XML 72 R56.htm IDEA: XBRL DOCUMENT v3.21.2
Financing - Short-term Debt and Liquidity (Details)
 6 Months Ended 12 Months Ended
Jun. 30, 2021
USD ($)
extension_option
Dec. 31, 2017
USD ($)
derivative
Jul. 23, 2021
USD ($)
Mar. 23, 2021
Dec. 31, 2020
USD ($)
Short-term Debt [Line Items]          
Financing capacity $ 40,000,000.0        
Short-term debt 91,500,000       $ 32,000,000
Letters of credit outstanding 3,300,000        
Notes payable, related parties $ 0       0
Variable Rate Short-Term Debt          
Short-term Debt [Line Items]          
Term of derivatives   4 years      
Aggregate principal amount   $ 50,000,000.0      
TNMP Revolving Credit Facility          
Short-term Debt [Line Items]          
Line of credit facility, interest rate at period end 0.84%        
PNMR Revolving Credit Facility          
Short-term Debt [Line Items]          
Short-term debt $ 53,300,000       12,000,000
PNMR Revolving Credit Facility | PNMR          
Short-term Debt [Line Items]          
Line of credit facility, interest rate at period end 1.59%        
PNMR Development Revolving Credit Facility          
Short-term Debt [Line Items]          
Short-term debt $ 0       10,000,000
PNM          
Short-term Debt [Line Items]          
Short-term debt 0       10,000,000
Letters of credit outstanding 2,200,000        
Notes payable, related parties 0       0
PNM | Lines of credit          
Short-term Debt [Line Items]          
NMPRC approved credit facility 40,000,000.0        
PNM | Senior Unsecured Notes PCRB, Reprice Date of October 2021 | Senior Unsecured Notes, Pollution Control Revenue Bonds          
Short-term Debt [Line Items]          
Unsecured long-term debt, noncurrent 146,000,000.0        
PNM | Senior Unsecured Notes PCRB, Reprice Date of June 2022 | Senior Unsecured Notes, Pollution Control Revenue Bonds          
Short-term Debt [Line Items]          
Unsecured long-term debt, noncurrent 104,500,000        
PNM | PNM 2017 New Mexico Credit Facility          
Short-term Debt [Line Items]          
Short-term debt 0       10,000,000
Letters of credit outstanding 0        
PNM | PNM Revolving Credit Facility          
Short-term Debt [Line Items]          
Letters of credit outstanding 0        
TNMP          
Short-term Debt [Line Items]          
Short-term debt 38,200,000       0
Letters of credit outstanding 0        
Notes payable, related parties 0       0
TNMP | TNMP Revolving Credit Facility          
Short-term Debt [Line Items]          
Short-term debt 38,200,000       0
PNMR Development          
Short-term Debt [Line Items]          
Notes payable, related parties 0       $ 300,000
Revolving credit facility          
Short-term Debt [Line Items]          
Financing capacity 300,000,000.0        
Revolving credit facility | PNM          
Short-term Debt [Line Items]          
Financing capacity 400,000,000.0        
Revolving credit facility | TNMP          
Short-term Debt [Line Items]          
Financing capacity 75,000,000.0        
Revolving credit facility | TNMP | First mortgage bonds          
Short-term Debt [Line Items]          
Collateral amount $ 75,000,000.0        
Number of extension options | extension_option 2        
Extension option period 1 year        
Interest rate contract          
Short-term Debt [Line Items]          
Number of derivatives | derivative   3      
Interest rate 1 | Variable Rate Short-Term Debt          
Short-term Debt [Line Items]          
Fixed interest rate   1.926%   1.926%  
Interest rate 2 | Variable Rate Short-Term Debt          
Short-term Debt [Line Items]          
Fixed interest rate   1.823%      
Interest rate 3 | Variable Rate Short-Term Debt          
Short-term Debt [Line Items]          
Fixed interest rate   1.629%      
Subsequent event          
Short-term Debt [Line Items]          
Notes payable, related parties     $ 0    
Remaining borrowing capacity     715,200,000    
Subsequent event | PNMR          
Short-term Debt [Line Items]          
Remaining borrowing capacity     258,900,000    
Consolidated invested cash     900,000    
Subsequent event | Pollution Control Revenue Bonds | Bonds          
Short-term Debt [Line Items]          
Aggregate principal amount     100,300,000    
Subsequent event | PNM          
Short-term Debt [Line Items]          
Notes payable, related parties     0    
Remaining borrowing capacity     397,800,000    
Consolidated invested cash     21,700,000    
Subsequent event | PNM | Lines of credit          
Short-term Debt [Line Items]          
Remaining borrowing capacity     40,000,000.0    
Subsequent event | TNMP          
Short-term Debt [Line Items]          
Notes payable, related parties     0    
Remaining borrowing capacity     18,500,000    
Consolidated invested cash     0    
Subsequent event | PNMR Development          
Short-term Debt [Line Items]          
Notes payable, related parties     $ 0