XML 49 R57.htm IDEA: XBRL DOCUMENT
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Financing (Details) (USD $) | 12 Months Ended | 0 Months Ended |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Apr. 03, 2013 | Sep. 30, 2011 | Dec. 27, 2012 | Apr. 22, 2013 | Mar. 05, 2014 | Dec. 22, 2014 | Mar. 06, 2013 | Dec. 14, 2012 | Sep. 30, 2012 | Dec. 09, 2013 | Feb. 20, 2015
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repayments of Unsecured Debt |  | $ 26,900,000us-gaap_RepaymentsOfUnsecuredDebt |  |  |  |  |  |  |  |  |  |  |  |
Loss on reacquired debt | 0us-gaap_GainsLossesOnExtinguishmentOfDebt | 3,253,000us-gaap_GainsLossesOnExtinguishmentOfDebt | 0us-gaap_GainsLossesOnExtinguishmentOfDebt |  |  |  |  |  |  |  |  |  |  |
Short-term debt | 105,600,000us-gaap_ShortTermBorrowings | 149,200,000us-gaap_ShortTermBorrowings |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from Short-term Debt |  |  | 100,000,000us-gaap_ProceedsFromShortTermDebt |  |  |  |  |  |  |  |  |  |  |
Long-term Debt | 1,975,090,000us-gaap_LongTermDebt | 1,745,420,000us-gaap_LongTermDebt |  |  |  |  |  |  |  |  |  |  |  |
Unsecured Debt [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 9.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_LongtermDebtTypeAxis = us-gaap_UnsecuredDebtMember |  |  |  |  |  |  |  |  |  |  |  |
Public Service Company of New Mexico [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term Debt | 1,490,657,000us-gaap_LongTermDebt / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | 1,290,618,000us-gaap_LongTermDebt / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  |  |  |  |  |  |  |  |  |  |  |
Short-term debt - affiliate | 0us-gaap_NotesPayableRelatedPartiesClassifiedCurrent / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | 32,500,000us-gaap_NotesPayableRelatedPartiesClassifiedCurrent / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  |  |  |  |  |  |  |  |  |  |  |
Public Service Company of New Mexico [Member] | Unsecured Debt [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Shelf Registration Statement for Unsecured Debt | 500,000,000pnm_DebtInstrumentShelfRegistrationStatementForUnsecuredDebt / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember / us-gaap_LongtermDebtTypeAxis = us-gaap_UnsecuredDebtMember |  |  |  |  |  |  |  |  |  |  |  |  |
Public Service Company of New Mexico [Member] | PNM 2014 Term Loan Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term Debt |  |  |  |  |  |  |  | 175,000,000us-gaap_LongTermDebt / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember / us-gaap_LongtermDebtTypeAxis = pnm_PNM2014TermLoanAgreementMember |  |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | 1.11%us-gaap_DebtInstrumentInterestRateEffectivePercentage / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember / us-gaap_LongtermDebtTypeAxis = pnm_PNM2014TermLoanAgreementMember |  |  |  |  |  |  |  |  |  |  |  |  |
Public Service Company of New Mexico [Member] | PNM 2014 Multi-Draw Term Loan Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term Debt |  |  |  |  |  |  |  |  | 125,000,000us-gaap_LongTermDebt / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember / us-gaap_LongtermDebtTypeAxis = pnm_PNM2014MultiDrawTermLoanAgreementMember |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | 0.75%us-gaap_DebtInstrumentInterestRateEffectivePercentage / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember / us-gaap_LongtermDebtTypeAxis = pnm_PNM2014MultiDrawTermLoanAgreementMember |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from (Repayments of) Debt | 100,000,000us-gaap_ProceedsFromRepaymentsOfDebt / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember / us-gaap_LongtermDebtTypeAxis = pnm_PNM2014MultiDrawTermLoanAgreementMember |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Unused Borrowing Capacity, Amount | 25,000,000us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember / us-gaap_LongtermDebtTypeAxis = pnm_PNM2014MultiDrawTermLoanAgreementMember |  |  |  |  |  |  |  |  |  |  |  |  |
