XML 136 R87.htm IDEA: XBRL DOCUMENT v3.20.1
Reserves for Losses and Adjustment Expenses Short-duration insurance contracts - Reconciliation of Claims Development (Details) - USD ($)
$ in Millions
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for claims and claim adjustment expenses, net of reinsurance $ 4,815.5      
Reinsurance recoverable on unpaid losses 2,319.8      
Unallocated claims incurred 44.0      
Other (0.1)      
Liability for unpaid claims and claim adjustment expense, aggregate reconciling items (183.5)      
Losses and loss adjustment expenses 6,951.8 $ 7,074.2 $ 6,749.5 $ 5,319.9
Property Insurance        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for claims and claim adjustment expenses, net of reinsurance 190.7      
Casualty Insurance        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for claims and claim adjustment expenses, net of reinsurance 669.2      
Marine, Aviation and Energy Insurance        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for claims and claim adjustment expenses, net of reinsurance 591.5      
Financial and Professional Insurance        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for claims and claim adjustment expenses, net of reinsurance 657.4      
Insurance lines        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for claims and claim adjustment expenses, net of reinsurance 2,108.8      
Reinsurance recoverable on unpaid losses 1,772.8      
Property Catastrophe and Other Property Reinsurance        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for claims and claim adjustment expenses, net of reinsurance 528.6      
Casualty Reinsurance        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for claims and claim adjustment expenses, net of reinsurance 1,602.2      
Specialty Reinsurance        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for claims and claim adjustment expenses, net of reinsurance 575.9      
Reinsurance lines        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for claims and claim adjustment expenses, net of reinsurance 2,706.7      
Reinsurance recoverable on unpaid losses 547.0      
Insurance lines other than short-duration        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Other reinsurance balances recoverable (227.4)      
Losses and loss adjustment expenses $ 0.0