months Ended Sept. 30, 2021 (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 $ (17) $ (3) $ (20) $ (19) $ (3) $ (22) Losses reclassified from net accumulated other comprehensive loss: Interest rate derivatives (a) — — — 1 — 1 Accumulated other comprehensive loss at Sept. 30 $ (17) $ (3) $ (20) $ (18) $ (3) $ (21) (a) Included in interest charges.

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2022
Segment Reporting [Abstract]
Results from Operations by Reportable Segment	NSP-Minnesota’s segment information: Three Months Ended Sept. 30 (Millions of Dollars) 2022 2021 Regulated Electric Total revenues (a) $ 1,730 $ 1,477 Net income 275 245 Regulated Natural Gas Operating revenues (b) $ 102 $ 70 Intersegment revenue — 1 Total revenues $ 102 $ 71 Net loss (12) (2) All Other Total revenues $ 12 $ 10 Net income 6 5 Consolidated Total Operating revenues (a)(b) $ 1,844 $ 1,558 Reconciling eliminations — (1) Total revenues $ 1,844 $ 1,557 Net income 269 248 (a) Operating revenues include $132 million and $127 million of affiliate electric revenue for the three months ended Sept. 30, 2022 and 2021. (b) Operating revenues include an immaterial amount of affiliate gas revenue for the three months ended Sept. 30, 2022 and 2021. Nine Months Ended Sept. 30 (Millions of Dollars) 2022 2021 Regulated Electric Total revenues (a) $ 4,308 $ 3,842 Net income 486 464 Regulated Natural Gas Operating revenues (b) $ 703 $ 353 Intersegment revenue 1 1 Total revenues $ 704 $ 354 Net income 21 18 All Other Total operating revenues $ 33 $ 29 Net income 7 7 Consolidated Total Operating revenues (a)(b) $ 5,045 $ 4,225 Reconciling eliminations (1) (1) Total operating revenues $ 5,044 $ 4,224 Net income 514 489 (a) Operating revenues include $394 million and $373 million of affiliate electric revenue for the nine months ended Sept. 30, 2022 and 2021. (b) Operating revenues include an immaterial amount of affiliate gas revenue for the nine months ended Sept. 30, 2022 and 2021.

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Accounts Receivable	$ 538	$ 474
Less allowance for bad debts	(43)	(45)
Accounts receivable, net	$ 495	$ 429

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Public Utilities, Inventory [Line Items]
Inventories	$ 407	$ 309
Materials and supplies
Public Utilities, Inventory [Line Items]
Inventories	197	181
Fuel
Public Utilities, Inventory [Line Items]
Inventories	117	81
Natural Gas
Public Utilities, Inventory [Line Items]
Inventories	$ 93	$ 47

Property, Plant and Equipment (

Property, Plant and Equipment (Details) - USD ($) $ in Millions		Sep. 30, 2022	Dec. 31, 2021
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		$ 24,912	$ 23,728
Accumulated depreciation and amortization		(8,083)	(7,606)
Property, plant and equipment, net		17,070	16,430
Electric plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		20,044	19,154
Natural gas plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		1,993	1,864
Common and other property
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		1,091	1,007
Plant to be Retired (a)
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	[1]	682	719
Construction work in progress
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		1,102	984
Nuclear fuel
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		3,105	3,081
Accumulated depreciation and amortization		$ (2,864)	$ (2,773)
[1]Amounts include regulator-approved retirements of Sherco Units 1, 2 and 3 and A.S. King and are reported net of accumulated depreciation.

