XML 69 R53.htm IDEA: XBRL DOCUMENT
v3.21.2

Stock-Based Compensation - Narrative (Details) - USD ($) $ in Millions | 6 Months Ended | 123 Months Ended
--- | --- | ---
Jun. 30, 2021 | Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Granted (in shares) |  | 0
Restricted Shares and Performance Based Shares |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Unrecognized expense related to stock awards | $ 6.4 |
Period of time stock expense is expected to be recognized | 1 year 9 months 18 days |
Executive | Performance Shares |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Maximum number of shares awarded in year one (in shares) | 142,080 |
Maximum number of shares awarded in year two (in shares) | 142,047 |
Maximum number of shares awarded in year three (in shares) | 152,414 |
Performance period | 3 years |
Executive | Performance Shares | Achieved performance target for 2017 through 2019 |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Maximum number of shares awarded in year one (in shares) | 124,941 |
Performance Equity Plan |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Vesting period | 3 years |
Vesting rate | 100.00% |
Performance Equity Plan | Non-employee Members of the Board of Directors |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Vesting period | 1 year |

X
- Definition Performance period + References No definition available. + Details
Name: | pnm_PerformancePeriod
Namespace Prefix: | pnm_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares in Year One + References No definition available. + Details
Name: | pnm_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesInYearOne
Namespace Prefix: | pnm_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares in Year Three + References No definition available. + Details
Name: | pnm_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesInYearThree
Namespace Prefix: | pnm_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares in Year Two + References No definition available. + Details
Name: | pnm_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesInYearTwo
Namespace Prefix: | pnm_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Vesting Rate + References No definition available. + Details
Name: | pnm_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingRate
Namespace Prefix: | pnm_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cost not yet recognized for nonvested award under share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Net number of share options (or share units) granted during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=pnm_RestrictedStockAndPerformanceSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_TitleOfIndividualAxis=srt_ManagementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | pnm_AchievedSpecifiedPerformanceTargetTimeFrameAxis=pnm_AchievedPerformanceTargetFor2017Through2019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=pnm_PerformanceEquityPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_TitleOfIndividualAxis=pnm_NonEmployeeMembersOfTheBoardOfDirectorsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |