XML 136 R106.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2

Commitments and Contingencies - Mining Royalty Rate (Details) - Continuous Highwall Mining - San Juan Generating Station - USD ($) $ in Millions	Dec. 31, 2019	Aug. 31, 2013
Public Utilities, General Disclosures [Line Items]
Proposed retroactive surface mining royalty rate		12.50%
Surface mining royalty rate applied between 2000 and 2003	8.00%
Estimated underpaid surface mining royalties under proposed rate change	$ 5
PNM's share of estimated underpaid surface mining royalties under proposed rate change	46.30%

X

- Definition

Public Utilities, Current Surface Mining Royalty Rate applied between 2000 and 2003

+ References

No definition available.

+ Details

Name:	pnm_PublicUtilitiesCurrentSurfaceMiningRoyaltyRateappliedbetween2000and2003
Namespace Prefix:	pnm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Public Utilities, Estimated Underpaid Surface Mining Royalties under proposed rate change

+ References

No definition available.

+ Details

Name:	pnm_PublicUtilitiesEstimatedUnderpaidSurfaceMiningRoyaltiesunderproposedratechange
Namespace Prefix:	pnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Public Utilities, PNM Share Estimated Underpaid Surface Mining Royalties under proposed rate change

+ References

No definition available.

+ Details

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

X

- Definition

Public Utilities, Proposed Retroactive Surface Mining Royalty Rate

+ References

No definition available.

+ Details

Name:	pnm_PublicUtilitiesProposedRetroactiveSurfaceMiningRoyaltyRate
Namespace Prefix:	pnm_
Data Type:	num:percentItemType
Balance Type:	na
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_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_OtherCommitmentsAxis=pnm_ContinuousHighwallMiningMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	pnm_JointlyOwnedGeneratingFacilitiesAxis=pnm_SanJuanGeneratingStationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: