v3.26.1
Debt and Credit Agreements - Narrative (Details)
$ in Millions
1 Months Ended 2 Months Ended 3 Months Ended
Apr. 30, 2026
USD ($)
Mar. 31, 2026
USD ($)
Feb. 28, 2026
USD ($)
Jan. 31, 2026
USD ($)
plant
Nov. 30, 2025
USD ($)
Sep. 30, 2025
Feb. 28, 2026
Mar. 31, 2026
USD ($)
Mar. 31, 2025
USD ($)
Jan. 07, 2026
USD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Line of Credit Facility [Line Items]                        
Repayments of debt               $ 5,254 $ 57      
Maximum borrowing capacity   $ 15,050           15,050     $ 9,458  
Senior unsecured notes                        
Line of Credit Facility [Line Items]                        
Issued Amount   2,290           2,290        
Calpine                        
Line of Credit Facility [Line Items]                        
Debt assumed       $ 12,600           $ 12,272    
Calpine | Senior unsecured notes                        
Line of Credit Facility [Line Items]                        
Issued Amount       2,300                
Corporate Debt                        
Line of Credit Facility [Line Items]                        
Repayments of debt       2,500                
Corporate Debt | Calpine                        
Line of Credit Facility [Line Items]                        
Debt assumed       7,600                
Corporate Debt | Calpine | Secured Debt                        
Line of Credit Facility [Line Items]                        
Maximum borrowing capacity       525                
Corporate Debt | Calpine | Unsecured Debt                        
Line of Credit Facility [Line Items]                        
Maximum borrowing capacity       200                
Various Non-recourse Debt and Project Financing Arrangements | Calpine                        
Line of Credit Facility [Line Items]                        
Debt assumed       5,000                
Senior Secured First Lien Notes                        
Line of Credit Facility [Line Items]                        
Repayments of debt   1,400 $ 1,250                  
GPC First-Lien Senior Secured Term Loan Facility                        
Line of Credit Facility [Line Items]                        
Repayments of debt               $ 35        
Basis spread               1.625%        
GPC First-Lien Senior Secured Term Loan Facility | Calpine                        
Line of Credit Facility [Line Items]                        
Debt assumed       1,350                
Maximum borrowing capacity       250                
Loan agreement   1,300           $ 1,300        
Basis spread               1.625%        
GPC First-Lien Senior Secured Term Loan, Sub-Facility | Calpine                        
Line of Credit Facility [Line Items]                        
Debt assumed       45                
Maximum borrowing capacity       50                
Loan agreement   44           $ 44        
CCFC First-Lien Senior Secured Term Loan Facility | Calpine                        
Line of Credit Facility [Line Items]                        
Debt assumed       $ 2,100                
Loan agreement   2,100           $ 2,100        
Basis spread               1.75%        
Number of natural gas powered plants | plant       7                
CDHI Revolver                        
Line of Credit Facility [Line Items]                        
Decrease in total capacity   (250)                    
CDHI Revolver | Subsequent Event                        
Line of Credit Facility [Line Items]                        
Decrease in total capacity $ (568)                      
CDHI Revolver | Calpine                        
Line of Credit Facility [Line Items]                        
Debt assumed       $ 1,200                
Loan agreement   $ 309   319       $ 309        
Basis spread   2.375%         2.25%          
CDHI Revolver, Renewable Energy Project Construction | Calpine                        
Line of Credit Facility [Line Items]                        
Debt assumed       400                
Nova Power Credit Agreement                        
Line of Credit Facility [Line Items]                        
Repayments of debt               $ 10        
Basis spread               1.75%        
Nova Power Credit Agreement | Calpine                        
Line of Credit Facility [Line Items]                        
Debt assumed       80                
Loan agreement   $ 581   591       $ 581        
Basis spread               1.75%        
Greenfield L.P. Loan Facility                        
Line of Credit Facility [Line Items]                        
Repayments of debt               $ 7        
Basis spread               1.875%        
Greenfield L.P. Loan Facility | Calpine                        
Line of Credit Facility [Line Items]                        
Debt assumed       75                
Loan agreement   $ 330   342       $ 330        
Basis spread               1.875%        
Pin Oak Creek Energy Center                        
Line of Credit Facility [Line Items]                        
Interest Rate   300.00%           300.00%        
Pin Oak Creek Energy Center | Calpine                        
Line of Credit Facility [Line Items]                        
Loan agreement   $ 246   230       $ 246        
Interest Rate   3.00%           3.00%        
Letter of credit | Calpine                        
Line of Credit Facility [Line Items]                        
Loan agreement       1,700                
Senior Unsecured Notes | Unsecured Debt                        
Line of Credit Facility [Line Items]                        
Issued Amount       $ 2,750                
DOE Loan Program | Unsecured Debt                        
Line of Credit Facility [Line Items]                        
Issued Amount         $ 1,000              
Basis spread         0.375%              
Maximum | Senior unsecured notes                        
Line of Credit Facility [Line Items]                        
Interest Rate   6.50%           6.50%        
Daily Simple SOFR Rate | Maximum | Non-investment grade                        
Line of Credit Facility [Line Items]                        
Basis spread               1.00%        
Term SOFR Rate | Maximum | Non-investment grade                        
Line of Credit Facility [Line Items]                        
Basis spread               2.00%        
Revolving Credit Facility                        
Line of Credit Facility [Line Items]                        
Maximum borrowing capacity   $ 7,000           $ 7,000     4,500  
Aggregate commitments available including incremental commitments   7,000           7,000        
Incremental commitments   $ 2,500           $ 2,500        
Line of credit facility, fee rate           0.175%            
Revolving Credit Facility | Daily Simple SOFR Rate                        
Line of Credit Facility [Line Items]                        
Basis spread           0.075%            
Revolving Credit Facility | Term SOFR Rate                        
Line of Credit Facility [Line Items]                        
Basis spread           1.075%            
Letter of credit                        
Line of Credit Facility [Line Items]                        
Interest Rate   1.075%           1.075%        
Accounts Receivable Facility                        
Line of Credit Facility [Line Items]                        
Maximum borrowing capacity   $ 1,500           $ 1,500     $ 1,500 $ 1,500
Proceeds from Lines of Credit   $ 900 $ 600                  
Accounts Receivable Facility | Subsequent Event                        
Line of Credit Facility [Line Items]                        
Repayments of facility $ 400                      
Accounts Receivable Facility | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate                        
Line of Credit Facility [Line Items]                        
Basis spread               0.10%