v3.25.1
Fair Value of Financial Information - Measurements of Assets and Liabilities on Recurring Basis (Details) - USD ($)
$ in Millions
Mar. 31, 2025
Dec. 31, 2024
Assets:    
Restricted funds $ 43 $ 44
Rabbi trust investments 28 29
Deposits 7 6
Mark-to-market derivative asset 10 24
Total assets 193 218
Liabilities:    
Deferred compensation obligations 33 34
Total liabilities 33 34
Total assets 160 184
Fixed-income securities    
Assets:    
Other investments 84 94
Money market and other    
Assets:    
Other investments 21 21
Level 1    
Assets:    
Restricted funds 43 44
Rabbi trust investments 28 29
Deposits 7 6
Mark-to-market derivative asset 0 0
Total assets 176 188
Liabilities:    
Deferred compensation obligations 33 34
Total liabilities 33 34
Total assets 143 154
Level 1 | Fixed-income securities    
Assets:    
Other investments 77 88
Level 1 | Money market and other    
Assets:    
Other investments 21 21
Level 2    
Assets:    
Restricted funds 0 0
Rabbi trust investments 0 0
Deposits 0 0
Mark-to-market derivative asset 10 24
Total assets 17 30
Liabilities:    
Deferred compensation obligations 0 0
Total liabilities 0 0
Total assets 17 30
Level 2 | Fixed-income securities    
Assets:    
Other investments 7 6
Level 2 | Money market and other    
Assets:    
Other investments 0 0
Level 3    
Assets:    
Restricted funds 0 0
Rabbi trust investments 0 0
Deposits 0 0
Mark-to-market derivative asset 0 0
Total assets 0 0
Liabilities:    
Deferred compensation obligations 0 0
Total liabilities 0 0
Total assets 0 0
Level 3 | Fixed-income securities    
Assets:    
Other investments 0 0
Level 3 | Money market and other    
Assets:    
Other investments $ 0 $ 0