Fair Value of Derivative and Other Financial Instruments, Derivative Balance Sheet Information (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Commodity derivative instruments, Current assets	$ 11,232,000us-gaap_DerivativeAssetsCurrent	$ 4,064,000us-gaap_DerivativeAssetsCurrent
Commodity derivative instruments, Deferred charges	0us-gaap_DerivativeAssetsNoncurrent	3,002,000us-gaap_DerivativeAssetsNoncurrent
Commodity derivative instruments, Current liabilities	(1,209,000)us-gaap_DerivativeLiabilitiesCurrent	(2,699,000)us-gaap_DerivativeLiabilitiesCurrent
Commodity derivative instruments, Long-term liabilities	(477,000)us-gaap_DerivativeLiabilitiesNoncurrent	(1,094,000)us-gaap_DerivativeLiabilitiesNoncurrent
PNMR and PNM [Member]
Derivatives, Fair Value [Line Items]
Derivative, Collateral, Right to Reclaim Cash	0
Margin Deposit Assets	3,800,000	2,800,000
Derivative, Collateral, Obligation to Return Cash	200,000	200,000
PNMR and PNM [Member] \| Economic hedges [Member] \| Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Commodity derivative instruments, Current assets	11,232,000	4,064,000
Commodity derivative instruments, Deferred charges	0	3,002,000
Commodity derivative instruments, Assets	11,232,000	7,066,000
Commodity derivative instruments, Current liabilities	(1,209,000)	(2,699,000)
Commodity derivative instruments, Long-term liabilities	(477,000)	(1,094,000)
Commodity derivative instruments, Liabilities	(1,686,000)	(3,793,000)
Commodity derivative instruments, Net	9,546,000	3,273,000
PNMR and PNM [Member] \| Designated as Hedging Instrument [Member] \| Commodity Contract [Member] \| Palo Verde Nuclear Generating Station [Member]
Derivatives, Fair Value [Line Items]
Commodity derivative instruments, Current assets	3,000,000	3,000,000
Commodity derivative instruments, Deferred charges		3,000,000
Public Service Company of New Mexico [Member] \| Economic hedges [Member] \| Commodity Contract [Member] \| Fuel and purchased power adjustment clause [Member]
Derivatives, Fair Value [Line Items]
Commodity derivative instruments, Current assets	0	400,000
Commodity derivative instruments, Current liabilities		$ (100,000)

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

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Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets.

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Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

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The amount of cash or securities placed with a broker or counterparty as security for a trading or derivatives securities position which was partially obtained with funds provided by the broker dealer.

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