Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 7,681	$ 46,051
Accounts receivable, net of allowance for uncollectible accounts	92,060	98,699
Unbilled revenues	57,705	52,012
Other receivables	17,715	28,590
Current portion of Westmoreland Loan	43,553	0
Materials, supplies, and fuel stock	72,015	67,386
Regulatory assets	7,558	1,070
Commodity derivative instruments	3,949	3,813
Income taxes receivable	6,904	5,845
Other current assets	89,746	82,104
Total current assets	398,886	385,570
Other Property and Investments:
Long-term portion of Westmoreland Loan	66,230	0
Available-for-sale securities	271,035	259,042
Other investments	428	604
Non-utility property	3,404	3,404
Total other property and investments	341,097	263,050
Utility Plant:
Plant in service, held for future use, and to be abandoned	6,842,017	6,307,261
Less accumulated depreciation and amortization	2,312,560	2,058,772
Net plant in service and plant held for future use	4,529,457	4,248,489
Construction work in progress	227,355	204,766
Nuclear fuel, net of accumulated amortization	87,083	82,117
Net utility plant	4,843,895	4,535,372
Deferred Charges and Other Assets:
Regulatory assets	463,016	470,664
Goodwill	278,297	278,297
Commodity derivative instruments	747	2,622
Other deferred charges	77,732	73,753
Total deferred charges and other assets	819,792	825,336
Total assets	6,403,670	6,009,328
Current Liabilities:
Short-term debt	355,900	250,600
Current installments of long-term debt	101,335	124,979
Accounts payable	76,403	100,419
Customer deposits	11,693	12,216
Accrued interest and taxes	80,180	58,306
Regulatory liabilities	6,403	15,591
Commodity derivative instruments	2,423	1,859
Dividends declared	17,656	17,656
Other current liabilities	49,833	59,494
Total current liabilities	701,826	641,120
Long-term Debt, net of Unamortized Premiums, Discounts, and Debt Issuance Costs	2,207,005	1,966,969
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	935,796	877,393
Regulatory liabilities	468,979	467,413
Asset retirement obligations	119,032	111,895
Accrued pension liability and postretirement benefit cost	63,437	73,097
Commodity derivative instruments	58	0
Other deferred credits	137,686	133,692
Total deferred credits and other liabilities	1,724,988	1,663,490
Total liabilities	4,633,819	4,271,579
Commitments and Contingencies (See Note 11)
Cumulative preferred stock of subsidiary without mandatory redemption requirements	11,529	11,529
Company common stockholders’ equity:
Common stock	1,162,599	1,166,465
Accumulated other comprehensive income (loss), net of income taxes	(73,643)	(71,432)
Retained earnings	599,249	559,780
Total stockholders' equity	1,688,205	1,654,813
Non-controlling interest in Valencia	70,117	71,407
Total equity	1,758,322	1,726,220
Total liabilities and stockholders' equity	6,403,670	6,009,328
Public Service Company of New Mexico [Member]
Current Assets:
Cash and cash equivalents	1,893	43,138
Accounts receivable, net of allowance for uncollectible accounts	63,109	78,291
Unbilled revenues	47,450	42,641
Other receivables	15,676	24,725
Affiliate receivables	8,956	15,105
Materials, supplies, and fuel stock	68,208	60,477
Regulatory assets	4,364	0
Commodity derivative instruments	3,949	3,813
Income taxes receivable	15,621	14,577
Other current assets	81,419	74,990
Total current assets	310,645	357,757
Other Property and Investments:
Available-for-sale securities	271,035	259,042
Other investments	197	366
Non-utility property	96	96
Total other property and investments	271,328	259,504
Utility Plant:
Plant in service, held for future use, and to be abandoned	5,303,910	4,833,303
Less accumulated depreciation and amortization	1,785,507	1,569,549
Net plant in service and plant held for future use	3,518,403	3,263,754
Construction work in progress	152,940	172,238
Nuclear fuel, net of accumulated amortization	87,083	82,117
Net utility plant	3,758,426	3,518,109
Deferred Charges and Other Assets:
Regulatory assets	335,025	342,910
Goodwill	51,632	51,632
Commodity derivative instruments	747	2,622
Other deferred charges	71,209	66,810
Total deferred charges and other assets	458,613	463,974
Total assets	4,799,012	4,599,344
Current Liabilities:
Short-term debt	42,400	0
Current installments of long-term debt	56,862	124,979
Accounts payable	59,003	72,386
Affiliate payables	15,082	14,318
Customer deposits	11,693	12,216
Accrued interest and taxes	50,379	33,189
Regulatory liabilities	6,403	15,591
Commodity derivative instruments	2,423	1,859
Dividends declared	132	132
Other current liabilities	31,606	42,251
Total current liabilities	275,983	316,921
Long-term Debt, net of Unamortized Premiums, Discounts, and Debt Issuance Costs	1,574,725	1,455,698
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	737,780	696,384
Regulatory liabilities	434,755	434,863
Asset retirement obligations	118,133	111,049
Accrued pension liability and postretirement benefit cost	57,057	66,285
Commodity derivative instruments	58	0
Other deferred credits	117,797	117,275
Total deferred credits and other liabilities	1,465,580	1,425,856
Total liabilities	3,316,288	3,198,475
Commitments and Contingencies (See Note 11)
Cumulative preferred stock of subsidiary without mandatory redemption requirements	11,529	11,529
Company common stockholders’ equity:
Common stock	1,264,918	1,236,776
Accumulated other comprehensive income (loss), net of income taxes	(73,240)	(71,476)
Retained earnings	209,400	152,633
Total stockholders' equity	1,401,078	1,317,933
Non-controlling interest in Valencia	70,117	71,407
Total equity	1,471,195	1,389,340
Total liabilities and stockholders' equity	4,799,012	4,599,344
Texas-New Mexico Power Company [Member]
Current Assets:
Cash and cash equivalents	3,018	1
Accounts receivable, net of allowance for uncollectible accounts	28,951	20,408
Unbilled revenues	10,255	9,371
Other receivables	1,129	811
Materials, supplies, and fuel stock	3,807	6,909
Regulatory assets	3,194	1,070
Other current assets	2,167	1,053
Total current assets	52,521	39,623
Other Property and Investments:
Other investments	231	238
Non-utility property	2,240	2,240
Total other property and investments	2,471	2,478
Utility Plant:
Plant in service, held for future use, and to be abandoned	1,342,081	1,285,727
Less accumulated depreciation and amortization	435,245	406,516
Net plant in service and plant held for future use	906,836	879,211
Construction work in progress	45,580	16,561
Net utility plant	952,416	895,772
Deferred Charges and Other Assets:
Regulatory assets	127,991	127,754
Goodwill	226,665	226,665
Other deferred charges	4,776	4,847
Total deferred charges and other assets	359,432	359,266
Total assets	1,366,840	1,297,139
Current Liabilities:
Short-term debt	0	59,000
Short-term debt – affiliate	0	11,800
Accounts payable	9,258	16,006
Affiliate payables	2,346	3,681
Accrued interest and taxes	55,788	32,891
Other current liabilities	3,012	2,044
Total current liabilities	70,404	125,422
Long-term Debt, net of Unamortized Premiums, Discounts, and Debt Issuance Costs	420,802	361,411
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	232,218	232,791
Regulatory liabilities	34,224	32,550
Asset retirement obligations	739	695
Accrued pension liability and postretirement benefit cost	6,380	6,812
Other deferred credits	4,841	4,078
Total deferred credits and other liabilities	278,402	276,926
Total liabilities	769,608	763,759
Commitments and Contingencies (See Note 11)
Company common stockholders’ equity:
Common stock	64	64
Paid-in-capital	454,166	404,166
Retained earnings	143,002	129,150
Total stockholders' equity	597,232	533,380
Total liabilities and stockholders' equity	$ 1,366,840	$ 1,297,139