Regulatory and Rate Matters - FERC Compliance (Details) $ in Millions						3 Months Ended
	Nov. 21, 2022 USD ($)	Jul. 29, 2022 filedPetition	Jul. 18, 2022 denialNotice	Jun. 16, 2022 USD ($) numberOfAMIMeter proceeding	May 17, 2022 delegatedLetterOrder	Dec. 31, 2022 USD ($)
Public Utilities, General Disclosures [Line Items]
Number of delegated letter orders \| delegatedLetterOrder					2
Number of requests for rehearing \| numberOfAMIMeter				2
Number of FERC proceedings \| proceeding				2
Number of rehearing denial notices \| denialNotice			2
Number of petitions filed for review \| filedPetition		2
Public Service Company of New Mexico
Public Utilities, General Disclosures [Line Items]
Compliance extension period				75 days
Compliance extension period, repost period				30 days
Time-value refunds	$ 8.1
Payment of time-value refunds						$ 8.1
Public Service Company of New Mexico \| FERC Proceedings One
Public Utilities, General Disclosures [Line Items]
Time-value customer refund				$ 7.0
Public Service Company of New Mexico \| FERC Proceedings Two
Public Utilities, General Disclosures [Line Items]
Time-value customer refund				$ 28.0