v3.25.2
Pension and Other Postretirement Benefits - Schedule of Plan Assets and Grantor Trust Assets By Level (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2023
Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset $ 265 $ 266  
Money market funds | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 8 26  
Domestic fixed income funds | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 68 66  
Balanced funds | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 60 53  
Domestic government obligations | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 128 120  
Other | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 1 1  
Pension benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 904 891 $ 853
Pension benefits | Money market funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 35 12  
Pension benefits | Domestic equity funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 116 156  
Pension benefits | Domestic fixed income funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 582 488  
Pension benefits | International equity funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 83 118  
Pension benefits | Balanced funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 55 69  
Pension benefits | Partnership interests      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 33 48  
Level 1 | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 265 266  
Level 1 | Money market funds | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 8 26  
Level 1 | Domestic fixed income funds | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 68 66  
Level 1 | Balanced funds | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 60 53  
Level 1 | Domestic government obligations | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 128 120  
Level 1 | Other | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 1 1  
Level 1 | Pension benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 871 843  
Level 1 | Pension benefits | Money market funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 35 12  
Level 1 | Pension benefits | Domestic equity funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 116 156  
Level 1 | Pension benefits | Domestic fixed income funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 582 488  
Level 1 | Pension benefits | International equity funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 83 118  
Level 1 | Pension benefits | Balanced funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 55 69  
Level 1 | Pension benefits | Partnership interests      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 0 0  
Fair Value Measured at Net Asset Value Per Share | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 0 0  
Fair Value Measured at Net Asset Value Per Share | Money market funds | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 0 0  
Fair Value Measured at Net Asset Value Per Share | Domestic fixed income funds | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 0 0  
Fair Value Measured at Net Asset Value Per Share | Balanced funds | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 0 0  
Fair Value Measured at Net Asset Value Per Share | Domestic government obligations | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 0 0  
Fair Value Measured at Net Asset Value Per Share | Other | Trust for Benefit of Employees      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 0 0  
Fair Value Measured at Net Asset Value Per Share | Pension benefits      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 33 48  
Fair Value Measured at Net Asset Value Per Share | Pension benefits | Money market funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 0 0  
Fair Value Measured at Net Asset Value Per Share | Pension benefits | Domestic equity funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 0 0  
Fair Value Measured at Net Asset Value Per Share | Pension benefits | Domestic fixed income funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 0 0  
Fair Value Measured at Net Asset Value Per Share | Pension benefits | International equity funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 0 0  
Fair Value Measured at Net Asset Value Per Share | Pension benefits | Balanced funds      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset 0 0  
Fair Value Measured at Net Asset Value Per Share | Pension benefits | Partnership interests      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan asset $ 33 $ 48