Money Pool (Details)

Money Pool (Details) - Money Pool - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Short-term Debt [Line Items]
Borrowing limit	$ 250	$ 250
Amount outstanding at period end	0	0
Average amount outstanding	0	6
Maximum amount outstanding	$ 0	$ 236
Weighted average interest rate, computed on a daily basis		0.07%

Borrowings and Other Financin_3

Borrowings and Other Financing Instruments Commercial Paper (Details) - Commercial Paper - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Short-term Debt [Line Items]
Borrowing limit	$ 700	$ 500
Amount outstanding at period end	0	0
Average amount outstanding	0	26
Maximum amount outstanding	$ 0	$ 317
Weighted average interest rate, computed on a daily basis		0.18%

Letters of Credit (Details)

Letters of Credit (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Letter of Credit
Line of Credit Facility [Line Items]
Direct advances on the credit facility outstanding	$ 11	$ 9

Credit Facility (Details)

Credit Facility (Details) - Credit Facility $ in Millions		9 Months Ended
		Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Line of Credit Facility [Line Items]
Borrowing limit	[1]	$ 700
Amount outstanding at period end	[2]	$ 11
Number of extension you can request		2
Available		$ 689
Direct advances on the credit facility outstanding		$ 0	$ 0
[1]Expires in September 2027.[2]Includes outstanding commercial paper and letters of credit.

Bilateral Credit Agreement (Det

Bilateral Credit Agreement (Details)	9 Months Ended
	Sep. 30, 2022 USD ($)
Series Due June 1, 2052 | NSP Minnesota [Member] | Bonds [Member]
Short-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.50%
Debt Instrument, Face Amount	$ 500,000,000
Letter of Credit | Bilateral Credit Agreement
Short-term Debt [Line Items]
Borrowing Limit	75,000,000
Amount outstanding at period end	$ 50,000,000
Letter of Credit | Bilateral Credit Agreement | NSP Minnesota [Member]
Short-term Debt [Line Items]
Debt Instrument, Term	1 year

Revenues (Details)

Revenues (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,844	$ 1,557	$ 5,044	$ 4,224
Regulated Electric | Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	1,730	1,477	4,308	3,842
Regulated Natural Gas | Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	102	70	703	353
All Other | Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	12	10	33	29
Retail
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,257	1,124	3,641	3,042
Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	488	450	1,483	1,277
Retail | C&I
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	757	664	2,115	1,735
Retail | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	12	10	43	30
Retail | Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,165	1,061	2,961	2,700
Retail | Regulated Electric | Residential
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	441	414	1,116	1,074
Retail | Regulated Electric | C&I
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	714	638	1,816	1,601
Retail | Regulated Electric | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	10	9	29	25
Retail | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	80	53	647	313
Retail | Regulated Natural Gas | Residential
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	37	27	348	179
Retail | Regulated Natural Gas | C&I
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	43	26	299	134
Retail | Regulated Natural Gas | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Retail | All Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	12	10	33	29
Retail | All Other | Residential
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	10	9	19	24
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	2	1	14	5
Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	242	120	505	287
Wholesale | Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	242	120	505	287
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	101	69	225	184
Transmission | Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	101	69	225	184
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	132	127	394	373
Interchange | Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	132	127	394	373
Interchange | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Interchange | All Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0	0
Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	18	6	24	14
Other | Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	8	0	9	5
Other | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	10	6	15	9
Other | 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	1,750	1,446	4,789	3,900
Total revenue from contracts with customers | Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,648	1,377	4,094	3,549
Total revenue from contracts with customers | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	90	59	662	322
Total revenue from contracts with customers | All Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	12	10	33	29
Alternative revenue and other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	94	111	255	324
Alternative revenue and other | Regulated Electric
Disaggregation of Revenue [Line Items]
Alternative revenue and other	82	100	214	293
Alternative revenue and other | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Alternative revenue and other	12	11	41	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)		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Federal statutory rate		21%	21%
State tax (net of federal tax effect)		7%	7%
Wind PTCs	[1]	(35.90%)	(22.80%)
Plant regulatory differences	[2]	(7.00%)	(8.00%)
Other tax credits, net operating loss & tax credit allowances		(1.30%)	(1.20%)
Other (net)		0.40%	0.40%
Effective income tax rate		(15.80%)	(3.60%)
[1]Wind PTCs are credited to customers (reduction to revenue) and do not materially impact net income[2]Regulatory differences for income tax primarily relate to the credit of excess deferred taxes to customers through the average rate assumption method. Income tax benefits associated with the credit of excess deferred taxes are offset by corresponding revenue reductions.

Non-Derivative Fair Value Measu

Non-Derivative Fair Value Measurements (Details) - USD ($) $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2022		Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Miscellaneous investments	$ 46		$ 52
Debt Securities, Available-for-sale, Unrealized Gain	900		1,300
Debt Securities, Available-for-sale, Unrealized Loss	133		7
Final Contractual Maturity [Abstract]
Due in 1 Year or Less	5
Due in 1 to 5 Years	190
Due in 5 to 10 Years	227
Due after 10 Years	198
Total	620
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	696	[1]	631	[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	620	[1]	675	[2]
NAV	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 2 | Debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities	611	[1]	666	[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	9	[1]	9	[2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Cost
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	1,974	[1]	1,962	[2]
Nuclear Decommissioning Fund | 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	37	[1]	64	[2]
Nuclear Decommissioning Fund | 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	832	[1]	856	[2]
Nuclear Decommissioning Fund | 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	409	[1]	411	[2]
Nuclear Decommissioning Fund | Fair Value Measured on a Recurring Basis | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	2,743	[1]	3,256	[2]
NAV	1,167	[1]	1,294	[2]
Nuclear Decommissioning Fund | 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	37	[1]	64	[2]
NAV	0	[1]	0	[2]
Nuclear Decommissioning Fund | 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	1,167	[1]	1,294	[2]
NAV	1,167	[1]	1,294	[2]
Nuclear Decommissioning Fund | 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	919	[1]	1,223	[2]
NAV	0	[1]	0	[2]
Nuclear Decommissioning Fund | 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	955	[1]	1,286	[2]
Nuclear Decommissioning Fund | 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	37	[1]	64	[2]
Nuclear Decommissioning Fund | 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]
Nuclear Decommissioning Fund | 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	918	[1]	1,222	[2]
Nuclear Decommissioning Fund | 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	612	[1]	667	[2]
Nuclear Decommissioning Fund | 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]
Nuclear Decommissioning Fund | 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]
Nuclear Decommissioning Fund | 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]	1	[2]
Nuclear Decommissioning Fund | 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	9	[1]	9	[2]
Nuclear Decommissioning Fund | 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]
Nuclear Decommissioning Fund | 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]
Nuclear Decommissioning Fund | 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 $46 million of other investments, including the rabbi trust.[2]Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $52 million of other investments, including the rabbi trust.

Interest Rate Derivative (Detai

Interest Rate Derivative (Details) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2022		Sep. 30, 2021		Sep. 30, 2022		Sep. 30, 2021
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)		0		(3)		11
Pre-tax gains (losses) recognized during the period in income		11		(10)		12		20
Designated as Hedging Instrument [Member] | Cash Flow Hedges
Interest Rate Derivatives [Abstract]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net								1
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)								0
Pre-tax gains (losses) recognized during the period in income								0
Interest Rate Derivatives
Interest Rate Derivatives [Abstract]
Amount or interest rate derivatives expected to be reclassified		1				1
Derivative Liability, Notional Amount		0				0
Commodity Trading Contract | 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)		0		0		0		0
Pre-tax gains (losses) recognized during the period in income		11	[1]	$ (10)	[2]	17	[2]	23	[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
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		2	[2]			(5)	[3]	12	[2]
Pre-tax gains (losses) recognized during the period in income		$ 0				0		0
Natural Gas Commodity | Other Derivative Instruments
Interest Rate Derivatives [Abstract]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net						0		0
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)						(2)	[4]	(1)	[3]
Pre-tax gains (losses) recognized during the period in income	[3],[4]					$ (5)		(3)
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedges
Interest Rate Derivatives [Abstract]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	[5]							1
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)								0
Pre-tax gains (losses) recognized during the period in income								$ 0
[1]Recorded to electric operating revenues. Portions of these gains and losses are subject to sharing with electric customers through margin-sharing mechanisms and deducted from gross revenue, as appropriate.[2]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. All 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.[3]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.[4]Relates primarily to option premium amortization.[5]Recorded to interest charges.

