Condensed Consolidated Statements of Cash Flows - TNMP - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Earnings	$ 165,078	$ 196,648
Adjustments to reconcile net earnings to net cash flows from operating activities:
Depreciation and amortization	255,808	238,963
Deferred income tax expense	15,036	25,293
Allowance for equity funds used during construction	(9,232)	(8,867)
Changes in certain assets and liabilities:
Accounts receivable and unbilled revenues	(66,713)	(46,649)
Materials, supplies, and fuel stock	(6,630)	(333)
Other current assets	3,687	(20,005)
Other assets	6,676	17,551
Accounts payable	11,845	5,934
Accrued interest and taxes	17,875	7,713
Other current liabilities	(26,082)	17,679
Other liabilities	(32,083)	(21,065)
Net cash flows from operating activities	427,496	408,512
Cash Flows From Investing Activities:
Utility plant additions	(702,878)	(496,185)
Net cash flows used in investing activities	(711,425)	(503,777)
Cash Flows From Financing Activities:
Revolving credit facilities borrowings (repayments), net	(2,500)	(18,100)
Long-term borrowings	558,000	1,370,000
Transmission interconnection and security deposit arrangements	76,696	31,878
Refunds paid under transmission interconnection arrangements	(50,401)	(9,752)
Debt issuance costs and other, net	(3,668)	(3,159)
Net cash flows from financing activities	288,447	96,818
Change in Cash, Restricted Cash, and Equivalents	4,518	1,553
Cash, Restricted Cash, and Equivalents at Beginning of Period	1,104	47,928
Cash, Restricted Cash, and Equivalents at End of Period	5,622	49,481
Supplemental Cash Flow Disclosures:
Interest paid, net of amounts capitalized	79,246	69,965
Income taxes paid, net	904	892
Supplemental schedule of noncash investing activities:
Decrease in accrued plant additions	56,948	63,281
Texas-New Mexico Power Company
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Earnings	72,542	52,326
Adjustments to reconcile net earnings to net cash flows from operating activities:
Depreciation and amortization	73,536	68,378
Deferred income tax expense	(3,587)	(6,377)
Allowance for equity funds used during construction	(2,441)	(2,152)
Changes in certain assets and liabilities:
Accounts receivable and unbilled revenues	(21,461)	(12,539)
Materials, supplies, and fuel stock	(2,821)	(476)
Other current assets	2,696	(4,927)
Other assets	(387)	5,168
Accounts payable	(3,791)	(4,050)
Accrued interest and taxes	14,449	10,800
Other current liabilities	7,769	(754)
Other liabilities	(4,324)	11,538
Net cash flows from operating activities	132,180	116,935
Cash Flows From Investing Activities:
Utility plant additions	(359,441)	(233,381)
Net cash flows used in investing activities	(359,441)	(233,381)
Cash Flows From Financing Activities:
Revolving credit facilities borrowings (repayments), net	2,600	0
Long-term borrowings	160,000	65,000
Equity contribution from parent	68,000	52,000
Transmission interconnection and security deposit arrangements	6,400	3,600
Refunds paid under transmission interconnection arrangements	(9,000)	(7,302)
Debt issuance costs and other, net	(739)	(736)
Net cash flows from financing activities	227,261	112,562
Change in Cash, Restricted Cash, and Equivalents	0	(3,884)
Cash, Restricted Cash, and Equivalents at Beginning of Period	0	14,800
Cash, Restricted Cash, and Equivalents at End of Period	0	10,916
Supplemental Cash Flow Disclosures:
Interest paid, net of amounts capitalized	26,810	25,085
Income taxes paid, net	904	892
Supplemental schedule of noncash investing activities:
Decrease in accrued plant additions	$ 24,773	$ 14,166