Condensed Consolidated Statements of Cash Flows - PNM - 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
(Gains) losses on investment securities	84,104	(16,108)
Regulatory disallowances and restructuring costs	832	436
Allowance for equity funds used during construction	(9,232)	(8,867)
Other, net	1,323	4,594
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)
Proceeds from sales of investment securities	323,251	396,870
Purchases of investment securities	(332,490)	(405,142)
Other, net	692	108
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
Repayment of long-term debt	(179,500)	(1,165,000)
Dividends paid	(89,879)	(84,729)
Valencia’s transactions with its owner	(12,455)	(14,238)
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 (refunded), net	904	892
Supplemental schedule of noncash investing activities:
Decrease in accrued plant additions	56,948	63,281
PNM
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Earnings	106,855	158,842
Adjustments to reconcile net earnings to net cash flows from operating activities:
Depreciation and amortization	161,303	151,775
Deferred income tax expense	11,762	24,034
(Gains) losses on investment securities	84,104	(16,108)
Regulatory disallowances and restructuring costs	832	436
Allowance for equity funds used during construction	(6,793)	(6,655)
Other, net	2,839	3,488
Changes in certain assets and liabilities:
Accounts receivable and unbilled revenues	(45,252)	(34,110)
Materials, supplies, and fuel stock	(3,809)	143
Other current assets	885	(20,398)
Other assets	7,958	14,541
Accounts payable	20,308	14,411
Accrued interest and taxes	14,799	13,370
Other current liabilities	(35,503)	12,442
Other liabilities	(24,717)	(34,394)
Net cash flows from operating activities	295,571	281,817
Cash Flows From Investing Activities:
Utility plant additions	(322,412)	(247,064)
Proceeds from sales of investment securities	323,251	396,870
Purchases of investment securities	(332,490)	(405,142)
Other, net	492	108
Net cash flows used in investing activities	(331,159)	(255,228)
Cash Flows From Financing Activities:
Revolving credit facilities borrowings (repayments), net	(7,400)	(10,000)
Long-term borrowings	298,000	235,000
Repayment of long-term debt	(179,500)	(200,000)
Dividends paid	(85,396)	(60,396)
Valencia’s transactions with its owner	(12,455)	(14,238)
Transmission interconnection and security deposit arrangements	70,296	28,278
Refunds paid under transmission interconnection arrangements	(41,401)	(2,450)
Debt issuance costs and other, net	(2,201)	(1,665)
Net cash flows from financing activities	39,943	(25,471)
Change in Cash, Restricted Cash, and Equivalents	4,355	1,118
Cash, Restricted Cash, and Equivalents at Beginning of Period	19	31,446
Cash, Restricted Cash, and Equivalents at End of Period	4,374	32,564
Supplemental Cash Flow Disclosures:
Interest paid, net of amounts capitalized	37,269	33,189
Income taxes paid (refunded), net	0	0
Supplemental schedule of noncash investing activities:
Decrease in accrued plant additions	$ 21,069	$ 45,441