Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018
Current Assets:
Cash and cash equivalents	$ 30,893	$ 3,833	$ 20,094	$ 2,122
Accounts receivable, net of allowance for credit losses	135,400	85,889
Unbilled revenues	64,321	57,416
Other receivables	12,972	12,165
Materials, supplies, and fuel stock	67,435	77,929
Regulatory assets	11,913	7,373
Income taxes receivable	4,981	4,933
Other current assets	50,070	44,472
Total current assets	377,985	294,010
Other Property and Investments:
Investment securities	408,551	388,832
Equity investment in NMRD	90,519	65,159
Other investments	189	356
Non-utility property, net	22,086	12,459
Total other property and investments	521,345	466,806
Utility Plant:
Plant in service, held for future use, and to be abandoned	8,106,592	7,918,601
Less accumulated depreciation and amortization	2,811,168	2,713,503
Net plant in service and plant held for future use	5,295,424	5,205,098
Construction work in progress	379,848	161,106
Nuclear fuel, net of accumulated amortization	99,115	99,805
Net utility plant	5,774,387	5,466,009
Deferred Charges and Other Assets:
Regulatory assets	571,833	556,930
Goodwill	278,297	278,297	278,297
Operating lease right-of-use assets, net of accumulated amortization	111,638	131,212
Other deferred charges	106,627	105,510
Total deferred charges and other assets	1,068,395	1,071,949
Assets	7,742,112	7,298,774	7,200,932
Current Liabilities:
Short-term debt	184,294	185,100
Current installments of long-term debt	779,597	490,268
Accounts payable	84,684	103,118
Customer deposits	9,173	10,585
Accrued interest and taxes	73,097	76,815
Regulatory liabilities	6,632	505
Operating lease liabilities	26,826	29,068
Dividends declared	24,625	24,625
Other current liabilities	62,651	47,397
Total current liabilities	1,251,579	967,481
Long-term Debt, net of Unamortized Premiums, Discounts, and Debt Issuance Costs	2,509,752	2,517,449
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	674,704	626,058
Regulatory liabilities	861,714	866,243
Asset retirement obligations	181,159	181,962
Accrued pension liability and postretirement benefit cost	86,170	95,037
Operating lease liabilities	81,933	105,512
Other deferred credits	250,977	185,753
Total deferred credits and other liabilities	2,136,657	2,060,565
Total liabilities	5,897,988	5,545,495
Commitments and Contingencies (Note 11)
Cumulative Preferred Stock of Subsidiary without mandatory redemption requirements ($100 stated value; 10,000,000 shares authorized; issued and outstanding 115,293 shares)	11,529	11,529
Company common stockholders’ equity:
Common stock	1,145,152	1,150,552
Accumulated other comprehensive income (loss), net of income taxes	(89,876)	(99,377)
Retained earnings	718,040	627,523
Total stockholders' equity	1,773,316	1,678,698
Non-controlling interest in Valencia	59,279	63,052
Total equity	1,832,595	1,741,750	1,735,088	1,752,594
Total liabilities and stockholders' equity	7,742,112	7,298,774
PNM
Current Assets:
Cash and cash equivalents	3,127	1,001	17,139	85
Accounts receivable, net of allowance for credit losses	100,914	60,447
Unbilled revenues	51,523	46,602
Other receivables	11,842	11,039
Affiliate receivables	8,867	8,825
Materials, supplies, and fuel stock	61,281	72,225
Regulatory assets	11,913	7,373
Income taxes receivable	15,602	15,122
Other current assets	37,661	36,561
Total current assets	302,730	259,195
Other Property and Investments:
Investment securities	408,551	388,832
Other investments	11	178
Non-utility property, net	9,083	4,470
Total other property and investments	417,645	393,480
Utility Plant:
Plant in service, held for future use, and to be abandoned	5,822,180	5,753,267
Less accumulated depreciation and amortization	2,137,415	2,076,291
Net plant in service and plant held for future use	3,684,765	3,676,976
Construction work in progress	227,721	108,787
Nuclear fuel, net of accumulated amortization	99,115	99,805
Net utility plant	4,011,601	3,885,568
Deferred Charges and Other Assets:
Regulatory assets	465,573	435,467
