v3.22.2.2
Accumulated Other Comprehensive Income - Components of Accumulated Other Comprehensive Income, Net of Tax (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Beginning balance     $ 5,464.1  
Change in accumulated other comprehensive income (loss) before reclassifications $ (272.5) $ (67.7) (965.9) $ (164.5)
Amounts reclassified from accumulated other comprehensive income (loss) 9.8 (620.4) 31.0 (629.4)
Total other comprehensive loss (262.7) (688.1) (934.9) (793.9)
Ending balance 4,098.9   4,098.9  
Accumulated Other Comprehensive Income (Loss)        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Beginning balance (822.2) 604.0 (150.0) 709.8
Total other comprehensive loss (262.7) (688.1) (934.9) (793.9)
Ending balance (1,084.9) (84.1) (1,084.9) (84.1)
Foreign currency translation adjustment        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Beginning balance (367.5) (274.8) (326.9) (295.6)
Change in accumulated other comprehensive income (loss) before reclassifications (51.4) (23.4) (92.0) (2.6)
Amounts reclassified from accumulated other comprehensive income (loss) 0.0 (0.3) 0.0 (0.3)
Total other comprehensive loss (51.4) (23.7) (92.0) (2.9)
Ending balance (418.9) (298.5) (418.9) (298.5)
Net unrealized gains (losses) on securities        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Beginning balance (370.1) 974.5 256.6 1,097.6
Change in accumulated other comprehensive income (loss) before reclassifications (221.5) (44.6) (874.3) (162.5)
Amounts reclassified from accumulated other comprehensive income (loss) 12.2 (618.5) 38.3 (623.7)
Total other comprehensive loss (209.3) (663.1) (836.0) (786.2)
Ending balance (579.4) 311.4 (579.4) 311.4
Net unrealized gains on derivative transactions        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Beginning balance 11.1 13.5 12.4 14.7
Change in accumulated other comprehensive income (loss) before reclassifications 0.0 0.0 0.0 0.0
Amounts reclassified from accumulated other comprehensive income (loss) (0.6) (0.6) (1.9) (1.8)
Total other comprehensive loss (0.6) (0.6) (1.9) (1.8)
Ending balance 10.5 12.9 10.5 12.9
Unamortized net losses on Pension Plans        
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]        
Beginning balance (95.7) (109.2) (92.1) (106.9)
Change in accumulated other comprehensive income (loss) before reclassifications 0.4 0.3 0.4 0.6
Amounts reclassified from accumulated other comprehensive income (loss) (1.8) (1.0) (5.4) (3.6)
Total other comprehensive loss (1.4) (0.7) (5.0) (3.0)
Ending balance $ (97.1) $ (109.9) $ (97.1) $ (109.9)