v3.25.2
Shareholders' equity - Narrative (Details)
$ / shares in Units, $ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2025
USD ($)
$ / shares
shares
Jun. 30, 2024
USD ($)
Jun. 30, 2025
USD ($)
period
director
$ / shares
shares
Jun. 30, 2024
USD ($)
Dec. 31, 2024
$ / shares
shares
Class of Stock [Line Items]          
Common shares authorized (in shares) 300,000,000   300,000,000    
Common shares, par value (in dollars per share) | $ / shares $ 0.10   $ 0.10    
Dividends paid to common shareholders | $     $ 0.0 $ 0.0  
Dividends paid to preference shareholders | $     8.0 8.0  
Stock repurchase program, remaining authorized amount | $ $ 180.8   $ 180.8    
Director          
Class of Stock [Line Items]          
Common shares repurchased and retired (in shares)     500,000    
Shares acquired price (in dollars per share) | $ / shares     $ 14.00    
Preference shares          
Class of Stock [Line Items]          
Preference shares, shares authorized (in shares) 30,000,000   30,000,000    
Preference shares, par value (in dollars per share) | $ / shares $ 0.10   $ 0.10    
Series B preference shares          
Class of Stock [Line Items]          
Preference shares, shares authorized (in shares) 8,000,000   8,000,000   8,000,000
Preference shares, par value (in dollars per share) | $ / shares $ 0.10   $ 0.10   $ 0.10
Preference shares, shares outstanding (in shares) 8,000,000   8,000,000    
Dividend rate     8.00%    
Voting rights triggering event, number of dividend periods not paid | period     6    
Voting rights triggered, number of directors eligible to elect | director     2    
Dividend rate reset period     5 years    
Dividend rate basis spread on variable rate     7.298%    
Each five-year anniversary triggering event, redemption percentage     100.00%    
Rating agency triggering event, redemption percentage     102.00%    
Capital disqualification triggering event, redemption percentage     100.00%    
Tax triggering event, redemption percentage     100.00%    
Dividends paid to preference shareholders | $ $ 4.0 $ 4.0 $ 8.0 $ 8.0