Earnings per share (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure Of Earnings Per Share Explanatory [Abstract]

Earnings Per Share Explanatory [Text Block]

As expressed, earnings per share are detailed as follows:

Basic earnings per share	12/31/2017 ThUS$		12/31/2016 ThUS$		12/31/2015 ThUS$
Earnings (losses) attributable to owners of the parent		427,697		278,290		236,889

	12/31/2017 Units		12/31/2016 Units		12/31/2015 Units
Number of common shares in circulation		263,196,524		263,196,524		263,196,524

	12/31/2017		12/31/2016		12/31/2015
Basic earnings per share (US$ per share)		1.6250		1.05732		0.84