Goodwill	51,632	51,632
Operating lease right-of-use assets, net of accumulated amortization	103,251	120,585
Other deferred charges	96,806	97,064
Total deferred charges and other assets	717,262	704,748
Assets	5,449,238	5,242,991
Current Liabilities:
Short-term debt	21,700	58,000
Current installments of long-term debt	189,941	350,268
Accounts payable	60,310	66,746
Affiliate payables	10,698	12,524
Customer deposits	9,173	10,585
Accrued interest and taxes	44,661	43,617
Regulatory liabilities	6,032	371
Operating lease liabilities	24,282	25,927
Dividends declared	132	132
Other current liabilities	34,415	25,066
Total current liabilities	401,344	593,236
Long-term Debt, net of Unamortized Premiums, Discounts, and Debt Issuance Costs	1,656,046	1,397,752
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	564,256	521,990
Regulatory liabilities	670,574	683,398
Asset retirement obligations	180,223	181,081
Accrued pension liability and postretirement benefit cost	79,947	87,838
Operating lease liabilities	76,252	97,992
Other deferred credits	201,951	155,744
Total deferred credits and other liabilities	1,773,203	1,728,043
Total liabilities	3,830,593	3,719,031
Commitments and Contingencies (Note 11)
Cumulative Preferred Stock of Subsidiary without mandatory redemption requirements ($100 stated value; 10,000,000 shares authorized; issued and outstanding 115,293 shares)	11,529	11,529
Company common stockholders’ equity:
Common stock	1,264,918	1,264,918
Accumulated other comprehensive income (loss), net of income taxes	(88,745)	(99,055)
Retained earnings	371,664	283,516
Total stockholders' equity	1,547,837	1,449,379
Non-controlling interest in Valencia	59,279	63,052
Total equity	1,607,116	1,512,431	1,486,339	1,461,571
Total liabilities and stockholders' equity	5,449,238	5,242,991
Texas-New Mexico Power Company
Current Assets:
Cash and cash equivalents	26,000	1,000	0	0
Accounts receivable, net of allowance for credit losses	34,486	25,442
Unbilled revenues	12,798	10,814
Other receivables	2,948	2,713
Materials, supplies, and fuel stock	6,154	5,704
Other current assets	1,882	1,280
Total current assets	84,268	46,953
Other Property and Investments:
Other investments	178	178
Non-utility property, net	11,711	6,684
Total other property and investments	11,889	6,862
Utility Plant:
Plant in service, held for future use, and to be abandoned	2,031,222	1,919,256
Less accumulated depreciation and amortization	537,880	516,795
Net plant in service and plant held for future use	1,493,342	1,402,461
Construction work in progress	141,071	42,554
Net utility plant	1,634,413	1,445,015
Deferred Charges and Other Assets:
Regulatory assets	106,260	121,463
Goodwill	226,665	226,665
Operating lease right-of-use assets, net of accumulated amortization	7,876	9,954
Other deferred charges	3,920	3,527
Total deferred charges and other assets	344,721	361,609
Assets	2,075,291	1,860,439
Current Liabilities:
Short-term debt	494	15,000
Accounts payable	20,107	20,598
Affiliate payables	4,571	5,419
Accrued interest and taxes	54,394	42,068
Regulatory liabilities	600	134
Operating lease liabilities	2,341	2,753
Other current liabilities	5,407	3,565
Total current liabilities	87,914	89,537
Long-term Debt, net of Unamortized Premiums, Discounts, and Debt Issuance Costs	853,706	670,691
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	138,873	140,151
Regulatory liabilities	191,140	182,845
Asset retirement obligations	936	881
Accrued pension liability and postretirement benefit cost	6,223	7,199
Operating lease liabilities	5,311	7,039
Other deferred credits	23,987	7,469
Total deferred credits and other liabilities	366,470	345,584
Total liabilities	1,308,090	1,105,812
Commitments and Contingencies (Note 11)
Company common stockholders’ equity:
Common stock	64	64
Paid-in-capital	614,166	614,166
Retained earnings	152,971	140,397
Total stockholders' equity	767,201	754,627	$ 688,367	$ 674,093
Total liabilities and stockholders' equity	$ 2,075,291	$ 1,860,439