Long-term debt, Current maturities, Gross

No definition available.

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

- Definition

Long-term debt, Excluding current maturities, Gross

+ References

No definition available.

+ Details

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

- Definition

Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums, Current Portion

+ References

No definition available.

+ Details

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

- Definition

Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums, Excluding Current Portion

+ References

No definition available.

+ Details

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

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=123466204&loc=SL6031897-161870

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69C
-URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69B
-URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6378536&loc=d3e10092-111533

+ Details

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

- Definition

Carrying value as of the balance sheet date of uncollateralized debt obligation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

Financing - Long-term Debt (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Dec. 22, 2020	Dec. 21, 2020
Debt Instrument [Line Items]
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 124,000	$ (1,107,000)
Total	3,699,043,000	3,294,043,000
Principal, less current maturities	179,500,000	576,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net, Less current maturities	161,000	482,000
Long-term debt, excluding current maturities, gross	3,519,543,000	2,718,043,000
Unamortized Discounts, (Premiums), and Issuance Costs, net, excluding current maturities	(37,000)	$ (1,589,000)
PNMR 2020 Delayed-Draw Term Loan
Debt Instrument [Line Items]
Term loans			$ 300,000,000
PNMR 2020 Term Loan
Debt Instrument [Line Items]
Term loans				$ 150,000,000
Senior Unsecured Notes: \| PNMR 3.25% 2018 SUNs due March 2021
Debt Instrument [Line Items]
Stated percentage		3.25%
Public Service Company of New Mexico
Debt Instrument [Line Items]
Unamortized Discounts, (Premiums), and Issuance Costs, net	9,735,000	$ 9,225,000
Total	1,890,845,000	1,705,845,000
Principal, less current maturities	179,500,000	346,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net, Less current maturities	161,000	430,000
Long-term debt, excluding current maturities, gross	1,711,345,000	1,359,845,000
Unamortized Discounts, (Premiums), and Issuance Costs, net, excluding current maturities	9,574,000	8,795,000
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| 1.875% due April 2033, mandatory tender - October 1, 2021
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	0	146,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 0	301,000
Stated percentage	1.875%
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| 2.15% due April 2033
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 146,000,000	0
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 1,003,000	0
Stated percentage	2.15%
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| 2.125% due June 2040, mandatory tender - June 1, 2022
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 37,000,000	37,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 45,000	135,000
Stated percentage	2.125%
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| 2.45% due September 2042, mandatory tender - June 1, 2022
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 20,000,000	20,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 17,000	50,000
Stated percentage	2.45%
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| Floating rate, weekly-mode
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 0	100,345,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	0	798,000
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| 0.875% due October 2026
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	100,345,000	0
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 697,000	0
Stated percentage	0.875%
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| 1.05% due January 2038, mandatory tender - June 1, 2022
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 36,000,000	36,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 75,000	226,000
Stated percentage	1.05%
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| 1.20% due June 2040, mandatory tender - June 1, 2022
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 11,500,000	11,500,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 24,000	72,000
Stated percentage	1.20%
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| 1.10% due June 2040, mandatory tender June 1, 2023
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 130,000,000	130,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 535,000	892,000
Stated percentage	1.10%
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| 1.15% due June 2040, mandatory tender - June 1, 2024
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 125,000,000	125,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 639,000	894,000
Stated percentage	1.15%
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| 2.59% due July 2033
Debt Instrument [Line Items]
Stated percentage	2.59%
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| 3.14% due July 2041
Debt Instrument [Line Items]
Stated percentage	3.14%
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| 2.29% due December 2031
Debt Instrument [Line Items]
Stated percentage	2.29%
Public Service Company of New Mexico \| Senior Unsecured Notes, Pollution Control Revenue Bonds: \| 2.97% due December 2041
Debt Instrument [Line Items]
Stated percentage	2.97%
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 5.35% due October 2021
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 0	160,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 0	129,000
Stated percentage	5.35%
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 3.15% due May 2023
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 55,000,000	55,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 106,000	184,000
Stated percentage	3.15%
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 3.45% due May 2025
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 104,000,000	104,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 353,000	457,000
Stated percentage	3.45%
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 3.85% due August 2025
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 250,000,000	250,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 1,075,000	1,375,000
Stated percentage	3.85%
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 3.68% due May 2028
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 88,000,000	88,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 395,000	457,000
Stated percentage	3.68%
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 3.78% due August 2028
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 15,000,000	15,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 69,000	80,000
Stated percentage	3.78%
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 3.93% due May 2033
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 38,000,000	38,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 203,000	221,000
Stated percentage	3.93%
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 4.22% due May 2038
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 45,000,000	45,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 259,000	275,000
