XML 50 R76.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Income Taxes Schedule of Deferred Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013
--- | --- | ---
Deferred tax assets: |  |
Net operating loss | $ 153,858us-gaap_DeferredTaxAssetsOperatingLossCarryforwards | $ 134,418us-gaap_DeferredTaxAssetsOperatingLossCarryforwards
Regulatory liabilities related to income taxes | 78,858us-gaap_DeferredTaxAssetsRegulatoryAssetsAndLiabilities | 83,838us-gaap_DeferredTaxAssetsRegulatoryAssetsAndLiabilities
Deferred Tax Assets, Tax Credit Carryforwards | 54,748us-gaap_DeferredTaxAssetsTaxCreditCarryforwards | 40,708us-gaap_DeferredTaxAssetsTaxCreditCarryforwards
Other | 68,566us-gaap_DeferredTaxAssetsOther | 75,832us-gaap_DeferredTaxAssetsOther
Total deferred tax assets | 356,030us-gaap_DeferredTaxAssetsGross | 334,796us-gaap_DeferredTaxAssetsGross
Deferred tax liabilities: |  |
Depreciation and plant related | (914,926)us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment | (814,671)us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment
Investment tax credit | (36,790)pnm_DeferredTaxLiabilitiesInvestmentTaxCredit | (25,855)pnm_DeferredTaxLiabilitiesInvestmentTaxCredit
Regulatory assets related to income taxes | (67,910)us-gaap_DeferredTaxLiabilitiesRegulatoryAssetsAndLiabilities | (66,352)us-gaap_DeferredTaxLiabilitiesRegulatoryAssetsAndLiabilities
Stranded costs | (19,352)pnm_DeferredTaxLiabilitiesStrandedCosts | (22,262)pnm_DeferredTaxLiabilitiesStrandedCosts
Pension | (66,498)pnm_DeferredTaxLiabilitiesCompensationandBenefitsPensions | (58,780)pnm_DeferredTaxLiabilitiesCompensationandBenefitsPensions
Other | (115,282)us-gaap_DeferredTaxLiabilitiesOther | (115,458)us-gaap_DeferredTaxLiabilitiesOther
Total deferred tax liabilities | (1,220,758)us-gaap_DeferredIncomeTaxLiabilities | (1,103,378)us-gaap_DeferredIncomeTaxLiabilities
Current accumulated deferred income tax (asset) liability | (864,728)us-gaap_DeferredTaxLiabilities | (768,582)us-gaap_DeferredTaxLiabilities
Deferred Tax Assets (Liabilities), Net [Abstract] |  |
Current accumulated deferred income tax (asset) liability | (26,383)us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent | (58,681)us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent
Non-current accumulated deferred income tax liability | (891,111)us-gaap_DeferredTaxLiabilitiesNoncurrent | (827,263)us-gaap_DeferredTaxLiabilitiesNoncurrent
Public Service Company of New Mexico [Member] |  |
Deferred tax assets: |  |
Net operating loss | 108,505us-gaap_DeferredTaxAssetsOperatingLossCarryforwards / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | 99,247us-gaap_DeferredTaxAssetsOperatingLossCarryforwards / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Regulatory liabilities related to income taxes | 74,293us-gaap_DeferredTaxAssetsRegulatoryAssetsAndLiabilities / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | 78,849us-gaap_DeferredTaxAssetsRegulatoryAssetsAndLiabilities / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Deferred Tax Assets, Tax Credit Carryforwards | 35,259us-gaap_DeferredTaxAssetsTaxCreditCarryforwards / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | 22,509us-gaap_DeferredTaxAssetsTaxCreditCarryforwards / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Other | 35,681us-gaap_DeferredTaxAssetsOther / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | 37,008us-gaap_DeferredTaxAssetsOther / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Total deferred tax assets | 253,738us-gaap_DeferredTaxAssetsGross / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | 237,613us-gaap_DeferredTaxAssetsGross / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Deferred tax liabilities: |  |
Depreciation and plant related | (733,519)us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | (661,239)us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Investment tax credit | (36,790)pnm_DeferredTaxLiabilitiesInvestmentTaxCredit / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | (25,855)pnm_DeferredTaxLiabilitiesInvestmentTaxCredit / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Regulatory assets related to income taxes | (57,637)us-gaap_DeferredTaxLiabilitiesRegulatoryAssetsAndLiabilities / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | (55,844)us-gaap_DeferredTaxLiabilitiesRegulatoryAssetsAndLiabilities / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Pension | (58,474)pnm_DeferredTaxLiabilitiesCompensationandBenefitsPensions / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | (52,104)pnm_DeferredTaxLiabilitiesCompensationandBenefitsPensions / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Other | (70,714)us-gaap_DeferredTaxLiabilitiesOther / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | (75,838)us-gaap_DeferredTaxLiabilitiesOther / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Total deferred tax liabilities | (957,134)us-gaap_DeferredIncomeTaxLiabilities / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | (870,880)us-gaap_DeferredIncomeTaxLiabilities / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Current accumulated deferred income tax (asset) liability | (703,396)us-gaap_DeferredTaxLiabilities / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | (633,267)us-gaap_DeferredTaxLiabilities / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Deferred Tax Assets (Liabilities), Net [Abstract] |  |
Current accumulated deferred income tax (asset) liability | (12,418)us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | (43,827)us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Non-current accumulated deferred income tax liability | (715,814)us-gaap_DeferredTaxLiabilitiesNoncurrent / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | (677,094)us-gaap_DeferredTaxLiabilitiesNoncurrent / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Texas-New Mexico Power Company [Member] |  |
Deferred tax assets: |  |
Regulatory liabilities related to income taxes | 4,565us-gaap_DeferredTaxAssetsRegulatoryAssetsAndLiabilities / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | 4,988us-gaap_DeferredTaxAssetsRegulatoryAssetsAndLiabilities / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Other | 13,429us-gaap_DeferredTaxAssetsOther / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | 23,479us-gaap_DeferredTaxAssetsOther / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Total deferred tax assets | 17,994us-gaap_DeferredTaxAssetsGross / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | 28,467us-gaap_DeferredTaxAssetsGross / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Deferred tax liabilities: |  |
Depreciation and plant related | (174,510)us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | (151,581)us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Regulatory assets related to income taxes | (10,197)us-gaap_DeferredTaxLiabilitiesRegulatoryAssetsAndLiabilities / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | (10,509)us-gaap_DeferredTaxLiabilitiesRegulatoryAssetsAndLiabilities / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Loss on reacquired debt | (12,846)pnm_DeferredTaxLiabilityLossonreacquireddebt / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | (13,516)pnm_DeferredTaxLiabilityLossonreacquireddebt / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Stranded costs | (19,352)pnm_DeferredTaxLiabilitiesStrandedCosts / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | (22,262)pnm_DeferredTaxLiabilitiesStrandedCosts / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Other | (12,636)us-gaap_DeferredTaxLiabilitiesOther / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | (14,295)us-gaap_DeferredTaxLiabilitiesOther / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Total deferred tax liabilities | (229,541)us-gaap_DeferredIncomeTaxLiabilities / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | (212,163)us-gaap_DeferredIncomeTaxLiabilities / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Current accumulated deferred income tax (asset) liability | (211,547)us-gaap_DeferredTaxLiabilities / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | (183,696)us-gaap_DeferredTaxLiabilities / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Deferred Tax Assets (Liabilities), Net [Abstract] |  |
Current accumulated deferred income tax (asset) liability | (6,398)us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | (6,501)us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Non-current accumulated deferred income tax liability | $ (217,945)us-gaap_DeferredTaxLiabilitiesNoncurrent / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | $ (190,197)us-gaap_DeferredTaxLiabilitiesNoncurrent / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember

X
- Definition Deferred Tax Liabilities, Compensation and Benefits, Pensions + References No definition available. + Details
Name: | pnm_DeferredTaxLiabilitiesCompensationandBenefitsPensions
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Deferred Tax Liabilities, Investment Tax Credit + References No definition available. + Details
Name: | pnm_DeferredTaxLiabilitiesInvestmentTaxCredit
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Deferred Tax Liabilities, Stranded Costs + References No definition available. + Details
Name: | pnm_DeferredTaxLiabilitiesStrandedCosts
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Deferred Tax Liability, Loss on reacquired debt + References No definition available. + Details
Name: | pnm_DeferredTaxLiabilityLossonreacquireddebt
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_ComponentsOfDeferredTaxAssetsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ComponentsOfDeferredTaxLiabilitiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Deferred Tax Liability -URI http://asc.fasb.org/extlink&oid=6510232 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Subparagraph b(2) -Article 7 + Details
Name: | us-gaap_DeferredIncomeTaxLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Deferred Tax Asset -URI http://asc.fasb.org/extlink&oid=6510090 + Details
Name: | us-gaap_DeferredTaxAssetsGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_DeferredTaxAssetsLiabilitiesNetAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards, net of deferred tax liability attributable to taxable temporary differences expected to be realized or consumed within one year or operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=37586315&loc=d3e31917-109318 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=37586315&loc=d3e31931-109318 + Details
Name: | us-gaap_DeferredTaxAssetsLiabilitiesNetCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32621-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32632-109319 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 25 -Paragraph 20 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=29652012&loc=d3e28680-109314 + Details
Name: | us-gaap_DeferredTaxAssetsOperatingLossCarryforwards
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences not separately disclosed. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32621-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 25 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=29652012&loc=d3e28680-109314 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32632-109319 + Details
Name: | us-gaap_DeferredTaxAssetsOther
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences derived regulatory assets and liabilities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32621-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 25 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=29652012&loc=d3e28680-109314 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32632-109319 + Details
Name: | us-gaap_DeferredTaxAssetsRegulatoryAssetsAndLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The tax effect as of the balance sheet date of the amount of future tax deductions arising from all unused tax credit carryforwards which have been reduced by a valuation allowance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32621-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32632-109319 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Carryforwards -URI http://asc.fasb.org/extlink&oid=6506874 + Details
Name: | us-gaap_DeferredTaxAssetsTaxCreditCarryforwards
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences net of deferred tax asset attributable to deductible temporary differences and carryforwards after valuation allowances. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=37586315&loc=d3e31931-109318 + Details
Name: | us-gaap_DeferredTaxLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences, net of deferred tax asset attributable to deductible temporary differences and carryforwards net of valuation allowances expected to be realized or consumed after one year (or the normal operating cycle, if longer). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=37586315&loc=d3e31917-109318 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=37586315&loc=d3e31931-109318 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=37586315&loc=d3e31958-109318 + Details
Name: | us-gaap_DeferredTaxLiabilitiesNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences not separately disclosed. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32621-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 25 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=29652012&loc=d3e28680-109314 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32632-109319 + Details
Name: | us-gaap_DeferredTaxLiabilitiesOther
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32621-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 25 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=29652012&loc=d3e28680-109314 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32632-109319 + Details
Name: | us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences from regulatory assets and liabilities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32621-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 25 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=29652012&loc=d3e28680-109314 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32632-109319 + Details
Name: | us-gaap_DeferredTaxLiabilitiesRegulatoryAssetsAndLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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: |