XML 77 R57.htm IDEA: XBRL DOCUMENT v3.5.0.2
Regulatory and Rate Matters - TNMP Narrative (Details) - Texas-New Mexico Power Company [Member]
 1 Months Ended 6 Months Ended
Jul. 27, 2016
USD ($)
Jul. 19, 2016
USD ($)
May 27, 2016
USD ($)
Jul. 30, 2011
USD ($)
Sep. 09, 2016
USD ($)
Jun. 30, 2016
USD ($)
Mar. 22, 2016
USD ($)
Sep. 09, 2015
USD ($)
Mar. 15, 2015
USD ($)
Aug. 05, 2016
customer
Oct. 02, 2015
USD ($)
Aug. 15, 2013
USD ($)
customer
Advanced Meter System Deployment and Surcharge Request [Member]                        
Public Utilities, General Disclosures [Line Items]                        
Approved deployment costs       $ 113,400,000                
Collection of deployment costs through surcharge period       12 years                
Completion period of advanced meter deployment       5 years                
Recovery in cost through initial fees                       $ 200,000
Ongoing annual expenses                       500,000
Approved non-standard metering ongoing expenses monthly charge                       $ 36.78
Presumed number of customers that will elect non-standard meter service (in customers) | customer                       1,081
Cost and savings reconciliation filed with regulators, capital cost savings                     $ 71,000,000  
Cost and savings reconciliation filed with regulators, operations and maintenance savings                     $ 18,000,000  
Program costs incurred to date           $ 1,500,000            
Advanced Meter System Deployment and Surcharge Request [Member] | Subsequent Event [Member]                        
Public Utilities, General Disclosures [Line Items]                        
Current number of customers that have elected non-standard meter service (in customers) | customer                   101    
Advanced Meter System Deployment and Surcharge Request [Member] | Minimum [Member]                        
Public Utilities, General Disclosures [Line Items]                        
Approved non-standard metering service cost, initial fee range                       $ 63.97
Advanced Meter System Deployment and Surcharge Request [Member] | Maximum [Member]                        
Public Utilities, General Disclosures [Line Items]                        
Approved non-standard metering service cost, initial fee range                       $ 168.61
Transmission Cost of Service Rates [Member]                        
Public Utilities, General Disclosures [Line Items]                        
Annual increase in revenue             $ 1,400,000 $ 4,400,000 $ 4,200,000      
Transmission Cost of Service Rates [Member] | Subsequent Event [Member]                        
Public Utilities, General Disclosures [Line Items]                        
Requested rate increase (decrease)   $ 9,500,000                    
Annual increase in revenue   $ 1,800,000     $ 4,300,000              
Energy Efficiency [Member]                        
Public Utilities, General Disclosures [Line Items]                        
Requested adjustment to EECRF     $ 6,100,000                  
Requested adjustment to EECRF, performance bonus     $ 800,000                  
Energy Efficiency [Member] | Subsequent Event [Member]                        
Public Utilities, General Disclosures [Line Items]                        
Approved program cost recovery $ 6,000,000                      
Approved performance bonus $ 800,000