XML 66 R86.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Reserve for Loss and Loss Expense (Reconciliation of Claims Development to Liability) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Net outstanding liabilities $ 1,551,491 $ 1,498,134 $ 1,345,074  
Liability for Unpaid Claims and Claims Adjustment Expense, Net 3,392,713      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 544,162 537,388 585,855 $ 611,200
Short-duration Insurance Contracts, Liability for Unpaid Claims and Claims Adjustment Expense, Accumulated Unallocated Claim Adjustment Expense 130,288      
Liability for Claims and Claims Adjustment Expense 4,067,163 $ 3,893,868 $ 3,771,240 $ 3,691,719
General Liability [Member] | Standard Commercial Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 1,280,416      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 195,830      
General Liability [Member] | E&S Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 365,943      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 14,319      
Workers Compensation [Member] | Standard Commercial Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 850,505      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 206,414      
Commercial Automobile [Member] | Standard Commercial Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 596,686      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 14,352      
Business Owners' Policies [Member] | Standard Commercial Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 86,747      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 3,012      
Commercial Property [Member] | Standard Commercial Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 52,071      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 26,526      
Commercial Property [Member] | E&S Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 8,199      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 317      
Other Commercial [Member] | Standard Commercial Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 9,399      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 9,113      
Total Standard Commercial Lines [Member] | Standard Commercial Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 2,875,824      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 455,247      
Personal Automobile [Member] | Standard Personal Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 100,331      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 44,104      
Homeowners [Member] | Standard Personal Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 31,752      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 1,182      
Other Personal [Member] | Standard Personal Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 10,664      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 28,993      
Standard Personal Lines [Member] | Standard Personal Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 142,747      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 74,279      
Total E&S Lines [Member] | E&S Lines [Member]        
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]        
Liability for Unpaid Claims and Claims Adjustment Expense, Net 374,142      
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments $ 14,636