Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash Flows From Operating Activities:
Net Earnings	$ 31,078,000	$ 130,909,000	$ 115,556,000
Net Earnings	15,640,000	116,254,000	100,507,000
Adjustments to reconcile net earnings to net cash flows from operating activities:
Depreciation and amortization	222,861,000	209,867,000	208,173,000
Deferred income tax expense	16,451,000	72,481,000	60,430,000
Net unrealized (gains) losses on commodity derivatives	5,188,000	(6,504,000)	(1,866,000)
Realized (gains) on available-for-sale securities	(16,060,000)	(10,527,000)	(10,612,000)
Loss on reacquired debt	0	0	3,253,000
Stock based compensation expense	4,863,000	5,931,000	5,320,000
Regulatory disallowances and restructuring costs	167,471,000	1,062,000	12,235,000
Allowance for equity funds used during construction	(10,430,000)	(5,563,000)	(4,382,000)
Other, net	3,934,000	4,045,000	2,735,000
Changes in certain assets and liabilities:
Accounts receivable and unbilled revenues	(3,298,000)	(4,975,000)	(7,562,000)
Materials, supplies, and fuel stock	(180,000)	5,504,000	(7,580,000)
Other current assets	29,370,000	(30,436,000)	8,577,000
Other assets	2,369,000	290,000	(12,801,000)
Accounts payable	(32,269,000)	(2,311,000)	4,484,000
Accrued interest and taxes	4,957,000	2,040,000	91,537,000
Other current liabilities	2,633,000	(2,453,000)	(19,648,000)
Other liabilities	(42,064,000)	45,516,000	(61,262,000)
Net cash flows from operating activities	386,874,000	414,876,000	386,587,000
Cash Flows From Investing Activities:
Additions to utility and non-utility plant	(558,589,000)	(460,658,000)	(348,039,000)
Proceeds from sales of available-for-sale securities	252,174,000	117,989,000	271,140,000
Purchases of available-for-sale securities	(262,548,000)	(127,016,000)	(282,000,000)
Return of principal on PVNGS lessor notes	21,694,000	20,758,000	23,357,000
Purchase of Rio Bravo	0	(36,235,000)	0
Other, net	2,741,000	(167,000)	4,096,000
Net cash flows from investing activities	(544,528,000)	(485,329,000)	(331,446,000)
Cash Flows From Financing Activities:
Short-term loan	50,000,000	0	0
Revolving credit facilities borrowings (repayments), net	95,000,000	(43,600,000)	(9,500,000)
Long-term borrowings	463,605,000	355,000,000	75,000,000
Repayment of long-term debt	(333,066,000)	(125,000,000)	(29,468,000)
Cash paid in debt exchange	0	0	(13,048,000)
Proceeds from stock option exercise	5,619,000	6,999,000	4,618,000
Purchase of common stock	(17,720,000)	(17,319,000)	(13,807,000)
Dividends paid	(64,251,000)	(59,468,000)	(51,508,000)
Valencia’s transactions with its owner	(17,049,000)	(17,610,000)	(18,335,000)
Other, net	(6,707,000)	(2,808,000)	(5,545,000)
Net cash flows from financing activities	175,431,000	96,194,000	(61,593,000)
Change in Cash and Cash Equivalents	17,777,000	25,741,000	(6,452,000)
Cash and Cash Equivalents at Beginning of Year	28,274,000	2,533,000	8,985,000
Cash and Cash Equivalents at End of Year	46,051,000	28,274,000	2,533,000
Supplemental Cash Flow Disclosures:
Interest paid, net of amounts capitalized	103,382,000	108,741,000	110,768,000
Income taxes paid (refunded), net	(1,890,000)	(2,597,000)	(95,327,000)
Supplemental schedule of noncash investing and financing activities:
Changes in accrued plant additions	(19,080,000)	$ (3,089,000)	(6,006,000)
Premium on long-term debt incurred in connection with debt exchange			36,297,000
Public Service Company of New Mexico [Member]
Cash Flows From Operating Activities:
Net Earnings	(324,000)	$ 101,453,000	102,676,000
Net Earnings	(15,234,000)	87,326,000	88,155,000
Adjustments to reconcile net earnings to net cash flows from operating activities:
Depreciation and amortization	150,538,000	143,303,000	136,732,000
Deferred income tax expense	(2,836,000)	55,787,000	50,043,000
Net unrealized (gains) losses on commodity derivatives	5,188,000	(6,504,000)	(1,866,000)
Realized (gains) on available-for-sale securities	(16,060,000)	(10,527,000)	(10,612,000)
Regulatory disallowances and restructuring costs	167,471,000	1,062,000	12,235,000
Allowance for equity funds used during construction	(10,430,000)	(5,563,000)	(4,382,000)
Other, net	2,794,000	4,172,000	2,768,000
Changes in certain assets and liabilities:
Accounts receivable and unbilled revenues	(2,515,000)	(5,919,000)	(3,021,000)
Materials, supplies, and fuel stock	381,000	5,570,000	(7,730,000)
Other current assets	23,693,000	(29,146,000)	8,556,000
Other assets	4,194,000	7,150,000	(13,363,000)
Accounts payable	(31,139,000)	212,000	2,807,000
Accrued interest and taxes	(5,343,000)	(3,599,000)	72,740,000
Other current liabilities	(275,000)	(659,000)	(27,376,000)
Other liabilities	(33,503,000)	42,325,000	(59,753,000)
