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Jointly Owned Utility Plant, Option to Purchase Proportionate Ownership Share

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Long Term Contract For Purchase of Electric Power Fixed Charges

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Long Term Contract for Purchae of Electric Power Variable Charges

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Long Term Contract For Purchase of Power Term of Contract

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Number of Mega Watts Purchased

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Operating Leases Currently Active with Trusts

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Operating Leases, Renewal Options After Original Lease Term

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Operating Leases, Trust Lessors

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Payments to acquire businesses, net

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Period of Long Term Contract For Purchase of Electric Power Fixed Costs

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Public Utilities, Power Plant Total Construction Costs

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Results of Operations Variable Interest Entity Operating Expenses

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Results of Operations Variable Interest Entity Operating Revenues

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- Definition

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer, acquired at the acquisition date.

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Amount of liabilities due within one year or within the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of assets expected to be realized or consumed after one year or the normal operating cycle, if longer, acquired at the acquisition date.

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Amount of liabilities due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of long-term debt due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

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The amount of property, plant, and equipment recognized as of the acquisition date.

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Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (that is, noncontrolling interest, previously referred to as minority interest).

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Variable Interest Entities (Details) (USD $)	3 Months Ended								12 Months Ended			6 Months Ended
Variable Interest Entities (Details) (USD $)	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 16, 2014	Oct. 08, 2013	May 30, 2008 MW	Jul. 17, 2014
Variable Interest Entity, Statement Of Operation [Abstract]
Earnings Attributable to non-controlling interest									$ 14,127,000	$ 14,521,000	$ 14,050,000
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Total current assets	432,817,000us-gaap_AssetsCurrent				401,539,000us-gaap_AssetsCurrent				432,817,000us-gaap_AssetsCurrent	401,539,000us-gaap_AssetsCurrent
Total Assets	5,829,325,000us-gaap_Assets				5,500,210,000us-gaap_Assets				5,829,325,000us-gaap_Assets	5,500,210,000us-gaap_Assets	5,372,583,000us-gaap_Assets
Current liabilities	704,282,000us-gaap_LiabilitiesCurrent				492,671,000us-gaap_LiabilitiesCurrent				704,282,000us-gaap_LiabilitiesCurrent	492,671,000us-gaap_LiabilitiesCurrent
Owners' equity - non-controlling interest	73,546,000us-gaap_MinorityInterest				77,029,000us-gaap_MinorityInterest				73,546,000us-gaap_MinorityInterest	77,029,000us-gaap_MinorityInterest
Operating Leases, renewal options after original lease term									6 years
Earnings Attributable to PNMR	18,992,000us-gaap_NetIncomeLoss	55,653,000us-gaap_NetIncomeLoss	29,141,000us-gaap_NetIncomeLoss	12,468,000us-gaap_NetIncomeLoss	7,648,000us-gaap_NetIncomeLoss	54,555,000us-gaap_NetIncomeLoss	27,678,000us-gaap_NetIncomeLoss	10,626,000us-gaap_NetIncomeLoss	116,254,000us-gaap_NetIncomeLoss	100,507,000us-gaap_NetIncomeLoss	105,547,000us-gaap_NetIncomeLoss
Public Service Company of New Mexico [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Operating Leases, Currently active with trusts	8								8
Operating Leases, trust lessors	8								8
Operating Leases, Different institutional investors of trust lessors	5								5
Operating Leases, renewal options after original lease term									2 years
Operating Leases, Extended lease term option									6 years
Operating leases, future minimum payments due	269,693,000								269,693,000
Operating Leases, Future Minimum Payments Due, Current	33,144,000								33,144,000
Earnings Attributable to PNMR	13,955,000	45,351,000	20,346,000	7,674,000	2,639,000	47,823,000	26,124,000	11,569,000
Valencia [Member] \| Public Service Company of New Mexico [Member]
Variable Interest Entity [Line Items]
Number of mega watts purchased (in megawatts)														158
Power plant total construction costs														90,000,000
Long term contract for purchase of electric power fixed costs									19,100,000	18,900,000	18,800,000
Long term contract for purchase of electric power variable charges									1,200,000	1,200,000	900,000
Variable Interest Entity, Statement Of Operation [Abstract]
Electric Revenue									20,247,000	20,166,000	19,585,000
Operating expenses									(6,120,000)	(5,645,000)	(5,535,000)
Earnings Attributable to non-controlling interest									(14,127,000)	(14,521,000)	(14,050,000)
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Total current assets	2,513,000				2,658,000				2,513,000	2,658,000
Net property, plant and equipment	72,321,000				75,137,000				72,321,000	75,137,000
Total Assets	74,834,000				77,795,000				74,834,000	77,795,000
Current liabilities	1,288,000				766,000				1,288,000	766,000
Owners' equity - non-controlling interest	73,546,000				77,029,000				73,546,000	77,029,000
Long term contract option to purchase, purchase price - percentage of adjusted NBV									50.00%
Long term contract option to purchase, purchase price - percentage of FMV		50.00%
Long term contract option to purchase, number of days to set FMV									60 days
Long term contract option to purchase, estimated purchase price													85,000,000
Long term contract option to purchase, approximate approval period									15 months
Long term contract option to purchase, ownership percentage									50.00%
Long Term Contract For Purchase of Power Term of Contract									20 years
Valencia [Member] \| Maximum [Member] \| Public Service Company of New Mexico [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Jointly owned utility plant, option to purchase proportionate ownership share	50.00%								50.00%
Delta [Member] \| Public Service Company of New Mexico [Member]
Variable Interest Entity [Line Items]
Long term contract for purchase of electric power fixed costs												3,500,000
Long term contract for purchase of electric power variable charges												600,000
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Period of Long Term Contract For Purchase of Electric Power Fixed Costs									20 years
PVNGS [Member] \| Public Service Company of New Mexico [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Operating leases, future minimum payments due	20,300,000								20,300,000
Operating leases, future minimum payments due, renewal term	145,200,000								145,200,000
Delta [Member] \| Public Service Company of New Mexico [Member]
Variable Interest Entity [Line Items]
Long term contract for purchase of electric power fixed costs										6,400,000	6,200,000
Long term contract for purchase of electric power variable charges										1,800,000	800,000
Delta [Member] \| Public Service Company of New Mexico [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Payments to acquire businesses, net												22,800,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt															14,600,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment															58,100,000
Business Combination, recognized identifiable assets acquired, accumulated amort															23,500,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets															3,600,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets															3,400,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities															300,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities															3,400,000
Palo Verde Nuclear Generating Station [Member] \| PVNGS [Member] \| Public Service Company of New Mexico [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Operating Leases, Future Minimum Payments Due, Current	$ 26,000,000				$ 26,000,000				$ 26,000,000	$ 26,000,000