Stated percentage	4.22%
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 4.50% due May 2048
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 20,000,000	20,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 124,000	128,000
Stated percentage	4.50%
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 4.60% due August 2048
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 85,000,000	85,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 530,000	550,000
Stated percentage	4.60%
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 3.21% due April 2030
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 150,000,000	150,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 1,331,000	1,490,000
Stated percentage	3.21%
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 3.57% due April 2039
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 50,000,000	50,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 482,000	511,000
Stated percentage	3.57%
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 2.59% due July 2033
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 80,000,000	0
Unamortized Discounts, (Premiums), and Issuance Costs, net	443,000	0
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 3.14% due July 2041
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	80,000,000	0
Unamortized Discounts, (Premiums), and Issuance Costs, net	450,000	0
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 2.29% due December 2031
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	50,000,000	0
Unamortized Discounts, (Premiums), and Issuance Costs, net	293,000	0
Public Service Company of New Mexico \| Senior Unsecured Notes: \| 2.97% due December 2041
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	100,000,000	0
Unamortized Discounts, (Premiums), and Issuance Costs, net	587,000	0
Public Service Company of New Mexico \| Senior Unsecured Notes: \| PNM 2019 $40.0 Million Term Loan due June 2021
Debt Instrument [Line Items]
Term loans	0	40,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	0	0
Public Service Company of New Mexico \| Senior Unsecured Notes: \| PNM 2021 $75.0 Million Term Loan due December 2022
Debt Instrument [Line Items]
Term loans	75,000,000	0
Unamortized Discounts, (Premiums), and Issuance Costs, net	0	0
Texas-New Mexico Power Company
Debt Instrument [Line Items]
Unamortized Discounts, (Premiums), and Issuance Costs, net	(9,852,000)	(10,475,000)
Total	908,198,000	843,198,000
Principal, less current maturities	0	0
Unamortized Discounts, (Premiums), and Issuance Costs, net, Less current maturities	0	0
Long-term debt, excluding current maturities, gross	908,198,000	843,198,000
Unamortized Discounts, (Premiums), and Issuance Costs, net, excluding current maturities	(9,852,000)	(10,475,000)
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 6.95% due April 2043
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	93,198,000	93,198,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ (15,202,000)	(15,917,000)
Stated percentage	6.95%
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 4.03% due July 2024
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 80,000,000	80,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 264,000	369,000
Stated percentage	4.03%
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 3.53% due February 2026
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 60,000,000	60,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 338,000	420,000
Stated percentage	3.53%
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 3.22% due August 2027
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 60,000,000	60,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 324,000	380,000
Stated percentage	3.22%
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 3.85% due June 2028
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 60,000,000	60,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 406,000	469,000
Stated percentage	3.85%
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 3.79% due March 2034
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 75,000,000	75,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 460,000	497,000
Stated percentage	3.79%
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 3.92% due March 2039
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 75,000,000	75,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 486,000	514,000
Stated percentage	3.92%
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 4.06% due March 2044
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 75,000,000	75,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 501,000	524,000
Stated percentage	4.06%
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 3.60% due July 2029
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 80,000,000	80,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 451,000	511,000
Stated percentage	3.60%
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 2.73% due April 2030
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 85,000,000	85,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 699,000	784,000
Stated percentage	2.73%
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 3.36% due April 2050
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 25,000,000	25,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 235,000	243,000
Stated percentage	3.36%
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 2.93% due July 2035
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 25,000,000	25,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 224,000	241,000
Stated percentage	2.93%
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 3.36% due July 2050
Debt Instrument [Line Items]
Unsecured long-term debt, noncurrent	$ 50,000,000	50,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 473,000	490,000
Stated percentage	3.36%
Texas-New Mexico Power Company \| First Mortgage Bonds: \| 2.44% due August 2035
Debt Instrument [Line Items]
Term loans	$ 65,000,000	0
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 489,000	0
Stated percentage	2.44%
PNMR
Debt Instrument [Line Items]
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 241,000	143,000
Total	900,000,000	745,000,000
Principal, less current maturities	0	230,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net, Less current maturities	0	52,000
Long-term debt, excluding current maturities, gross	900,000,000	515,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net, excluding current maturities	241,000	91,000
PNMR \| PNMR 2020 Delayed-Draw Term Loan
Debt Instrument [Line Items]
Term loans	0	80,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	0	0
PNMR \| PNMR 2021 Delayed-Draw Term Loan due May 2023
Debt Instrument [Line Items]
Term loans	900,000,000	0
Unamortized Discounts, (Premiums), and Issuance Costs, net	241,000	0
PNMR \| PNMR 3.25% 2018 SUNs due March 2021
Debt Instrument [Line Items]
Term loans	0	300,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 0	137,000
Stated percentage	3.25%
PNMR \| PNMR Development Term Loan due January 2022
Debt Instrument [Line Items]
Term loans	$ 0	65,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	0	0
PNMR \| PNMR 2019 Term Loan due June 2021
Debt Instrument [Line Items]
Term loans	0	150,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	0	6,000
PNMR \| PNMR 2020 Term Loan
Debt Instrument [Line Items]
Term loans	0	150,000,000
Unamortized Discounts, (Premiums), and Issuance Costs, net	$ 0	$ 0