XML 143 R51.htm IDEA: XBRL DOCUMENT v3.8.0.1
Main items related to operating activities - Amortization, depreciation and impairment (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Main items related to operating activities      
Amortization, depreciation and impairment of tangible assets and mineral interests $ (16,103) $ (13,523) $ (17,720)
Tangible assets      
Main items related to operating activities      
Amortization, depreciation and impairment of tangible assets and mineral interests (14,782) (12,615) (15,727)
Mineral assets      
Main items related to operating activities      
Amortization, depreciation and impairment of tangible assets and mineral interests $ (1,321) $ (908) $ (1,993)