XML 40 R33.htm IDEA: XBRL DOCUMENT v3.21.2
Property, plant and equipment - Narrative (Details)
6 Months Ended
Jun. 30, 2021
USD ($)
Disclosure of detailed information about property, plant and equipment [line items]  
Right of use Assets $ 3,618,000,000
Gross depreciation of right of use (RoU) assets 636,000,000
Additions to RoU assets 167,000,000
Exploration and development assets [member]  
Disclosure of detailed information about property, plant and equipment [line items]  
Gross depreciation of right of use (RoU) assets $ 158,000,000