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Public Utilities, Number of Mega Watts of Solar Photovoltaic Capacity, Current Output

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Public Utilities, Number of Mega Watts of Wind Energy Capacity

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Reasonable Cost Threshold

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Public Utilities, Renewable Energy Procurement Plan, Requested Additional Megawatt Hours, Year 1

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Public Utilities, Renewable Energy Procurement Plan, Requested Additional Megawatt Hours, Year 2

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Public Utilities, Renewable Energy Procurement Plan, Requested Solar Facility Construction, Megawatts

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Regulated Operations, Required Percentage of Diversification

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Public Utilities, Solar generation capacity in Megawatts

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Regulatory and Rate Matters - Renewable Portfolio Standard (Details) - Public Service Company of New Mexico	12 Months Ended
	Dec. 31, 2017 MW	Dec. 31, 2016 MW	Jun. 01, 2017 GWh MW	Dec. 31, 2015 MW	Dec. 31, 2013 MW
Renewable Portfolio Standard
Public Utilities, General Disclosures [Line Items]
Solar photovoltaic capacity (in mw)	107			40
Current output of solar photovoltaic capacity (in mw)	4
Solar distributed generation (in mw)	81.6
Renewable Portfolio Standard \| Minimum
Public Utilities, General Disclosures [Line Items]
Reasonable cost threshold	3.00%
Renewable Portfolio Standard \| Minimum \| Wind
Public Utilities, General Disclosures [Line Items]
Required percentage of diversification	30.00%
Renewable Portfolio Standard \| Minimum \| Solar
Public Utilities, General Disclosures [Line Items]
Required percentage of diversification	20.00%
Renewable Portfolio Standard \| Minimum \| Distributed Generation
Public Utilities, General Disclosures [Line Items]
Required percentage of diversification	3.00%
Renewable Portfolio Standard \| Minimum \| Other
Public Utilities, General Disclosures [Line Items]
Required percentage of diversification	5.00%
Renewable Portfolio Standard \| Required Percentage by 2011
Public Utilities, General Disclosures [Line Items]
Required percentage of renewable energy in portfolio to electric sales	10.00%
Renewable Portfolio Standard \| Required Percentage by 2015
Public Utilities, General Disclosures [Line Items]
Required percentage of renewable energy in portfolio to electric sales	15.00%
Renewable Portfolio Standard \| Required Percentage by 2020
Public Utilities, General Disclosures [Line Items]
Required percentage of renewable energy in portfolio to electric sales	20.00%
Renewable Portfolio Standard Supplemental Procurement
Public Utilities, General Disclosures [Line Items]
Solar photovoltaic capacity (in mw)					1.5
Renewable Portfolio Standard 2014
Public Utilities, General Disclosures [Line Items]
Wind energy capacity (in mw)	204	102
NMPRC
Public Utilities, General Disclosures [Line Items]
Additional megawatt hours in first year (in mw) \| GWh			80
Requested solar production (in mw)			50
New Mexico Wind \| NMPRC
Public Utilities, General Disclosures [Line Items]
Additional megawatt hours in second year (in mw) \| GWh			105
Lightning Dock Geothermal \| NMPRC
Public Utilities, General Disclosures [Line Items]
Additional megawatt hours in first year (in mw) \| GWh			55
Additional megawatt hours in second year (in mw) \| GWh			77