XML 65 R38.htm IDEA: XBRL DOCUMENT v3.4.0.3

Lease Commitments (Details) - Public Service Company of New Mexico [Member] $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($) MW	Mar. 31, 2015	Apr. 01, 2015 USD ($)
Operating Leased Assets [Line Items]
Ownership of the EIP		60.00%
Percent leased, now expired			40.00%
Leased capacity at fair market value, elected to purchase			$ 7.7
Palo Verde Nuclear Generating Station, Unit 2 Leases 31.2494 MW [Member]
Operating Leased Assets [Line Items]
Payment to lessors	$ 78.1
Palo Verde Nuclear Generating Station, Unit 2 Leases [Member]
Operating Leased Assets [Line Items]
Leased capacity to be purchased (in megawatts) | MW	32.76
Palo Verde Nuclear Generating Station, Unit 2 Leases, January 15, 2016 [Member]
Operating Leased Assets [Line Items]
Leased capacity to be purchased (in megawatts) | MW	31.25
Palo Verde Nuclear Generating Station, Unit 2 Leases 32.76 MW [Member]
Operating Leased Assets [Line Items]
Payment to lessors	$ 85.2
Palo Verde Nuclear Generating Station [Member]
Operating Leased Assets [Line Items]
Loss contingency, lease arrangements	$ 179.1

X

- Definition

Leased Capacity to be Purchased

+ References

No definition available.

+ Details

Name:	pnm_LeasedCapacitytobePurchased
Namespace Prefix:	pnm_
Data Type:	num:powerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Public Utilities, Additional ownership percentage in EIP purchased

+ References

No definition available.

+ Details

Name:	pnm_PublicUtilitiesAdditionalownershippercentageinEIPpurchased
Namespace Prefix:	pnm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Public Utilities, Lease ownership percentage in EIP

+ References

No definition available.

+ Details

Name:	pnm_PublicUtilitiesLeaseOwnershipPercentageInEip
Namespace Prefix:	pnm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Public Utilities, Option to Purchase Leased Capacity At Fair Value

+ References

No definition available.

+ Details

Name:	pnm_PublicUtilitiesOptionToPurchaseLeasedCapacityAtFairValue
Namespace Prefix:	pnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Purchase Price of Leased Asset, Paid

+ References

No definition available.

+ Details

Name:	pnm_PurchasePriceofLeasedAssetPaid
Namespace Prefix:	pnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The difference between the maximum amount of estimated loss and the amount recorded as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 05
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6395354&loc=d3e12631-108344

+ Details

Name:	us-gaap_LossContingencyRangeOfPossibleLossPortionNotAccrued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_OperatingLeasedAssetsLineItems
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:	us-gaap_LeaseArrangementTypeAxis=pnm_PaloVerdeNuclearGeneratingStationUnit2Leases31.2494MWMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=pnm_PaloVerdeNuclearGeneratingStationUnit2LeasesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=pnm_PaloVerdeNuclearGeneratingStationUnit2LeasesJanuary152016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=pnm_PaloVerdeNuclearGeneratingStationUnit2Leases32.76MWMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=pnm_PaloVerdeNuclearGeneratingStationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: