XML 77 R46.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Regulatory and Rate Matters Regulatory and Rate Matters (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2017
Regulated Operations [Abstract] |
Schedule of Energy/Capacity Transactions | Information about PNM’s purchases and sales is as follows:
| Sales |  | Purchases
| GWh |  | Amount |  | GWh |  | Amount
|  |  | (In millions) |  |  |  | (In millions)
Year ended December 31, 2017 | 827.1 |  |  | $ | 23.6 |  |  | 849.0 |  |  | $ | 24.2 |
Year ended December 31, 2016 | 482.3 |  |  | 12.8 |  |  | 484.6 |  |  | 12.9 |
Schedule of Rate Increases for Transmission Costs | TNMP can update its transmission rates twice per year to reflect changes in its invested capital although updates are not allowed while a general rate case is in progress. Updated rates reflect the addition and retirement of transmission facilities, including appropriate depreciation, federal income tax and other associated taxes, and the approved rate of return on such facilities. The following sets forth TNMP’s recent interim transmission cost rate increases:
Effective Date |  | Approved Increase in Rate Base |  | Annual Increase in Revenue
|  | (In millions)
March 16, 2015 |  | $ | 27.1 |  |  | $ | 4.4 |
September 10, 2015 |  | 7.0 |  |  | 1.4 |
March 23, 2016 |  | 25.8 |  |  | 4.3 |
September 8, 2016 |  | 9.5 |  |  | 1.8 |
March 14, 2017 |  | 30.2 |  |  | 4.8 |
September 13, 2017 |  | 27.5 |  |  | 4.7 |
TNMP recovers the costs of its energy efficiency programs through an energy efficiency cost recovery factor (“EECRF”), which includes projected program costs, under or over collected costs from prior years, rate case expenses, and performance bonuses (if the programs exceed mandated savings goals). The following sets forth TNMP’s EECRF increases:
Effective Date |  | Aggregate Collection Amount |  | Performance Bonus
|  | (In millions)
March 1, 2015 |  | $ | 5.7 |  |  | $ | 1.5 |
March 1, 2016 |  | 6.0 |  |  | 0.7 |
March 1, 2017 |  | 6.0 |  |  | 0.8 |
March 1, 2018 |  | 6.0 |  |  | 1.1 |

X
- Definition Schedule of Energy/Capacity Transactions [Table Text Block] + References No definition available. + Details
Name: | pnm_ScheduleofEnergyCapacityTransactionsTableTextBlock
Namespace Prefix: | pnm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of Rate Increases for Transmission Costs [Table Text Block] + References No definition available. + Details
Name: | pnm_ScheduleofRateIncreasesforTransmissionCostsTableTextBlock
Namespace Prefix: | pnm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_RegulatedOperationsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration