XML 102 R79.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Income Taxes Interest Income (Expense) Related to Income Taxes (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Income Taxes [Line Items] |  |  |
Interest income related to income taxes | $ 0 | $ 146 | $ 242
Public Service Company of New Mexico [Member] |  |  |
Income Taxes [Line Items] |  |  |
Interest income related to income taxes | 0 | 148 | 251
Texas-New Mexico Power Company [Member] |  |  |
Income Taxes [Line Items] |  |  |
Interest income related to income taxes | $ 0 | $ (2) | $ (2)

X
- Definition Income Taxes [Line Items] + References No definition available. + Details
Name: | pnm_IncomeTaxesLineItems
Namespace Prefix: | pnm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of interest expense for an underpayment of income taxes. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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: |