Financial Instruments and Fair Value Measurements - Summary of derivative and non-derivative financial instruments outstanding measured at fair value on a recurring basis (Details) - Fair value, inputs, level 2 - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	$ 48	$ 285
Derivative liabilities	454	222
Prepaid expenses and other current assets \| Commodities \| Derivatives designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	3	14
Prepaid expenses and other current assets \| Commodities \| Derivatives not designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	6	18
Prepaid expenses and other current assets \| Foreign currency \| Derivatives designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	11	146
Prepaid expenses and other current assets \| Foreign currency \| Derivatives not designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1	16
Prepaid expenses and other current assets \| Interest rates \| Derivatives designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	18	16
Other assets \| Commodities \| Derivatives designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	9	7
Other assets \| Commodities \| Derivatives not designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	2
Other assets \| Foreign currency \| Derivatives designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	66
Accrued and other current liabilities \| Commodities \| Derivatives designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	20	14
Accrued and other current liabilities \| Commodities \| Derivatives not designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	35	11
Accrued and other current liabilities \| Foreign currency \| Derivatives designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	103	9
Accrued and other current liabilities \| Foreign currency \| Derivatives not designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	20	1
Accrued and other current liabilities \| Interest rates \| Derivatives designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	26	36
Other liabilities \| Commodities \| Derivatives designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	1	5
Other liabilities \| Foreign currency \| Derivatives designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	147	0
Other liabilities \| Interest rates \| Derivatives designated as hedges:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	$ 102	$ 146

LyondellBasell Industries N.V. 10-Q