Texas-New Mexico Power Company [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  |  |  |  |  |  |  |  |  | 1,000us-gaap_DebtInstrumentFaceAmount / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  |  |  |
Long-term Debt | 365,667,000us-gaap_LongTermDebt / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | 336,036,000us-gaap_LongTermDebt / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Cash Offered for Debt Exchanged |  |  |  |  |  |  |  |  |  | 140pnm_DebtInstrumentCashOfferedforDebtExchanged / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  |  |  |
Repayments of Debt | 30,000,000us-gaap_RepaymentsOfDebt / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  |  |  |  |  |  |  |  |  |  |  |  |
Short-term debt - affiliate | 22,700,000us-gaap_NotesPayableRelatedPartiesClassifiedCurrent / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | 29,400,000us-gaap_NotesPayableRelatedPartiesClassifiedCurrent / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  |  |  |  |  |  |  |  |  |  |  |
Texas-New Mexico Power Company [Member] | First Mortgage Bonds [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Cash Paid for Debt Exchanged |  |  |  | 13,000,000pnm_DebtInstrumentCashPaidForDebtExchanged / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_FirstMortgageBondsMember |  |  |  |  |  |  |  |  |  |
Texas-New Mexico Power Company [Member] | 2011 Term Loan Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from Bank Debt |  |  |  |  | 50,000,000us-gaap_ProceedsFromBankDebt / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_A2011TermLoanAgreementMember |  |  |  |  |  |  |  |  |
Repayments of Debt | 50,000,000us-gaap_RepaymentsOfDebt / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_A2011TermLoanAgreementMember |  |  |  |  |  |  |  |  |  |  |  |  |
Senior unsecured notes, 9.25% due 2015 [Member] | Senior unsecured notes, 9.25% due 2015 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  | 23,800,000us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = pnm_SeniorUnsecuredNoteDue2015At9Point25PercentMember / us-gaap_LongtermDebtTypeAxis = pnm_SeniorUnsecuredNoteDue2015At9Point25PercentMember |  |  |  |  |  |  |  |  |  |  |  |
PNMR Term Loan Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Short-term debt | 100,000,000us-gaap_ShortTermBorrowings / us-gaap_DebtInstrumentAxis = pnm_PnmrTermLoanAgreementMember | 100,000,000us-gaap_ShortTermBorrowings / us-gaap_DebtInstrumentAxis = pnm_PnmrTermLoanAgreementMember |  |  |  |  |  |  |  |  |  |  |  |
PNMR Term Loan Agreement [Member] | Notes Payable to Banks [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Short-term debt |  |  |  |  |  |  |  |  |  |  | 100,000,000us-gaap_ShortTermBorrowings / us-gaap_DebtInstrumentAxis = pnm_PnmrTermLoanAgreementMember / us-gaap_ShortTermDebtTypeAxis = us-gaap_NotesPayableToBanksMember |  |  |
Proceeds from Short-term Debt |  |  |  |  |  | 100,000,000us-gaap_ProceedsFromShortTermDebt / us-gaap_DebtInstrumentAxis = pnm_PnmrTermLoanAgreementMember / us-gaap_ShortTermDebtTypeAxis = us-gaap_NotesPayableToBanksMember |  |  |  |  |  |  |  |
Repayments of Lines of Credit |  |  |  |  |  | 100,000,000us-gaap_RepaymentsOfLinesOfCredit / us-gaap_DebtInstrumentAxis = pnm_PnmrTermLoanAgreementMember / us-gaap_ShortTermDebtTypeAxis = us-gaap_NotesPayableToBanksMember |  |  |  |  |  |  |  |
2.54% Maturing of September First, 2042 with a Mandatory Tender on June First, 2017 [Member] | Public Service Company of New Mexico [Member] | Pollution Control Revenue Bonds [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  |  |  |  |  |  |  |  |  |  |  | 20,000,000us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = pnm_TwoPointFiveFourPercentMaturingOfSeptemberFirst2042WithMandatoryTenderOnJuneFirst2017Member / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember / us-gaap_LongtermDebtTypeAxis = us-gaap_BondsMember |  |
Debt Instrument, Interest Rate, Stated Percentage |  |  |  |  |  |  |  |  |  |  |  | 2.54%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = pnm_TwoPointFiveFourPercentMaturingOfSeptemberFirst2042WithMandatoryTenderOnJuneFirst2017Member / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember / us-gaap_LongtermDebtTypeAxis = us-gaap_BondsMember |  |
