XML 88 R69.htm IDEA: XBRL DOCUMENT
v3.22.2

Financing - Financing Activities (Details) |  |  |  |  |  |  | 3 Months Ended | 6 Months Ended |  |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
May 20, 2022 USD ($) | May 02, 2022 USD ($) derivative | Jan. 24, 2022 USD ($) | Jul. 14, 2021 USD ($) | Mar. 09, 2021 USD ($) | Dec. 22, 2020 USD ($) | Mar. 31, 2022 USD ($) | Jun. 30, 2022 USD ($) | Jul. 29, 2022 USD ($) | Jun. 01, 2022 USD ($) | May 05, 2022 | Apr. 27, 2022 USD ($) bond | Jan. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Aug. 16, 2021 USD ($) | May 18, 2021 USD ($) | Mar. 09, 2018 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Financing capacity |  |  |  |  |  |  |  |  |  |  |  |  | $ 40,000,000 |  |  |  |
Subsequent event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining borrowing capacity |  |  |  |  |  |  |  |  | $ 644,100,000 |  |  |  |  |  |  |  |
Variable Rate Debt | Interest rate contract | Cash Flow Hedge |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of instruments held | derivative |  | 2 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term of loan | 19 months | 20 months |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative, notional amount | $ 100,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fixed interest rate | 2.52% | 2.65% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative instruments in hedges, fair value |  |  |  |  |  |  |  | $ 2,300,000 |  |  |  |  |  |  |  |  |
Variable Rate Debt, Tranche 1 | Interest rate contract | Cash Flow Hedge |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative asset, notional amount |  | $ 150,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable Rate Debt, Tranche 2 | Interest rate contract | Cash Flow Hedge |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative asset, notional amount |  | $ 200,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
PNMR 2020 Delayed-Draw Term Loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  | $ 300,000,000 |  |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of debt |  |  |  |  |  | $ 80,000,000 |  |  |  |  |  |  |  |  |  |  |
Remaining borrowing capacity |  |  |  |  | $ 220,000,000 |  |  |  |  |  |  |  |  |  |  |  |
PNM |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity term over which financings require regulator approval (more than) |  |  |  |  |  |  |  | 18 months |  |  |  |  |  |  |  |  |
PNM | Subsequent event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining borrowing capacity |  |  |  |  |  |  |  |  | 320,100,000 |  |  |  |  |  |  |  |
Texas-New Mexico Power Company | Subsequent event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining borrowing capacity |  |  |  |  |  |  |  |  | $ 65,000,000 |  |  |  |  |  |  |  |
Line of credit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ratio of debt to capital (less than or equal to) |  |  |  |  |  |  |  | 70.00% |  |  |  |  |  |  |  |  |
Line of credit | PNMR 2021 Delayed-Draw Term Loan | Revolving credit facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Financing capacity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,000,000,000 |
Proceeds from long-term lines of credit |  |  | $ 100,000,000 |  |  |  | $ 900,000,000 |  |  |  |  |  |  |  |  |  |
Line of credit | PNM and TNMP |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ratio of debt to capital (less than or equal to) |  |  |  |  |  |  |  | 65.00% |  |  |  |  |  |  |  |  |
Bonds | PNMR 2021 Delayed-Draw Term Loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable interest rate |  |  |  |  |  |  |  | 2.56% |  |  |  |  |  |  |  |  |
Bonds | PNM | PNM 2021 75 Million Term Loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable interest rate |  |  |  |  |  |  |  | 2.45% |  |  |  |  |  |  |  |  |
Bonds | PNM | Pollution Control Revenue Bonds |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  |  |  | $ 31,500,000 |  |  |  | $ 104,500,000 |  |  |
Bonds | PNM | Pollution Control Revenue Bonds Due June Twenty Thirty Eight |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 36,000,000 |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.05% |  |  |
Bonds | PNM | Pollution Control Revenue Bonds Due June Twenty Forty |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 37,000,000 |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  | 2.125% |  |  |
Bonds | PNM | Pollution Control Revenue Bonds Due June Twenty Forty, City Of Farmington, NM |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 11,500,000 |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.20% |  |  |
Bonds | PNM | Pollution Control Revenue Bonds Due June Twenty Forty Two |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 20,000,000 |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  | 2.45% |  |  |
Bonds | PNM | Pollution Control Revenue Bonds Due June Twenty Twenty Four |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  | 3.00% |  |  |  |  |  |
Bonds | Texas-New Mexico Power Company | TNMP 2022 Bond Purchase Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  | $ 160,000,000 |  |  |  |  |
Debt instrument, series of bond issuance | bond |  |  |  |  |  |  |  |  |  |  |  | 2 |  |  |  |  |
Bonds | Texas-New Mexico Power Company | TNMP 2022 Bond Purchase Agreement at 4.13% Due May 12, 2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  | $ 65,000,000 |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  | 4.13% |  |  |  |  |
Bonds | Texas-New Mexico Power Company | TNMP 2022 Bond Purchase Agreement at 3.81% Due July 28, 2032 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  | $ 95,000,000 |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  | 3.81% |  |  |  |  |
Unsecured Debt | PNMR 2018 SUNS 3.25% due March 2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 300,000,000
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.25%
Repayments of debt |  |  |  |  | $ 80,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Mortgage Bonds | Texas-New Mexico Power Company | TNMP 2021 Bond Purchase Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  | $ 65,000,000 |  |  |  |  |  |  |  |  |  |  | $ 65,000,000 |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2.44% |  |
