v3.26.3
Fair value measurement (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Jun. 30, 2026
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total derivative assets $ 410 $ 415
Debt instrument 9,483 7,167
Convertible Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt instrument 6,657 6,653
USPP Senior Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt instrument 1,542 515
GPU Financing    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt instrument 1,284  
Capped Call Transactions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total derivative assets 384 412
Interest-rate Swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total derivative assets 26 3
Quoted prices in active markets (Level 1)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total derivative assets 0 0
Debt instrument 6,489 7,484
Quoted prices in active markets (Level 1) | Convertible Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt instrument 6,489 7,484
Quoted prices in active markets (Level 1) | USPP Senior Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt instrument 0 0
Quoted prices in active markets (Level 1) | GPU Financing    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt instrument 0  
Quoted prices in active markets (Level 1) | Capped Call Transactions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total derivative assets 0 0
Quoted prices in active markets (Level 1) | Interest-rate Swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total derivative assets 0 0
Significant other observable inputs (Level 2)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total derivative assets 26 3
Debt instrument 2,839 524
Significant other observable inputs (Level 2) | Convertible Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt instrument 0 0
Significant other observable inputs (Level 2) | USPP Senior Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt instrument 1,547 524
Significant other observable inputs (Level 2) | GPU Financing    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt instrument 1,292  
Significant other observable inputs (Level 2) | Capped Call Transactions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total derivative assets 0 0
Significant other observable inputs (Level 2) | Interest-rate Swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total derivative assets 26 3
Significant unobservable inputs (Level 3)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total derivative assets 384 412
Debt instrument 0 0
Significant unobservable inputs (Level 3) | Convertible Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt instrument 0 0
Significant unobservable inputs (Level 3) | USPP Senior Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt instrument 0 0
Significant unobservable inputs (Level 3) | GPU Financing    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt instrument 0  
Significant unobservable inputs (Level 3) | Capped Call Transactions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total derivative assets 384 412
Significant unobservable inputs (Level 3) | Interest-rate Swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total derivative assets $ 0 $ 0