XML 264 R100.htm IDEA: XBRL DOCUMENT v3.25.0.1
Short-term Borrowings and Long-term Debt - Narrative (Details)
$ / shares in Units, $ in Millions
1 Months Ended 12 Months Ended
Aug. 01, 2023
$ / shares
Oct. 31, 2024
USD ($)
Aug. 31, 2024
USD ($)
lawsuit
Dec. 31, 2024
USD ($)
period
shares
Debt Instrument [Line Items]        
Debt instrument, convertible, conversion ratio 27.1278      
Conversion price percentage 25.00%      
Houston Electric        
Debt Instrument [Line Items]        
Aggregate Principal       $ 1,400
Additional first mortgage bonds and general mortgage bonds that could be issued       $ 4,700
SIGECO        
Debt Instrument [Line Items]        
Percentage of property additions       70.00%
Long-term debt, gross       $ 985
Additional debt issuable       $ 899
Maximum        
Debt Instrument [Line Items]        
Debt instrument, convertible, conversion ratio       33.9097
Debt instrument, convertible, number of equity instruments (in shares) | shares       33,909,700
Junior Subordinated Notes | Maximum        
Debt Instrument [Line Items]        
Deferral period | period       20
Convertible Debt        
Debt Instrument [Line Items]        
Debt instrument, convertible, conversion price (in dollar per shares) | $ / shares $ 36.86      
Debt instrument, redemption price (as a percent) 100.00%      
General mortgage bonds, 2.35% to 6.95%, due 2026 to 2053 | Houston Electric        
Debt Instrument [Line Items]        
Secured debt       $ 8,400
Bonds Pollution Control Due | Houston Electric        
Debt Instrument [Line Items]        
Secured debt       $ 68
Percentage of property additions       70.00%
Series A Junior Subordinated Notes Due 2055 | Junior Subordinated Notes        
Debt Instrument [Line Items]        
Aggregate Principal     $ 400  
Series B Junior Subordinated Notes Due 2055 | Junior Subordinated Notes        
Debt Instrument [Line Items]        
Aggregate Principal     $ 400  
Series A, 7 Point Zero Percent, Junior Subordinated Notes Due 2030 | Junior Subordinated Notes        
Debt Instrument [Line Items]        
Basis spread (as a percent)     7.00%  
Debt Instrument, interest rate, period     5 years  
Number of days before interest rate period | lawsuit     2  
Series A, 3 Point 254 Percent, Junior Subordinated Notes Due 2030 | Junior Subordinated Notes        
Debt Instrument [Line Items]        
Basis spread (as a percent)     3.254%  
Series B, 6 Point 850 Percent, Junior Subordinated Notes Due 2030 | Junior Subordinated Notes        
Debt Instrument [Line Items]        
Basis spread (as a percent)     6.85%  
Series A Junior Subordinated Notes Due 2035 | Junior Subordinated Notes        
Debt Instrument [Line Items]        
Debt Instrument, interest rate, period     5 years  
Number of days before interest rate period | lawsuit     2  
Series B, 2 Point 946 Percent, Junior Subordinated Notes Due 2030 | Junior Subordinated Notes        
Debt Instrument [Line Items]        
Basis spread (as a percent)     2.946%  
Series C Junior Subordinated Notes Due 2055 | Junior Subordinated Notes        
Debt Instrument [Line Items]        
Aggregate Principal   $ 500    
Series A, 6 Point 700 Percent, Junior Subordinated Notes Due 2030 | Junior Subordinated Notes        
Debt Instrument [Line Items]        
Basis spread (as a percent)   6.70%    
Series A, 2 Point 586 Percent, Junior Subordinated Notes Due 2030 | Junior Subordinated Notes        
Debt Instrument [Line Items]        
Basis spread (as a percent)   2.586%