XML 98 R76.htm IDEA: XBRL DOCUMENT v3.20.2
Common shareholder's equity, mezzanine equity, and non controlling interests - Mezzanine equity (Details) - USD ($)
$ / shares in Units, $ in Millions
9 Months Ended
Sep. 30, 2020
Dec. 31, 2019
Nov. 05, 2018
Mezzanine equity      
Preference shares authorized / designated ( in shares) 100,000,000    
Preference shares par value (in dollars per share) $ 0.01    
Carrying value of preference shares $ 197.5 $ 223.0  
Series B preference shares      
Mezzanine equity      
Preference shares authorized / designated ( in shares)     15,000,000
Preference shares par value (in dollars per share)     $ 0.01
Preferential rights, aggregate gross proceeds from the issuance of senior or pari passu shares $ 100.0    
Series B preference shares | Sirius group private placement | Preference share investors      
Mezzanine equity      
Share subscriptions (in shares)     11,901,670