v3.26.3
Consolidated Statements of Changes in Shareholders’ Equity (Unaudited) - USD ($)
$ in Millions
Total
Common shares
Common shares held in treasury, at cost
Additional paid-in capital
Accumulated other comprehensive income/(loss), net of tax
Retained earnings
Balance - beginning of period at Dec. 31, 2024   $ 1.2 $ (105.5) $ 2,044.6 $ 4.5 $ 503.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Common shares repurchased and retired   (0.2)   (248.0)    
Retirement of treasury shares     105.5      
Share compensation expense       5.3    
Shares withheld for employee taxes on restricted share unit vesting       (0.2)    
Unrealized gains/(losses) arising during the period, net of reclassification adjustment $ 35.6       35.6  
Net income 107.7         107.7
Dividends on common shares           (38.0)
Balance - end of period at Sep. 30, 2025 2,416.1 1.0 0.0 1,801.7 40.1 573.3
Balance - beginning of period at Jun. 30, 2025   1.0 0.0 1,831.2 32.7 458.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Common shares repurchased and retired   0.0   (31.9)    
Retirement of treasury shares     0.0      
Share compensation expense       2.4    
Shares withheld for employee taxes on restricted share unit vesting       0.0    
Unrealized gains/(losses) arising during the period, net of reclassification adjustment 7.4       7.4  
Net income           130.5
Dividends on common shares           (15.7)
Balance - end of period at Sep. 30, 2025 2,416.1 1.0 0.0 1,801.7 40.1 573.3
Balance - beginning of period at Dec. 31, 2025   1.0 0.0 1,685.6 37.1 675.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Common shares repurchased and retired   (0.2)   (362.3)    
Retirement of treasury shares     0.0      
Share compensation expense       8.8    
Shares withheld for employee taxes on restricted share unit vesting       (1.7)    
Unrealized gains/(losses) arising during the period, net of reclassification adjustment (78.7)       (78.7)  
Net income 214.1         214.1
Dividends on common shares           (38.4)
Balance - end of period at Sep. 30, 2026 2,141.2 0.8 0.0 1,330.4 (41.6) 851.6
Balance - beginning of period at Jun. 30, 2026   0.8 0.0 1,409.9 7.3 802.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Common shares repurchased and retired   0.0   (83.0)    
Retirement of treasury shares     0.0      
Share compensation expense       3.6    
Shares withheld for employee taxes on restricted share unit vesting       (0.1)    
Unrealized gains/(losses) arising during the period, net of reclassification adjustment (48.9)       (48.9)  
Net income           61.7
Dividends on common shares           (12.6)
Balance - end of period at Sep. 30, 2026 $ 2,141.2 $ 0.8 $ 0.0 $ 1,330.4 $ (41.6) $ 851.6