v3.26.1
Debt - Long-term debt (Details)
€ in Millions, $ in Millions
Jun. 30, 2026
USD ($)
Jun. 30, 2026
EUR (€)
Dec. 31, 2025
USD ($)
Long-term debt [Line Items]      
Total $ 12,676   $ 12,712
Less current maturities (1,461)   (588)
Long-term debt 11,215   12,124
Senior Notes due 2055, $1,000 million, 4.625% ($15 million of discount; $10 million of debt issuance cost)      
Long-term debt [Line Items]      
Face amount $ 1,000    
Stated interest rate (in percent) 4.625% 4.625%  
Unamortized discount $ 15    
Unamortized debt issuance cost 10    
Total 975   975
Guaranteed Notes due 2027, $300 million, 8.1%      
Long-term debt [Line Items]      
Face amount $ 300    
Stated interest rate (in percent) 8.10% 8.10%  
Total $ 300   300
Guaranteed Notes due 2043, $750 million, 5.25% ($17 million of discount; $6 million of debt issuance cost) | Issued by LYB International Finance B.V.:      
Long-term debt [Line Items]      
Face amount $ 750    
Stated interest rate (in percent) 5.25% 5.25%  
Unamortized discount $ 17    
Unamortized debt issuance cost 6    
Total 727   727
Guaranteed Notes due 2044, $1,000 million, 4.875% ($9 million of discount; $8 million of debt issuance cost) | Issued by LYB International Finance B.V.:      
Long-term debt [Line Items]      
Face amount $ 1,000    
Stated interest rate (in percent) 4.875% 4.875%  
Unamortized discount $ 9    
Unamortized debt issuance cost 8    
Total $ 983   983
Guaranteed Notes due 2026, €500 million, 0.875% | Issued by LYB International Finance II B.V.:      
Long-term debt [Line Items]      
Face amount | €   € 500  
Stated interest rate (in percent) 0.875% 0.875%  
Total $ 569   585
Guaranteed Notes due 2027, $1,000 million, 3.5% ($1 million of discount) | Issued by LYB International Finance II B.V.:      
Long-term debt [Line Items]      
Face amount $ 1,000    
Stated interest rate (in percent) 3.50% 3.50%  
Unamortized discount $ 1    
Total $ 589   590
Guaranteed Notes due 2031, €500 million, 1.625% ($3 million of discount; $2 million of debt issuance cost) | Issued by LYB International Finance II B.V.:      
Long-term debt [Line Items]      
Face amount | €   € 500  
Stated interest rate (in percent) 1.625% 1.625%  
Unamortized discount $ 3    
Unamortized debt issuance cost 2    
Total 560   577
Guaranteed Notes due 2030, $500 million, 3.375% | Issued by LYB International Finance III LLC:      
Long-term debt [Line Items]      
Face amount $ 500    
Stated interest rate (in percent) 3.375% 3.375%  
Total $ 144   142
Guaranteed Notes due 2030, $500 million, 2.25% ($2 million of discount; $2 million of debt issuance cost) | Issued by LYB International Finance III LLC:      
Long-term debt [Line Items]      
Face amount $ 500    
Stated interest rate (in percent) 2.25% 2.25%  
Unamortized discount $ 2    
Unamortized debt issuance cost 2    
Total 481   481
Guaranteed Notes due 2031, $500 million, 5.125% ($1 million of discount; $4 million of debt issuance cost) | Issued by LYB International Finance III LLC:      
Long-term debt [Line Items]      
Face amount $ 500    
Stated interest rate (in percent) 5.125% 5.125%  
Unamortized discount $ 1    
Unamortized debt issuance cost 4    
Total 495   495
Guaranteed Notes due 2033, $500 million, 5.625% ($4 million of debt issuance cost) | Issued by LYB International Finance III LLC:      
Long-term debt [Line Items]      
Face amount $ 500    
Stated interest rate (in percent) 5.625% 5.625%  
Unamortized debt issuance cost $ 4    
Total 496   496
Guaranteed Notes due 2034, $750 million, 5.5% ($5 million of discount, $6 million of debt issuance cost) | Issued by LYB International Finance III LLC:      
Long-term debt [Line Items]      
Face amount $ 750    
Stated interest rate (in percent) 5.50% 5.50%  
Unamortized discount $ 5    
Unamortized debt issuance cost 6    
Total 739   739
Guaranteed Notes due 2035, $500 million, 6.150% ($1 million of discount, $5 million of debt issuance cost | Issued by LYB International Finance III LLC:      
Long-term debt [Line Items]      
Face amount $ 500    
Stated interest rate (in percent) 6.15% 6.15%  
Unamortized discount $ 1    
Unamortized debt issuance cost 5    
Total 494   494
Guaranteed Notes due 2036, $1,000 million, 5.875% ($7 million of discount, $9 million of debt issuance cost | Issued by LYB International Finance III LLC:      
Long-term debt [Line Items]      
Face amount $ 1,000    
Stated interest rate (in percent) 5.875% 5.875%  
Unamortized discount $ 7    
Unamortized debt issuance cost 9    
Total 984   984
Guaranteed Notes due 2040, $750 million, 3.375% ($1 million of discount; $6 million of debt issuance cost) | Issued by LYB International Finance III LLC:      
Long-term debt [Line Items]      
Face amount $ 750    
Stated interest rate (in percent) 3.375% 3.375%  
Unamortized discount $ 1    
Unamortized debt issuance cost 6    
Total 743   743
Guaranteed Notes due 2049, $1,000 million, 4.2% ($13 million of discount; $10 million of debt issuance cost) | Issued by LYB International Finance III LLC:      
Long-term debt [Line Items]      
Face amount $ 1,000    
Stated interest rate (in percent) 4.20% 4.20%  
Unamortized discount $ 13    
Unamortized debt issuance cost 10    
Total 977   977
Guaranteed Notes due 2050, $1,000 million, 4.2% ($6 million of discount; $10 million of debt issuance cost) | Issued by LYB International Finance III LLC:      
Long-term debt [Line Items]      
Face amount $ 1,000    
Stated interest rate (in percent) 4.20% 4.20%  
Unamortized discount $ 6    
Unamortized debt issuance cost 10    
Total 970   971
Guaranteed Notes due 2051, $1,000 million, 3.625% ($2 million of discount; $9 million of debt issuance cost) | Issued by LYB International Finance III LLC:      
Long-term debt [Line Items]      
Face amount $ 1,000    
Stated interest rate (in percent) 3.625% 3.625%  
Unamortized discount $ 2    
Unamortized debt issuance cost 9    
Total 950   952
Guaranteed Notes due 2060, $500 million, 3.8% ($4 million of discount; $5 million of debt issuance cost) | Issued by LYB International Finance III LLC:      
Long-term debt [Line Items]      
Face amount $ 500    
Stated interest rate (in percent) 3.80% 3.80%  
Unamortized discount $ 4    
Unamortized debt issuance cost 5    
Total 485   487
Other      
Long-term debt [Line Items]      
Total $ 15   $ 14