XML 138 R131.htm IDEA: XBRL DOCUMENT v3.8.0.1
Earnings/(loss) per ordinary share - Summary of earnings (loss) per ordinary shares (Detail) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Earnings Per Share [Abstract]      
Basic earnings/(loss) per share attributable to ordinary shareholders of Rio Tinto $ 8,762 $ 4,617 $ (866)
Diluted earnings/(loss) per share attributable to ordinary shareholders of Rio Tinto $ 8,762 $ 4,617 $ (866)
Basic earnings/(loss) per share attributable to ordinary shareholders of Rio Tinto, Weighted average number of shares 1,786.7 1,797.3 1,824.7
Diluted earnings/(loss) per share attributable to ordinary shareholders of Rio Tinto, Weighted average number of shares 1,799.5 1,808.6 1,824.7
Basic earnings/(loss) per share $ 490.4 $ 256.9 $ (47.5)
Diluted earnings/(loss) per share $ 486.9 $ 255.3 $ (47.5)