v3.26.1
Fair Value of Financial Information - Measurements of Assets and Liabilities on Recurring Basis (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Assets:    
Restricted funds $ 37 $ 41
Rabbi trust investments 36 32
Deposits 139 124
Mark-to-market derivative asset   2
Total assets 248 254
Liabilities:    
Deferred compensation obligations 39 38
Total liabilities 39 38
Total assets 209 216
Fixed-income securities    
Assets:    
Other investments 3 35
Money market and other    
Assets:    
Other investments 33 20
Level 1    
Assets:    
Restricted funds 37 41
Rabbi trust investments 36 32
Deposits 139 124
Mark-to-market derivative asset   0
Total assets 246 245
Liabilities:    
Deferred compensation obligations 39 38
Total liabilities 39 38
Total assets 207 207
Level 1 | Fixed-income securities    
Assets:    
Other investments 1 28
Level 1 | Money market and other    
Assets:    
Other investments 33 20
Level 2    
Assets:    
Restricted funds 0 0
Rabbi trust investments 0 0
Deposits 0 0
Mark-to-market derivative asset   2
Total assets 2 9
Liabilities:    
Deferred compensation obligations 0 0
Total liabilities 0 0
Total assets 2 9
Level 2 | Fixed-income securities    
Assets:    
Other investments 2 7
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
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