Condensed Consolidated Statements of Cash Flows - PNM - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net earnings	$ 19,218	$ 21,205
Adjustments to reconcile net earnings to net cash flows from operating activities:
Depreciation and amortization	84,672	78,857
Deferred income tax expense	2,009	1,447
(Gains) losses on investment securities	26,486	(967)
Allowance for equity funds used during construction	(2,668)	(2,621)
Other, net	708	3,234
Changes in certain assets and liabilities:
Accounts receivable and unbilled revenues	21,169	17,205
Materials, supplies, and fuel stock	(5,183)	4,305
Other current assets	13,079	(18,978)
Other assets	(12,215)	6,561
Accounts payable	(15,905)	(9,647)
Accrued interest and taxes	909	76
Other current liabilities	(6,458)	(4,369)
Other liabilities	(12,263)	(14,050)
Net cash flows from operating activities	116,610	86,477
Cash Flows From Investing Activities:
Utility plant additions	(209,884)	(172,235)
Proceeds from sales of investment securities	125,246	123,596
Purchases of investment securities	(127,791)	(126,485)
Other, net	565	97
Net cash flows used in investing activities	(211,864)	(174,455)
Cash Flows From Financing Activities:
Revolving credit facilities borrowings (repayments), net	23,300	165,500
Dividends paid	(29,960)	(28,243)
Valencia’s transactions with its owner	(4,232)	(5,243)
Transmission interconnection and security deposit arrangements	18,569	5,460
Refunds paid under transmission interconnection arrangements	(1,972)	(584)
Debt issuance costs and other, net	(431)	(292)
Net cash flows from financing activities	98,539	47,571
Change in Cash, Restricted Cash, and Equivalents	3,285	(40,407)
Cash, Restricted Cash, and Equivalents at Beginning of Period	1,104	47,928
Cash, Restricted Cash, and Equivalents at End of Period	4,389	7,521
Supplemental Cash Flow Disclosures:
Interest paid, net of amounts capitalized	21,682	23,317
Income taxes paid (refunded), net	(346)	0
Supplemental schedule of noncash investing activities:
Decrease in accrued plant additions	38,918	49,092
PNM
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net earnings	7,538	22,162
Adjustments to reconcile net earnings to net cash flows from operating activities:
Depreciation and amortization	53,844	50,108
Deferred income tax expense	893	2,910
(Gains) losses on investment securities	26,486	(967)
Allowance for equity funds used during construction	(2,294)	(2,135)
Other, net	894	911
Changes in certain assets and liabilities:
Accounts receivable and unbilled revenues	22,466	17,491
Materials, supplies, and fuel stock	(4,636)	4,341
Other current assets	11,418	(21,763)
Other assets	(11,065)	5,780
Accounts payable	(6,876)	(934)
Accrued interest and taxes	14,873	14,729
Other current liabilities	(4,879)	(1,911)
Other liabilities	(10,198)	(13,196)
Net cash flows from operating activities	98,464	77,526
Cash Flows From Investing Activities:
Utility plant additions	(96,359)	(88,198)
Proceeds from sales of investment securities	125,246	123,596
Purchases of investment securities	(127,791)	(126,485)
Other, net	565	97
Net cash flows used in investing activities	(98,339)	(90,990)
Cash Flows From Financing Activities:
Revolving credit facilities borrowings (repayments), net	(2,700)	(10,000)
Dividends paid	(132)	(132)
Valencia’s transactions with its owner	(4,232)	(5,243)
Transmission interconnection and security deposit arrangements	12,170	3,810
Refunds paid under transmission interconnection arrangements	(1,972)	(584)
Debt issuance costs and other, net	(293)	87
Net cash flows from financing activities	2,841	(12,062)
Change in Cash, Restricted Cash, and Equivalents	2,966	(25,526)
Cash, Restricted Cash, and Equivalents at Beginning of Period	19	31,446
Cash, Restricted Cash, and Equivalents at End of Period	2,985	5,920
Supplemental Cash Flow Disclosures:
Interest paid, net of amounts capitalized	9,070	7,568
Income taxes paid (refunded), net	0	0
Supplemental schedule of noncash investing activities:
Decrease in accrued plant additions	$ 26,620	$ 30,828