Debt, Formation of LYB International Finance B.V., LYB International Finance II B.V. and LYB International Finance III, LLC (Details)	3 Months Ended
	Mar. 31, 2020
Formation of direct, 100% owned finance subsidiary [Abstract]
LYB International Finance B.V., LYB International Finance II B.V. and LYB International Finance III, LLC business activities and description	LYB International Finance B.V., LYB International Finance II B.V. and LYB International Finance III, LLC are direct, 100% owned finance subsidiaries of LyondellBasell Industries N.V., as defined in Rule 3-10(b) of Regulation S-X. Any debt securities issued by LYB International Finance B.V., LYB International Finance II B.V. and LYB International Finance III, LLC will be fully and unconditionally guaranteed by LyondellBasell Industries N.V.