5.15% Percent Maturing in 2037 [Member] | Public Service Company of New Mexico [Member] | Pollution Control Revenue Bonds [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  |  |  |  |  |  |  |  |  |  |  | 5.15%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = pnm_FivePointOneFivePercentMaturingIn2037Member / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember / us-gaap_LongtermDebtTypeAxis = us-gaap_BondsMember |  |
Debt Instrument, Refunded Amount Redeemed at Par and Retired |  |  |  |  |  |  |  |  |  |  |  | 20,000,000pnm_DebtInstrumentRefundedAmountRedeemedAtParAndRetired / us-gaap_DebtInstrumentAxis = pnm_FivePointOneFivePercentMaturingIn2037Member / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember / us-gaap_LongtermDebtTypeAxis = us-gaap_BondsMember |  |
PNM Term Loan Agreement [Member] | Notes Payable to Banks [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Short-term debt |  |  |  |  |  |  | 75,000,000us-gaap_ShortTermBorrowings / us-gaap_DebtInstrumentAxis = pnm_PnmTermLoanAgreementMember / us-gaap_ShortTermDebtTypeAxis = us-gaap_NotesPayableToBanksMember |  |  |  |  |  |  |
Repayments of Lines of Credit |  |  |  |  |  |  | 75,000,000us-gaap_RepaymentsOfLinesOfCredit / us-gaap_DebtInstrumentAxis = pnm_PnmTermLoanAgreementMember / us-gaap_ShortTermDebtTypeAxis = us-gaap_NotesPayableToBanksMember |  |  |  |  |  |  |
First Mortgage Bonds Due 2014, Series 2009A, at 9 point 50 percent [Member] | Texas-New Mexico Power Company [Member] | First Mortgage Bonds [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  |  |  |  |  |  |  |  |  | 265,500,000us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBondsDue2014Series2009AAt9Point50PercentMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_FirstMortgageBondsMember |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage | 9.50%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBondsDue2014Series2009AAt9Point50PercentMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_FirstMortgageBondsMember | 9.50%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBondsDue2014Series2009AAt9Point50PercentMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_FirstMortgageBondsMember |  | 9.50%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBondsDue2014Series2009AAt9Point50PercentMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_FirstMortgageBondsMember |  |  |  |  |  | 9.50%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBondsDue2014Series2009AAt9Point50PercentMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_FirstMortgageBondsMember |  |  |  |
First Mortgage Bonds 6 Point 95 Percent, due 2043, Series 2013A [Member] | Texas-New Mexico Power Company [Member] | First Mortgage Bonds [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  |  |  | 93,200,000us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBonds6Point95PercentDue2043Series2013AMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_FirstMortgageBondsMember |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage | 6.95%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBonds6Point95PercentDue2043Series2013AMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_FirstMortgageBondsMember | 6.95%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBonds6Point95PercentDue2043Series2013AMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_FirstMortgageBondsMember |  | 6.95%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBonds6Point95PercentDue2043Series2013AMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_FirstMortgageBondsMember |  |  |  |  |  | 6.95%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBonds6Point95PercentDue2043Series2013AMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_FirstMortgageBondsMember |  |  |  |
Debt Instrument, Unamortized Premium |  |  |  | 23,200,000us-gaap_DebtInstrumentUnamortizedPremium / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBonds6Point95PercentDue2043Series2013AMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_FirstMortgageBondsMember |  |  |  |  |  |  |  |  |  |
