v3.25.0.1
Stock Plans: (Grant Date fair Value of Performance Share Units) (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Performance Share Units, Other Performance Factors      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted-Average PSU Grant Date Fair Value Subject to Performance Factors $ 29 $ 29 $ 30
Weighted-Average PSU Grant Date Fair Value Subject to Performance Factors (in dollars per share) $ 89.01 $ 102.02 $ 104.92
Performance Share Units, TSR Performance Factor      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted-Average PSU Grant Date Fair Value Subject to Performance Factors $ 19 $ 26 $ 27
Weighted-Average PSU Grant Date Fair Value Subject to Performance Factors (in dollars per share) $ 85.72 $ 133.54 $ 143.89
Performance Shares      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Compensation Expense related to PSU Awards $ 70 $ 59 $ 48