XML 151 R126.htm IDEA: XBRL DOCUMENT v3.10.0.1

Income Taxes - Interest Income (Expense) Related to Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Interest income related to income taxes	$ 0	$ 0	$ 4,398
Public Service Company of New Mexico
Income Taxes [Line Items]
Interest income related to income taxes	0	0	3,625
Texas-New Mexico Power Company
Income Taxes [Line Items]
Interest income related to income taxes	0	$ 0	345
Interest income and interest expense applicable to federal income tax matters
Income Taxes [Line Items]
Net refunds received			6,500
Increase (decrease) of net interest receivable			2,100
Interest income			5,100
Interest expense			700
Professional fees			900
Net pre-tax impacts			3,500
Interest income and interest expense applicable to federal income tax matters | Public Service Company of New Mexico
Income Taxes [Line Items]
Net pre-tax impacts			2,600
Interest income and interest expense applicable to federal income tax matters | Texas-New Mexico Power Company
Income Taxes [Line Items]
Net pre-tax impacts			300
Interest income and interest expense applicable to federal income tax matters | Corporate and Other
Income Taxes [Line Items]
Net pre-tax impacts			$ 600
2015 Electric Rate Case | Public Service Company of New Mexico
Income Taxes [Line Items]
Approval to recover impairment of net operating loss carryforward	$ (2,100)

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

Net settlement with taxing authority, pre-tax

+ References

No definition available.

+ Details

Name:	pnm_Netsettlementwithtaxingauthoritypretax
Namespace Prefix:	pnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Net settlement with taxing authority, pre-tax, segment allocation

+ References

No definition available.

+ Details

Name:	pnm_Netsettlementwithtaxingauthoritypretaxsegmentallocation
Namespace Prefix:	pnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The increase (decrease) during the reporting period in the aggregate amount due to the entity in the form of unpaid interest and dividends.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

+ Details

Name:	us-gaap_IncreaseDecreaseInInterestAndDividendsReceivable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount of interest expense classified as other.

+ References

No definition available.

+ Details

Name:	us-gaap_InterestExpenseOther
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of interest income earned from interest bearing assets classified as other.

+ References

No definition available.

+ Details

Name:	us-gaap_InterestIncomeOther
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The amount of cash received during the period as refunds for the overpayment of taxes.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3536-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4297-108586

+ Details

Name:	us-gaap_ProceedsFromIncomeTaxRefunds
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

A fee charged for services from professionals such as doctors, lawyers and accountants. The term is often expanded to include other professions, for example, pharmacists charging to maintain a medicinal profile of a client or customer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07.2(a),(b),(c),(d))
-URI http://asc.fasb.org/extlink&oid=114873854&loc=SL114874292-224272

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 220
-Section 45
-Paragraph 3
-Subparagraph (k)
-URI http://asc.fasb.org/extlink&oid=114873831&loc=SL114874205-224268

+ Details

Name:	us-gaap_ProfessionalFees
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 25
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=115928272&loc=d3e28511-109314

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 25
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=115928272&loc=d3e28446-109314

+ Details

Name:	us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of interest expense for an underpayment of income taxes.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84230637&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:

X

- Details

Name:	pnm_TaxingauthorityexaminationsIRSAxis=pnm_InterestIncomeandInterestExpenseapplicabletofederalincometaxmattersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=pnm_PublicServiceCompanyOfNewMexicoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=pnm_TexasNewMexicoPowerCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=us-gaap_CorporateAndOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	pnm_ScheduleOfRegulatoryRateMattersAxis=pnm_A2015ElectricRateCaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: