v3.25.4
Share-Based Compensation Plans - Narrative (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Granted (in shares) 0    
Weighted-Average grant date fair value of options granted (in dollars per share)     $ 27.45
Aggregate intrinsic value, exercised $ 55.0 $ 68.0 $ 52.0
Vested 109.0    
Exercisable $ 103.0    
Exercise period one      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting percentage (as a percent) 33.33%    
Exercise period two      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting percentage (as a percent) 33.33%    
Exercise period three      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting percentage (as a percent) 33.33%    
Restricted stock units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of shares of common stock to be issued per stock unit (in shares) 1    
Unrecognized compensation expense from unvested awards held by employees $ 92.0    
Weighted-average period for recognition of unrecognized compensation expense from unvested awards (in months) 19 months    
Longest period for recognition of unrecognized compensation expense from unvested awards (in months) 35 months    
Granted (in dollars per share) $ 128.09 $ 145.65 $ 100.39
Aggregate fair value, Issued shares $ 186.0 $ 206.0 $ 126.0
Restricted stock units | Employees Eligible for Retirement | Awards Granted in 2024      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting period 10 months    
Restricted stock units | Employees Eligible for Retirement | Awards Granted in 2023      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting period 10 months    
Performance share units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of shares of common stock to be issued per stock unit (in shares) 1    
Unrecognized compensation expense from unvested awards held by employees $ 0.0    
Granted (in dollars per share) $ 119.96 $ 130.22 $ 102.66
Aggregate fair value, Issued shares $ 12.0 $ 14.0 $ 13.0
Performance measurement period (in years) 3 years    
Fair value of cash settled units $ 106.0 $ 131.0 $ 36.0
Stock options      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation expense from unvested awards held by employees $ 0.3    
Weighted-average period for recognition of unrecognized compensation expense from unvested awards (in months) 3 months    
Longest period for recognition of unrecognized compensation expense from unvested awards (in months) 5 months    
Performance measurement period (in years) 3 years    
Stock option terms (in years) 10 years    
Weighted-average remaining contractual terms of vested options (in years) 5 years 2 months 12 days    
Weighted-average remaining contractual terms of exercisable options (in years) 5 years 21 days    
Cash received from the exercise of options $ 107.0    
Tax benefit from the exercise of options $ 12.0    
Stock options | Awards Granted in 2024      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Granted (in shares) 0 0  
Stock options | Awards Granted in 2023      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting period 10 months    
2013 Omnibus Stock and Performance Incentive Plan of Phillips 66      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Common stock issuable under P66 Omnibus Plan, maximum (in shares) 11,000,000    
2013 Omnibus Stock and Performance Incentive Plan of Phillips 66 | Restricted stock units | Cliff Vesting      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting period 3 years    
2013 Omnibus Stock and Performance Incentive Plan of Phillips 66 | Restricted stock units | Cliff Vesting, Awards Granted Prior to 2023      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting period     3 years