Commodity Derivatives (Details)

Commodity Derivatives (Details) MWh in Millions, MMBTU in Millions, $ in Millions		Sep. 30, 2022 USD ($) MMBTU MWh	Dec. 31, 2021 USD ($) MWh MMBTU
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Miscellaneous investments		$ 46	$ 52
Cash flow hedge commodity
Derivative [Line Items]
Commodity contracts designated as cash flow hedges		$ 0
Electric commodity
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Derivative, Nonmonetary Notional amount | MWh	[1],[2]	59	57
Natural Gas Commodity
Gross Notional Amounts of Commodity Forwards, Options and FTRs [Abstract]
Derivative, Nonmonetary Notional amount | MMBTU	[1],[2]	99	85
[1]Amounts are not reflective of net positions in the underlying commodities.[2]Notional amounts for options are included on a gross basis, but are weighted for the probability of exercise.

Consideration of Credit Risk an

Consideration of Credit Risk and Concentrations (Details) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2022 USD ($) Counterparty		Sep. 30, 2021 USD ($)		Sep. 30, 2022 USD ($) Counterparty		Sep. 30, 2021 USD ($)
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		18		16		26		21
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		0		3		(11)
Pre-tax gains (losses) recognized during the period in income		11		(10)		12		20
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 accumulated other comprehensive loss		0		0		0		0
Pre-tax (gains) losses reclassified into income during the period from regulatory assets and (liabilities)		0		0		0		0
Pre-tax gains (losses) recognized during the period in income		11	[1]	(10)	[2]	17	[2]	23	[1]
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						26		3
Pre-tax (gains) losses reclassified into income during the period from accumulated other comprehensive loss		0				0		0
Pre-tax (gains) losses reclassified into income during the period from regulatory assets and (liabilities)		(2)	[2]			5	[3]	(12)	[2]
Pre-tax gains (losses) recognized during the period in income		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 accumulated other comprehensive loss						0		0
Pre-tax (gains) losses reclassified into income during the period from regulatory assets and (liabilities)						2	[4]	1	[3]
Pre-tax gains (losses) recognized during the period in income	[3],[4]					$ (5)		(3)
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		(2)		$ 16				$ 18
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		$ 20
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		8				8
Wholesale, trading and non trading commodity credit exposure for the most significant counterparties		$ 45				$ 45
Percentage of wholesale, trading and non trading commodity credit exposure for the most significant counterparties		35%				35%
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		1				1
Wholesale, trading and non trading commodity credit exposure for the most significant counterparties		$ 29				$ 29
Percentage of wholesale, trading and non trading commodity credit exposure for the most significant counterparties		22%				22%
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		1				1
Wholesale, trading and non trading commodity credit exposure for the most significant counterparties		$ 55				$ 55
Percentage of wholesale, trading and non trading commodity credit exposure for the most significant counterparties		42%				42%
[1]Recorded to electric operating revenues. Portions of these gains and losses are subject to sharing with electric customers through margin-sharing mechanisms and deducted from gross revenue, as appropriate.[2]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. All 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.[3]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.[4]Relates primarily to option premium amortization.

Credit Related Contingent Featu

Credit Related Contingent Features (Details) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2022 USD ($) Counterparty		Sep. 30, 2021 USD ($)		Sep. 30, 2022 USD ($) Counterparty		Sep. 30, 2021 USD ($)		Dec. 31, 2021 USD ($)
Fair Value Disclosures [Abstract]
Derivative instruments in a gross liability position		$ 5				$ 5				$ 3
Derivative, Gross Liability with Cross Default Position, Aggregate Fair Value		88				88				48
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		5				5				3
Derivative, Gross Liability with Cross Default Position, Aggregate Fair Value		$ 88				$ 88				$ 48
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		8				8
Wholesale, trading and non trading commodity credit exposure for the most significant counterparties		$ 45				$ 45
Percentage of wholesale, trading and non trading commodity credit exposure for the most significant counterparties		35%				35%
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		1				1
Wholesale, trading and non trading commodity credit exposure for the most significant counterparties		$ 29				$ 29
Percentage of wholesale, trading and non trading commodity credit exposure for the most significant counterparties		22%				22%
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		1				1
Wholesale, trading and non trading commodity credit exposure for the most significant counterparties		$ 55				$ 55
Percentage of wholesale, trading and non trading commodity credit exposure for the most significant counterparties		42%				42%
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)		0		(3)		11
Pre-tax gains (losses) recognized during the period in income		11		(10)		12		20
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		18		16		26		21
Commodity Trading Contract | 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)		0		0		0		0
Pre-tax gains (losses) recognized during the period in income		11	[1]	(10)	[2]	17	[2]	23	[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
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		2	[2]			(5)	[3]	12	[2]
Pre-tax gains (losses) recognized during the period in income		0				0		0
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities						26		3
Natural Gas Commodity | Other Derivative Instruments
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net						0		0
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)						(2)	[4]	(1)	[3]
Pre-tax gains (losses) recognized during the period in income	[3],[4]					$ (5)		(3)
Natural gas commodity | Other Derivative Instruments
Derivative [Line Items]
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		(2)		$ 16				$ 18
Electric commodity | Other Derivative Instruments
Derivative [Line Items]
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		$ 20
[1]Recorded to electric operating revenues. Portions of these gains and losses are subject to sharing with electric customers through margin-sharing mechanisms and deducted from gross revenue, as appropriate.[2]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. All 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.[3]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.[4]Relates primarily to option premium amortization.

