XML 211 R191.htm IDEA: XBRL DOCUMENT v3.21.1
Common Shareholders' Equity (Details 1)
 12 Months Ended
Dec. 02, 2020
$ / shares
Apr. 15, 2020
$ / shares
Dec. 31, 2020
$ / shares
Dec. 31, 2019
$ / shares
Dec. 31, 2018
$ / shares
Dec. 31, 2017
$ / shares
Dec. 31, 2016
Dec. 04, 2019
$ / shares
Apr. 17, 2019
$ / shares
Dec. 05, 2018
$ / shares
Apr. 11, 2018
$ / shares
Dec. 06, 2017
$ / shares
Interim dividend                        
Disclosure of Common Shareholders' Equity [Line Items]                        
Dividend paid date Dec. 30, 2020   Dec. 30, 2020 Dec. 26, 2019 Jan. 04, 2019 Jan. 05, 2018            
Dividend per Share | (per share) $ 56   $ 56.0000 $ 75.0000 $ 140.0000 $ 70.0000   $ 75   $ 140   $ 70
Year of dividend     2020 2019 2018 2017            
Final dividend                        
Disclosure of Common Shareholders' Equity [Line Items]                        
Dividend paid date   Apr. 24, 2020   Apr. 24, 2020 Apr. 29, 2019 Apr. 26, 2018            
Dividend per Share | (per share)   $ 179.95079   $ 179.97079 $ 358.33030 $ 108.88833     $ 35,833,030   $ 108.88833  
Year of dividend         2018 2017 2019