Cover Page - shares	3 Months Ended
	Mar. 31, 2022	Apr. 21, 2022
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Document Transition Report	false
Entity Registrant Name	PNM Resources, Inc.
Entity Incorporation, State or Country Code	NM
Entity Address, Address Line One	414 Silver Ave. SW
Entity Address, City or Town	Albuquerque
Entity Address, State or Province	NM
Entity Address, Postal Zip Code	87102-3289
City Area Code	505
Local Phone Number	241-2700
Entity File Number	001-32462
Entity Tax Identification Number	85-0468296
Title of 12(b) Security	Common Stock, no par value
Trading Symbol	PNM
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		85,834,874
Entity Central Index Key	0001108426
Document Fiscal Year Focus	2022
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Amendment Flag	false
PNM
Entity Information [Line Items]
Entity Registrant Name	Public Service Company of New Mexico
Entity Address, Address Line One	414 Silver Ave. SW
Entity Address, City or Town	Albuquerque
Entity Address, State or Province	NM
Entity Address, Postal Zip Code	87102-3289
City Area Code	505
Local Phone Number	241-2700
Entity File Number	001-06986
Entity Tax Identification Number	85-0019030
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		39,117,799
Entity Central Index Key	0000081023
Current Fiscal Year End Date	--12-31
Texas-New Mexico Power Company
Entity Information [Line Items]
Entity Registrant Name	Texas-New Mexico Power Company
Entity Address, Address Line One	577 N. Garden Ridge Blvd.
Entity Address, City or Town	Lewisville
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75067
City Area Code	972
Local Phone Number	420-4189
Entity File Number	002-97230
Entity Tax Identification Number	75-0204070
Entity Current Reporting Status	No
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		6,358
Entity Central Index Key	0000022767
Current Fiscal Year End Date	--12-31