Recurring Fair Value Measuremen

Recurring Fair Value Measurements (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Other Assets, Excluding Property, Plant and Equipment		Other Assets, Excluding Property, Plant and Equipment
Derivative liability		$ 58		$ 58		$ 35
Derivative Liability, Noncurrent		$ 103		$ 103		$ 71
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Other Liabilities, Noncurrent		Other Liabilities, Noncurrent
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Other Liabilities, Current		Other Liabilities, Current		Other Liabilities, Current
Obligation to return cash		$ 2		$ 2		$ 0
Right to reclaim cash		9		9		16
Commodity Trading
Changes in Level 3 Commodity Derivatives [Roll Forward]
Balance at beginning of period		230	$ 92	56	$ (11)
Settlements	[1]	(88)	(40)	(180)	(66)
Gains recognized in earnings (b)	[2]	15	23	106	86
Net gains recognized as regulatory assets and liabilities (a)	[1]	35	15	53	27
Balance at end of period		192	90	192	90
Purchases/Issuances (a)	[1]	0	0	157	$ 54
Fair Value Measured on a Recurring Basis
Derivatives, Fair Value [Line Items]
Derivative asset, gross		270		270		107
Netting, asset		(102)		(102)		(54)	[3]
Derivative Asset, Noncurrent		74		74		33
Derivative liability, gross		148		148		80
Netting, liability		(104)		(104)		(59)	[3]
Derivative liability		44		44		21
Derivative Liability, Noncurrent		73		73		36
Changes in Level 3 Commodity Derivatives [Roll Forward]
Derivative Asset, Current		168		168		53
Fair Value Measured on a Recurring Basis | Level 1
Derivatives, Fair Value [Line Items]
Derivative asset, gross		25		25		9
Derivative liability, gross		33		33		13
Fair Value Measured on a Recurring Basis | Level 2
Derivatives, Fair Value [Line Items]
Derivative asset, gross		74		74		46
Derivative liability, gross		102		102		62
Fair Value Measured on a Recurring Basis | Level 3
Derivatives, Fair Value [Line Items]
Derivative asset, gross		171		171		52
Derivative liability, gross		13		13		5
Changes in Level 3 Commodity Derivatives [Roll Forward]
Transfers level 3, net			$ 0	0
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		140		140		71
Netting, asset		(98)		(98)		(53)	[3]
Derivative Asset, Noncurrent		74		74		33
Derivative liability, gross		141		141		75
Netting, liability		(100)		(100)		(58)	[3]
Derivative liability		41		41		17
Derivative Liability, Noncurrent		73		73		36
Changes in Level 3 Commodity Derivatives [Roll Forward]
Derivative Asset, Current		42		42		18
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross	[4]	124		124		30
Netting, asset	[4]	(4)		(4)		(1)	[3]
Derivative liability, gross	[4]	4		4		1
Netting, liability	[4]	(4)		(4)		(1)	[3]
Derivative liability	[4]	0		0		0
Changes in Level 3 Commodity Derivatives [Roll Forward]
Derivative Asset, Current	[4]	120		120		29
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross		6		6		6
Netting, asset		0		0		0	[3]
Derivative liability, gross		3		3		4
Netting, liability		0		0		0	[3]
Derivative liability		3		3		4
Changes in Level 3 Commodity Derivatives [Roll Forward]
Derivative Asset, Current		6		6		6
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 1 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		25		25		9
Derivative liability, gross		33		33		13
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 1 | Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross	[4]	0		0		0
Derivative liability, gross	[4]	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		68		68		40
Derivative liability, gross		99		99		58
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 2 | Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross	[4]	0		0		0
Derivative liability, gross	[4]	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		6		6		6
Derivative liability, gross		3		3		4
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 3 | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		47		47		22
Derivative liability, gross		9		9		4
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Level 3 | Electric Commodity
Derivatives, Fair Value [Line Items]
Derivative asset, gross	[4]	124		124		30
Derivative liability, gross	[4]	4		4		1
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 | Other Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross		148		148		75
Netting, asset		(74)		(74)		(42)	[3]
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Level 1
Derivatives, Fair Value [Line Items]
Derivative asset, gross		30		30		6
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Level 2
Derivatives, Fair Value [Line Items]
Derivative asset, gross		42		42		34
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Level 3
Derivatives, Fair Value [Line Items]
Derivative asset, gross		76		76		35
Fair Value Measured on a Recurring Basis | Other Noncurrent Assets | Other Derivative Instruments | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative asset, gross		148		148		75
Netting, asset		(74)		(74)		(42)	[3]
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		30		30		6
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		42		42		34
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		76		76		35
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross		153		153		89
Netting, liability		(80)		(80)		(53)	[3]
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Level 1
Derivatives, Fair Value [Line Items]
Derivative liability, gross		50		50		15
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Level 2
Derivatives, Fair Value [Line Items]
Derivative liability, gross		61		61		48
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Level 3
Derivatives, Fair Value [Line Items]
Derivative liability, gross		42		42		26
Fair Value Measured on a Recurring Basis | Other Noncurrent Liabilities | Other Derivative Instruments | Commodity Trading
Derivatives, Fair Value [Line Items]
Derivative liability, gross		153		153		89
Netting, liability		(80)		(80)		(53)	[3]
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		50		50		15
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		61		61		48
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		26
Fair Value, Measurements, Nonrecurring | PPAs
Derivatives, Fair Value [Line Items]
Derivative liability	[5]	14		14		14
Derivative Liability, Noncurrent	[5]	$ 30		$ 30		$ 35
[1]Relates primarily to FTR instruments administered by MISO (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, changes in fair value are deferred as a regulatory asset or liability and do not have a material impact on net income.[2]Relates to commodity trading and is subject to offsetting losses of derivative instruments categorized as levels 1 and 2 in the consolidated income statement.[3]NSP-Minnesota nets derivative instruments and related collateral on its consolidated balance sheets when supported by a legally enforceable master netting agreement. At Sept. 30, 2022 and Dec. 31, 2021, derivatives include $2 million and no obligations to return cash collateral, respectively. At Sept. 30, 2022 and Dec. 31, 2021 derivative assets and liabilities include rights to reclaim cash collateral of $9 million and $16 million, respectively. Counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.[4]Amounts relate to FTR instruments administered by MISO (annual auctions occurring in the second quarter). These instruments are utilized/intended to offset the impacts of transmission system congestion. Higher congestion costs have led to an increase in the fair value of FTRs. Due to regulatory recovery, fair values for FTRs are offset/deferred as a regulatory asset or liability and do not have a material impact on net income.[5]During 2006, Xcel Energy qualified these contracts under the normal purchase exception. Based on this qualification, the contracts are no longer adjusted to fair value and the previous carrying value of these contracts will be 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	Sep. 30, 2022	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying amount	$ 6,941	$ 6,747
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 5,881	$ 7,761

Benefit Plans and Other Postr_3

Benefit Plans and Other Postretirement Benefits (Details) $ in Millions		1 Months Ended	3 Months Ended		9 Months Ended
		Jan. 31, 2022 USD ($) Plan	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)
Pension Plan [Member]
Components of Net Periodic Benefit Cost [Abstract]
Service Cost			$ 6	$ 7	$ 20	$ 22
Interest cost (a)	[1]		7	7	19	19
Expected return on plan assets (a)	[1]		(12)	(13)	(36)	(39)
Amortization of prior service credit (a)	[1]		0	0	0	0
Amortization of net loss (a)	[1]		6	9	18	26
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	[2]		29	23	28	23
Net periodic benefit cost			36	33	49	51
Effects of regulation			(32)	(28)	(31)	(30)
Net benefit cost recognized for financial reporting			4	5	18	21
Total contributions to the pension plans during the period		$ 5
Pension Plan [Member] | Xcel Energy Inc.
Components of Net Periodic Benefit Cost [Abstract]
Total contributions to the pension plans during the period		$ 50
Number of Xcel Energy's pension plans to which contributions were made | Plan		4
Other Postretirement Benefits Plan [Member]
Components of Net Periodic Benefit Cost [Abstract]
Service Cost			0	0	0	0
Interest cost (a)	[1]		0	0	1	1
Expected return on plan assets (a)	[1]		0	0	0	0
Amortization of prior service credit (a)	[1]		(1)	0	(2)	(2)
Amortization of net loss (a)	[1]		1	0	1	1
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement			0	0	0	0
Net periodic benefit cost			0	0	0	0
Effects of regulation			0	0	0	0
Net benefit cost recognized for financial reporting			$ 0	$ 0	$ 0	$ 0
[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.[2]A settlement charge is required when the amount of all 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 third quarter of 2022 and 2021 as a result of lump-sum distributions during the 2022 and 2021 plan years, NSP-Minnesota recorded pension settlement charges of $29 million and $23 million, respectively, which were not recognized in earnings due to the effects of rate making.

Commitments and Contingencies -

Commitments and Contingencies - Sherco (Details) $ in Millions	1 Months Ended
	Jan. 31, 2021 USD ($)
Rate Matters [Abstract]
Customer refund of previously recovered purchased power costs	$ 17
Amount MPUC previously disallowed related to Sherco outage	$ 22

Commitments and Contingencies_2

Commitments and Contingencies - MISO ROE Complaints (Details) - Federal Energy Regulatory Commission (FERC) - FERC Proceeding, MISO ROE Complaint - NSP Minnesota and NSP Wisconsin [Member] [Member]	1 Months Ended
	Feb. 28, 2015	Nov. 30, 2013
Public Utilities, General Disclosures [Line Items]
Public Utilities, Base Return On Equity Charged To Customers Through Transmission Formula Rates	12.38%	12.38%
Public Utilities, ROE Applicable To Transmission Formula Rates In The MISO Region, Recommended By Third Parties	8.67%	9.15%

Commitments and Contingencies_3

Commitments and Contingencies - Environmental, MGP, Landfill or Disposal Sites (Details)	Sep. 30, 2022
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_4

Commitments and Contingencies - Environmental Requirements - Water and Waste (Details) $ in Millions	Sep. 30, 2022 USD ($)
Federal Coal Ash Regulation
Site Contingency [Line Items]
Number of sites where regulated ash units will still be in operation at a specified date	3
Federal Clean Water Act Section 316 (b) | Capital Addition Purchase Commitments
Site Contingency [Line Items]
Liability for estimated cost to comply with regulation	$ 36

Commitments and Contingencies_5

Commitments and Contingencies - Leases (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2022		Sep. 30, 2021		Sep. 30, 2022		Sep. 30, 2021		Dec. 31, 2021
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	$ 27	[1]	$ 18	[1]	$ 80	[2]	$ 59	[2]
Lessee, Operating Lease, Liability, to be Paid	409				409
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(32)				(32)
Operating Lease, Liability	377				377
Operating Lease, Liability, Current	(97)				(97)				$ (90)
Operating lease liabilities	280				280				$ 353
Short-term Lease, Cost	1				2		1
Purchased Power Agreements
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	25		17		74		53
Lessee, Operating Lease, Liability, to be Paid	342				342
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(22)				(22)
Operating Lease, Liability	320				320
Property, Plant and Equipment, Other Types
Lessee, Lease, Description [Line Items]
Operating Lease, Cost	2	[3]	$ 1	[3]	6	[4]	$ 6	[4]
Lessee, Operating Lease, Liability, to be Paid	67				67
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(10)				(10)
Operating Lease, Liability	$ 57				$ 57
[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.[2]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.[3] Includes $1 million and $0 million of short-term lease expense for 2022 and 2021, respectively. Includes short-term lease expen se of $2 million fo r 2022 and $1 million for 2021.

Commitments and Contingencies_6

Commitments and Contingencies - Variable Interest Entities (Details) - MW	Sep. 30, 2022	Dec. 31, 2021
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Variable Interest Entity [Line Items]
Generating capacity under long term purchased power agreements	1,322	1,347

Other Comprehensive Income (L_3

Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income at beginning of period				$ 7,573
Accumulated other comprehensive (loss) income at end of period		$ 7,635		7,635
Income Tax Expense (Benefit)		12	$ 15	(70)	$ (17)
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		(17)	(18)	(17)	(19)
Accumulated other comprehensive (loss) income at end of period		(17)	(18)	(17)	(18)
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	[1]	0	0	0	1
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		(3)	(3)	(3)	(3)
Accumulated other comprehensive (loss) income at end of period		(3)	(3)	(3)	(3)
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	[1]	0	0	0	0
Total
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income at beginning of period		(20)	(21)	(20)	(22)
Accumulated other comprehensive (loss) income at end of period		(20)	(21)	(20)	(21)
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	[1]	$ 0	$ 0	$ 0	$ 1
[1]Included in interest charges

Segment Information (Details)

Segment Information (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2022		Sep. 30, 2021		Sep. 30, 2022		Sep. 30, 2021
Segment Reporting Information [Line Items]
Net income	$ 269		$ 248		$ 514		$ 489
Natural gas	102		70		703		353
Other	12		10		33		29
Regulated and Unregulated Operating Revenue	1,844		1,557		5,044		4,224
Affiliate Revenue	132		127		394		373
Total revenues
Segment Reporting Information [Line Items]
Regulated and Unregulated Operating Revenue	1,844	[1],[2]	1,558	[1],[2]	5,045	[3],[4]	4,225	[3],[4]
Intersegment Eliminations
Segment Reporting Information [Line Items]
Regulated and Unregulated Operating Revenue	0		(1)		(1)		(1)
Regulated Electric
Segment Reporting Information [Line Items]
Net income	275		245		486		464
Revenues Including Intersegment Revenues	1,730		1,477		4,308		3,842
Regulated Natural Gas
Segment Reporting Information [Line Items]
Net income	(12)		(2)		21		18
Revenues Including Intersegment Revenues	102		71		704		354
Regulated Natural Gas | Total revenues
Segment Reporting Information [Line Items]
Natural gas	102	[2]	70	[2]	703	[4]	353	[4]
Regulated Natural Gas | Intersegment Eliminations
Segment Reporting Information [Line Items]
Natural gas	0		1		1		1
All Other
Segment Reporting Information [Line Items]
Net income	6		5		7		7
All Other | Total revenues
Segment Reporting Information [Line Items]
Other	$ 12		$ 10		$ 33		$ 29
[1]Operating revenues include $132 million and $127 million of affiliate electric revenue for the three months ended Sept. 30, 2022 and 2021.[2]Operating revenues include an immaterial amount of affiliate gas revenue for the three months ended Sept. 30, 2022 and 2021.[3]Operating revenues include $394 million and $373 million of affiliate electric revenue for the nine months ended Sept. 30, 2022 and 2021.[4]Operating revenues include an immaterial amount of affiliate gas revenue for the nine months ended Sept. 30, 2022 and 2021.