XML 129 R95.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Asset Retirement Obligations (Details) (USD $) | 12 Months Ended
--- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] |  |  |  |  |
Liability Beginning Balance | $ 96,135,000us-gaap_AssetRetirementObligation |  | $ 85,893,000us-gaap_AssetRetirementObligation |  | $ 79,233,000us-gaap_AssetRetirementObligation
Liabilities incurred | 0us-gaap_AssetRetirementObligationLiabilitiesIncurred |  | 0us-gaap_AssetRetirementObligationLiabilitiesIncurred |  | 0us-gaap_AssetRetirementObligationLiabilitiesIncurred
Liabilities settled | 0us-gaap_AssetRetirementObligationLiabilitiesSettled |  | (79,000)us-gaap_AssetRetirementObligationLiabilitiesSettled |  | (25,000)us-gaap_AssetRetirementObligationLiabilitiesSettled
Accretion expense | 7,984,000us-gaap_AssetRetirementObligationAccretionExpense |  | 7,245,000us-gaap_AssetRetirementObligationAccretionExpense |  | 6,685,000us-gaap_AssetRetirementObligationAccretionExpense
Revisions to estimated cash flows | 51,000us-gaap_AssetRetirementObligationRevisionOfEstimate | [1] | 3,076,000us-gaap_AssetRetirementObligationRevisionOfEstimate | [1] |
Liability Ending Balance | 104,170,000us-gaap_AssetRetirementObligation |  | 96,135,000us-gaap_AssetRetirementObligation |  | 85,893,000us-gaap_AssetRetirementObligation
Public Service Company of New Mexico [Member] |  |  |  |  |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] |  |  |  |  |
Liability Beginning Balance | 95,225,000us-gaap_AssetRetirementObligation / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  | 85,042,000us-gaap_AssetRetirementObligation / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  | 78,425,000us-gaap_AssetRetirementObligation / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Liabilities incurred | 0us-gaap_AssetRetirementObligationLiabilitiesIncurred / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  | 0us-gaap_AssetRetirementObligationLiabilitiesIncurred / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  | 0us-gaap_AssetRetirementObligationLiabilitiesIncurred / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Liabilities settled | 0us-gaap_AssetRetirementObligationLiabilitiesSettled / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  | (67,000)us-gaap_AssetRetirementObligationLiabilitiesSettled / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  | 0us-gaap_AssetRetirementObligationLiabilitiesSettled / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Accretion expense | 7,906,000us-gaap_AssetRetirementObligationAccretionExpense / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  | 7,174,000us-gaap_AssetRetirementObligationAccretionExpense / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  | 6,617,000us-gaap_AssetRetirementObligationAccretionExpense / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Revisions to estimated cash flows | 51,000us-gaap_AssetRetirementObligationRevisionOfEstimate / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | [1] | 3,076,000us-gaap_AssetRetirementObligationRevisionOfEstimate / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember | [1] |
Liability Ending Balance | 103,182,000us-gaap_AssetRetirementObligation / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  | 95,225,000us-gaap_AssetRetirementObligation / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  | 85,042,000us-gaap_AssetRetirementObligation / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember
Public Service Company of New Mexico [Member] | Palo Verde Nuclear Generating Station [Member] |  |  |  |  |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] |  |  |  |  |
Asset Retirement Obligation, Period Increase (Decrease) | 500,000us-gaap_AssetRetirementObligationPeriodIncreaseDecrease / us-gaap_BusinessAcquisitionAxis = pnm_PaloVerdeNuclearGeneratingStationMember / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  |  |  |
Public Service Company of New Mexico [Member] | San Juan Generating Station [Member] |  |  |  |  |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] |  |  |  |  |
Asset Retirement Obligation, Period Increase (Decrease) | 2,500,000us-gaap_AssetRetirementObligationPeriodIncreaseDecrease / us-gaap_BusinessAcquisitionAxis = pnm_SanJuanGeneratingStationMember / dei_LegalEntityAxis = pnm_PublicServiceCompanyOfNewMexicoMember |  |  |  |
Texas-New Mexico Power Company [Member] |  |  |  |  |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] |  |  |  |  |
Liability Beginning Balance | 782,000us-gaap_AssetRetirementObligation / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  | 732,000us-gaap_AssetRetirementObligation / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  | 699,000us-gaap_AssetRetirementObligation / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Liabilities incurred | 0us-gaap_AssetRetirementObligationLiabilitiesIncurred / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  | 0us-gaap_AssetRetirementObligationLiabilitiesIncurred / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  | 0us-gaap_AssetRetirementObligationLiabilitiesIncurred / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Liabilities settled | 0us-gaap_AssetRetirementObligationLiabilitiesSettled / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  | (12,000)us-gaap_AssetRetirementObligationLiabilitiesSettled / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  | (25,000)us-gaap_AssetRetirementObligationLiabilitiesSettled / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Accretion expense | 66,000us-gaap_AssetRetirementObligationAccretionExpense / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  | 62,000us-gaap_AssetRetirementObligationAccretionExpense / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  | 58,000us-gaap_AssetRetirementObligationAccretionExpense / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
Revisions to estimated cash flows | 0us-gaap_AssetRetirementObligationRevisionOfEstimate / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | [1] | 0us-gaap_AssetRetirementObligationRevisionOfEstimate / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember | [1] |
Liability Ending Balance | $ 848,000us-gaap_AssetRetirementObligation / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  | $ 782,000us-gaap_AssetRetirementObligation / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember |  | $ 732,000us-gaap_AssetRetirementObligation / dei_LegalEntityAxis = pnm_TexasNewMexicoPowerCompanyMember
[1] | Based on studies to estimate the amount and timing of future ARO expenditures. PNM has an ARO for PVNGS that includes the obligations for nuclear decommissioning of that facility. In 2013, a new decommissioning study for PVNGS was implemented reflecting updated cash flow estimates, including the extended operating licenses. The new study resulted in an increase of $0.5 million to the ARO. In addition, a new decommissioning study for SJGS was implemented in 2013, resulting in a $2.5 million increase to the ARO.

X
- Definition The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Asset Retirement Obligation -URI http://asc.fasb.org/extlink&oid=6505190 + Details
Name: | us-gaap_AssetRetirementObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_AssetRetirementObligationAccretionExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of asset retirement obligations incurred during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_AssetRetirementObligationLiabilitiesIncurred
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_AssetRetirementObligationLiabilitiesSettled
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Net Increase or Decrease in the asset retirement obligation during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_AssetRetirementObligationPeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of the Increase or Decrease in the amount of the asset retirement obligation during the current period for changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c)(4) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_AssetRetirementObligationRevisionOfEstimate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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