Consolidated Statements of Changes in Equity - TNMP - USD ($) $ in Thousands	Total	Retained Earnings	Texas-New Mexico Power Company	Texas-New Mexico Power Company Common Stock	Texas-New Mexico Power Company Paid-in Capital	Texas-New Mexico Power Company Retained Earnings
Beginning Balance at Dec. 31, 2018			$ 674,093	$ 64	$ 534,166	$ 139,863
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings			55,799			55,799
Equity contribution from parent			80,000		80,000
Dividends declared on common stock	$ (93,792)	$ (93,792)	(55,265)			(55,265)
Ending Balance at Dec. 31, 2019			754,627	64	614,166	140,397
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings			58,585			58,585
Equity contribution from parent			71,000		71,000
Dividends declared on common stock	(101,591)	(101,591)	(58,534)			(58,534)
Ending Balance at Dec. 31, 2020	2,049,465		825,678	64	685,166	140,448
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings			63,879			63,879
Equity contribution from parent			52,000		52,000
Dividends declared on common stock	(84,333)	$ (84,333)
Ending Balance at Dec. 31, 2021	$ 2,167,524		$ 941,557	$ 64	$ 737,166	$ 204,327