Earnings per Share (Narratives) (Details)	12 Months Ended
Dec. 31, 2020
Notes to Consolidated Financial Statements [Abstract]
Description of instruments with potential future dilutive effect not included in calculation of diluted earnings per share	At December 31, 2020, 27 million options (at December 31, 2019 and 2018 – 17.5 million options and 5 million options, respectively), were excluded from the diluted weighted average number of ordinary shares calculation as their effect would have been anti dilutive

The description of instruments (including contingently issuable shares) that could potentially dilute basic earnings per share in the future, but were not included in the calculation of diluted earnings per share because they are antidilutive for the period(s) presented.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 33
-IssueDate 2020-01-01
-Paragraph 70
-Subparagraph c
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-URIDate 2020-01-01

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