First Mortgage Bonds Due 2024, Series 2014A, at 4 point 03 percent [Member] [Member] | Texas-New Mexico Power Company [Member] | Pollution Control Revenue Bonds [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  |  |  |  |  |  |  |  |  |  |  |  | 80,000,000us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBondsDue2024Series2014Aat4point03percentMemberMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = us-gaap_BondsMember |
Debt Instrument, Interest Rate, Stated Percentage |  |  |  |  |  |  |  |  |  |  |  |  | 4.03%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBondsDue2024Series2014Aat4point03percentMemberMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = us-gaap_BondsMember |
First Mortgage Bonds Due 2024, Series 2014A, at 4 point 03 percent [Member] [Member] | Texas-New Mexico Power Company [Member] | First Mortgage Bonds [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage | 4.03%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = pnm_FirstMortgageBondsDue2024Series2014Aat4point03percentMemberMember / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_FirstMortgageBondsMember |  |  |  |  |  |  |  |  |  |  |  |  |
Borrowings from PNMR [Member] | Public Service Company of New Mexico [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Short-term debt - affiliate |  |  |  |  |  |  |  |  |  |  |  |  |  | 0us-gaap_NotesPayableRelatedPartiesClassifiedCurrent / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember / us-gaap_SubsequentEventTypeAxis = pnm_BorrowingsFromPnmrMember
Borrowings from PNMR [Member] | Texas-New Mexico Power Company [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Short-term debt - affiliate |  |  |  |  |  |  |  |  |  |  |  |  |  | 17,300,000us-gaap_NotesPayableRelatedPartiesClassifiedCurrent / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_SubsequentEventTypeAxis = pnm_BorrowingsFromPnmrMember
Subsequent Event [Member] | Public Service Company of New Mexico [Member] | PNM 2014 Multi-Draw Term Loan Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Unused Borrowing Capacity, Amount |  |  |  |  |  |  |  |  |  |  |  |  |  | 25,000,000us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember / us-gaap_LongtermDebtTypeAxis = pnm_PNM2014MultiDrawTermLoanAgreementMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Short-term debt - affiliate | 100,000,000us-gaap_NotesPayableRelatedPartiesClassifiedCurrent / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  |  |  |  |  |  |
Fair Value, Inputs, Level 2 [Member] | Cash Flow Hedging [Member] | Texas-New Mexico Power Company [Member] | 2011 Term Loan Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest Rate Derivative Liabilities, at Fair Value |  | $ 200,000us-gaap_InterestRateDerivativeLiabilitiesAtFairValue / us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis = us-gaap_CashFlowHedgingMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember / us-gaap_LongtermDebtTypeAxis = pnm_A2011TermLoanAgreementMember |  |  |  |  |  |  |  |  |  |  |  |

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- Definition Debt Instrument, Cash Offered for Debt Exchanged + References No definition available. + Details
Name: | pnm_DebtInstrumentCashOfferedforDebtExchanged
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Definition Debt Instrument, Cash Paid for Debt Exchanged + References No definition available. + Details
Name: | pnm_DebtInstrumentCashPaidForDebtExchanged
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Definition Debt Instrument, Refunded Amount Redeemed at Par and Retired + References No definition available. + Details
Name: | pnm_DebtInstrumentRefundedAmountRedeemedAtParAndRetired
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition Debt Instrument, Shelf Registration Statement for Unsecured Debt + References No definition available. + Details
Name: | pnm_DebtInstrumentShelfRegistrationStatementForUnsecuredDebt
Namespace Prefix: | pnm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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