v3.26.1
Supplemental Financial Information - Supplemental Balance Sheet Information (Details) - USD ($)
 3 Months Ended 12 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Inventories, net    
Materials and supplies $ 2,200,000,000 $ 1,485,000,000
Natural gas, oil, and emission allowances 382,000,000 251,000,000
Inventories, net 2,582,000,000 1,736,000,000
Accounts payable and accrued expenses    
Accounts payable 2,708,000,000 2,813,000,000
Compensation-related accruals 557,000,000 920,000,000
Taxes accrued 484,000,000 246,000,000
Other accrued expenses 700,000,000 315,000,000
Total 4,449,000,000 4,294,000,000
Investments    
Equity method investments 26,000,000 3,000,000
Total 314,000,000 307,000,000
Employee benefit trusts and investments    
Investments    
Other investments: 110,000,000 112,000,000
Equity investments with readily determinable fair values    
Investments    
Other investments: 64,000,000 82,000,000
Equity investments without readily determinable fair values    
Investments    
Other investments: 113,000,000 109,000,000
Other available for sale debt security investments    
Investments    
Other investments: 1,000,000 1,000,000
Nonrelated Party    
Accounts payable and accrued expenses    
Total 4,449,000,000 4,294,000,000
Nuclear PTCs    
Accounts payable and accrued expenses    
Estimated nuclear PTCs credits used 0 375,000,000
Constellation Energy Generation, LLC    
Inventories, net    
Inventories, net 2,582,000,000 1,736,000,000
Accounts payable and accrued expenses    
Accounts payable 2,697,000,000 2,801,000,000
Compensation-related accruals 445,000,000 672,000,000
Taxes accrued 483,000,000 245,000,000
Other accrued expenses 699,000,000 315,000,000
Constellation Energy Generation, LLC | Nonrelated Party    
Accounts payable and accrued expenses    
Total $ 4,324,000,000 $ 4,033,000,000