Preferred stock, redemption premium percent.

No definition available.

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- Definition

Ratio of debt to capital, maximum

+ References

No definition available.

+ Details

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- Definition

This element represents disclosure of the aggregate cash dividends paid to the entity by consolidated subsidiaries.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 235

-Section S99

-Paragraph 2

-Subparagraph (SX 210.9-06)

-URI http://asc.fasb.org/extlink&oid=6882215&loc=d3e537971-122884

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 06

-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph b

-Article 12

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 3

-Subparagraph (SX 210.12-04.(b))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690

+ Details

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Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_ClassOfStockLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage rate used to calculate dividend payments on preferred stock.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.28)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29

-Article 5

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

+ References

+ Details

Name:	us-gaap_PreferredStockSharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow from parent as a source of financing that is recorded as additional paid in capital.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

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

- Definition

Amount of dividends that can be declared or paid without approval of regulatory agency.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(e))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph e

-Article 4

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	dei_LegalEntityAxis=pnm_PNMRandTNMPMember
Namespace Prefix:
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- Details

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- Details

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- Details

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- Details

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Stockholders' Equity (Details) (USD $)	12 Months Ended
Stockholders' Equity (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Class of Stock [Line Items]
Preferred stock, cumulative shares authorized (in shares)	10,000,000us-gaap_PreferredStockSharesAuthorized
Texas-New Mexico Power Company [Member]
Class of Stock [Line Items]
Equity contribution from parent		$ 13,800,000
Amount available for dividend distribution without prior approval from regulators or financial counterparties	203,000,000
Preferred stock, cumulative shares authorized (in shares)	1,000,000
Public Service Company of New Mexico [Member]
Class of Stock [Line Items]
Amount available for dividend distribution without prior approval from regulators or financial counterparties	223,000,000
Preferred stock, dividend rate (as a percent)	4.58%
Preferred stock, redemption percent (as a percent)	102.00%
Preferred Stock, Shares Outstanding	115,293	115,293
Preferred stock, cumulative shares authorized (in shares)	10,000,000	10,000,000
PNMR and TNMP [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	0
Affiliated Entity [Member] \| Texas-New Mexico Power Company [Member]
Class of Stock [Line Items]
Cash dividends paid to parent company by consolidated subsidiaries	16,300,000	3,700,000	26,000,000
Affiliated Entity [Member] \| Public Service Company of New Mexico [Member]
Class of Stock [Line Items]
Cash dividends paid to parent company by consolidated subsidiaries	$ 30,300,000	$ 155,000,000	$ 34,400,000
Line of Credit [Member] \| Texas-New Mexico Power Company [Member]
Class of Stock [Line Items]
Ratio of debt to capital, maximum (as a percent)	65.00%