Net cash flows from operating activities	251,834,000	299,117,000	260,454,000
Cash Flows From Investing Activities:
Additions to utility and non-utility plant	(404,840,000)	(316,800,000)	(239,906,000)
Proceeds from sales of available-for-sale securities	252,174,000	117,989,000	271,140,000
Purchases of available-for-sale securities	(262,548,000)	(127,016,000)	(282,000,000)
Return of principal on PVNGS lessor notes	21,694,000	20,758,000	23,357,000
Purchase of Rio Bravo	0	(36,235,000)	0
Other, net	2,935,000	(363,000)	3,843,000
Net cash flows from investing activities	(390,585,000)	(341,667,000)	(223,566,000)
Cash Flows From Financing Activities:
Revolving credit facilities borrowings (repayments), net	0	(49,200,000)	28,100,000
Short-term borrowings (repayments) - affiliate, net	0	(32,500,000)	32,500,000
Long-term borrowings	313,605,000	275,000,000	75,000,000
Repayment of long-term debt	(214,300,000)	(75,000,000)	0
Equity contribution from parent	175,000,000	0	0
Dividends paid	(94,968,000)	(30,791,000)	(155,556,000)
Valencia’s transactions with its owner	(17,049,000)	(17,610,000)	(18,335,000)
Other, net	(5,879,000)	(1,890,000)	(2,534,000)
Net cash flows from financing activities	156,409,000	68,009,000	(40,825,000)
Change in Cash and Cash Equivalents	17,658,000	25,459,000	(3,937,000)
Cash and Cash Equivalents at Beginning of Year	25,480,000	21,000	3,958,000
Cash and Cash Equivalents at End of Year	43,138,000	25,480,000	21,000
Supplemental Cash Flow Disclosures:
Interest paid, net of amounts capitalized	69,936,000	73,787,000	71,306,000
Income taxes paid (refunded), net	(1,450,000)	(228,000)	(77,434,000)
Supplemental schedule of noncash investing and financing activities:
Changes in accrued plant additions	(17,469,000)	(1,616,000)	(7,921,000)
Texas-New Mexico Power Company [Member]
Cash Flows From Operating Activities:
Net Earnings	41,963,000	37,807,000	29,090,000
Adjustments to reconcile net earnings to net cash flows from operating activities:
Depreciation and amortization	57,909,000	52,847,000	54,395,000
Deferred income tax expense	20,883,000	20,549,000	20,662,000
Allowance for equity funds used during construction	0	0	0
Other, net	18,000	(10,000)	(30,000)
Changes in certain assets and liabilities:
Accounts receivable and unbilled revenues	(783,000)	944,000	(4,542,000)
Materials, supplies, and fuel stock	(561,000)	(66,000)	150,000
Other current assets	3,928,000	380,000	(1,137,000)
Other assets	(2,310,000)	(6,607,000)	941,000
Accounts payable	(1,782,000)	2,514,000	3,709,000
Accrued interest and taxes	4,317,000	4,796,000	(6,713,000)
Other current liabilities	1,019,000	(203,000)	(3,197,000)
Other liabilities	(9,823,000)	3,112,000	460,000
Net cash flows from operating activities	114,778,000	116,063,000	93,788,000
Cash Flows From Investing Activities:
Additions to utility and non-utility plant	(124,584,000)	(127,191,000)	(89,117,000)
Net cash flows from investing activities	(124,584,000)	(127,191,000)	(89,117,000)
Cash Flows From Financing Activities:
Revolving credit facilities borrowings (repayments), net	54,000,000	5,000,000	0
Short-term borrowings (repayments) - affiliate, net	(10,900,000)	(6,700,000)	1,100,000
Long-term borrowings	0	80,000,000	0
Repayment of long-term debt	0	(50,000,000)	0
Cash paid in debt exchange	0	0	(13,048,000)
Equity contribution from parent	0	0	13,800,000
Dividends paid	(33,248,000)	(16,336,000)	(3,726,000)
Other, net	(46,000)	(836,000)	(2,797,000)
Net cash flows from financing activities	9,806,000	11,128,000	(4,671,000)
Change in Cash and Cash Equivalents	0	0	0
Cash and Cash Equivalents at Beginning of Year	1,000	1,000	1,000
Cash and Cash Equivalents at End of Year	1,000	1,000	1,000
Supplemental Cash Flow Disclosures:
Interest paid, net of amounts capitalized	26,216,000	22,803,000	25,436,000
Income taxes paid (refunded), net	290,000	(355,000)	4,484,000
Supplemental schedule of noncash investing and financing activities:
Changes in accrued plant additions	5,000	$ (854,000)	141,000
Premium on long-term debt incurred in connection with debt exchange			36,297,000
Retained Earnings [Member]
Cash Flows From Operating Activities:
Net Earnings	16,168,000	$ 116,782,000	101,035,000
Cash Flows From Financing Activities:
Valencia’s transactions with its owner			0
Retained Earnings [Member] | Public Service Company of New Mexico [Member]
Cash Flows From Operating Activities:
Net Earnings	(15,234,000)	87,326,000	88,155,000
Cash Flows From Financing Activities:
Valencia’s transactions with its owner		0	0
Retained Earnings [Member] | Texas-New Mexico Power Company [Member]
Cash Flows From Operating Activities:
Net Earnings	$ 41,963,000	$ 37,807,000	$ 29,090,000