Senior Notes | PNM | PNM 2021 Note Purchase Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  | 160,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes | PNM | PNM 2021 SUNs At 2.59 Percent Due July 15, 2033 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  | $ 80,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate |  |  |  | 2.59% |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes | PNM | PNM 2021 SUNs At 3.14 Percent Due July 15, 2041 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  | $ 80,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate |  |  |  | 3.14% |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes | PNM | PNM 2021 SUNs At 5.35 Percent Due October 1, 2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  | $ 160,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate |  |  |  | 5.35% |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes | PNM | PNM 2019 40 Million Term Loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repayments of debt |  |  |  | $ 40,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Term loan agreement with banks | PNM | PNM 2021 75 Million Term Loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  | $ 75,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Debt Instrument, Covenant, Debt To Capitalization Ratio + References No definition available. + Details
Name: | pnm_DebtInstrumentCovenantDebtToCapitalizationRatio
Namespace Prefix: | pnm_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Series Of Bond Issuance + References No definition available. + Details
Name: | pnm_DebtInstrumentSeriesOfBondIssuance
Namespace Prefix: | pnm_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Public Utilities, Maturity Term Over Which Financings Require Regulator Approval + References No definition available. + Details
Name: | pnm_PublicUtilitiesMaturityTermOverWhichFinancingsRequireRegulatorApproval
Namespace Prefix: | pnm_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI https://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 50 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69C -URI https://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69B -URI https://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=123466204&loc=SL6036836-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 50 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal or face amount used to calculate payments on the derivative asset. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959 + Details
Name: | us-gaap_DerivativeAssetNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of derivative instruments of a particular derivative asset or group of derivative assets held by the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959 + Details
Name: | us-gaap_DerivativeAssetNumberOfInstrumentsHeld
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fixed interest rate related to the interest rate derivative. + References No definition available. + Details
Name: | us-gaap_DerivativeFixedInterestRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate fair value of all derivative assets designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations. + References No definition available. + Details
Name: | us-gaap_DerivativeInstrumentsInHedgesAssetsAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959 + Details
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI https://asc.fasb.org/extlink&oid=123466204&loc=SL6031897-161870 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69C -URI https://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69B -URI https://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1D -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash inflow from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromLongTermLinesOfCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3291-108585 + Details
Name: | us-gaap_RepaymentsOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_VariableRateDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_VariableRateDebtTranche1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_VariableRateDebtTranche2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PNMR2020DelayedDrawTermLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=pnm_PublicServiceCompanyOfNewMexicoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=pnm_TexasNewMexicoPowerCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PNMR2021DelayedDrawTermLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=pnm_PNMAndTNMPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_NotesPayableOtherPayablesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PNM202175MillionTermLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PollutionControlRevenueBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PollutionControlRevenueBondsDueJuneTwentyThirtyEightMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PollutionControlRevenueBondsDueJuneTwentyForty1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PollutionControlRevenueBondsDueJuneTwentyForty2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PollutionControlRevenueBondsDueJuneTwentyFortyTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PollutionControlRevenueBondsDueJuneTwentyTwentyFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_TNMP2022BondPurchaseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_TNMP2022BondPurchaseAgreementAt413DueMay122022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_TNMP2022BondPurchaseAgreementAt381DueJuly282032Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PNMR2018SUNS3.25percentdueMarch2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_SecuredDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_TNMP2021BondPurchaseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PNM2021NotePurchaseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PNM2021SUNsAt259PercentDueJuly152033Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PNM2021SUNsAt314PercentDueJuly152041Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PNM2021SUNsAt535PercentDueOctober12021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=pnm_PNM201940MillionTermLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_NotesPayableToBanksMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |