XML 113 R84.htm IDEA: XBRL DOCUMENT v3.24.0.1
Short-Duration Insurance Contracts - Incurred and Paid Claims by Accident Year on a Net Basis (Details)
$ in Millions
Dec. 31, 2023
USD ($)
claim
Dec. 31, 2022
USD ($)
Dec. 31, 2021
USD ($)
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Homeowners                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 1,398.3                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 1,324.9                  
Outstanding prior to 2013 0.0                  
Prior years paid 0.0                  
Liabilities for claims and claim adjustment expenses, net of reinsurance 73.4                  
Homeowners | 2014                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 106.4 $ 106.4 $ 106.4 $ 106.4 $ 106.6 $ 106.6 $ 106.8 $ 109.1 $ 113.5 $ 111.6
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 19,777                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 106.4 106.4 106.4 106.4 106.4 106.3 106.1 105.7 103.0 83.3
Homeowners | 2015                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 114.9 114.9 114.9 114.9 115.1 114.1 114.4 115.1 111.7  
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 19,745                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 114.9 114.7 114.7 114.9 114.6 113.3 111.9 109.3 90.7  
Homeowners | 2016                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 118.1 118.1 117.9 117.9 117.9 117.0 118.6 115.9    
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 19,662                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 118.1 118.0 117.8 117.7 117.5 115.1 113.2 95.8    
Homeowners | 2017                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 131.3 130.8 130.8 130.7 132.7 129.8 126.3      
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.3                  
Cumulative Number of Reported Claims | claim 19,741                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 131.2 130.7 130.5 130.0 129.8 128.5 106.8      
Homeowners | 2018                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 156.0 157.2 158.1 158.9 157.4 166.8        
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.5                  
Cumulative Number of Reported Claims | claim 20,296                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 156.2 157.2 157.4 157.0 152.4 130.5        
Homeowners | 2019                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 131.1 130.9 132.1 129.9 130.4          
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.3                  
Cumulative Number of Reported Claims | claim 18,114                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 130.4 130.0 129.1 126.2 103.8          
Homeowners | 2020                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 146.9 145.4 151.9 155.7            
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.7                  
Cumulative Number of Reported Claims | claim 18,906                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 145.6 144.0 138.7 106.8            
Homeowners | 2021                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 154.3 150.7 150.2              
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 1.9                  
Cumulative Number of Reported Claims | claim 18,056                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 151.0 146.3 114.9              
Homeowners | 2022                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 156.2 162.2                
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 8.4                  
Cumulative Number of Reported Claims | claim 15,036                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 144.8 108.3                
Homeowners | 2023                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 183.1                  
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 38.8                  
Cumulative Number of Reported Claims | claim 14,655                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 126.3                  
Auto liability                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 1,731.0                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 1,531.2                  
Outstanding prior to 2013 1.1                  
Prior years paid 0.0                  
Liabilities for claims and claim adjustment expenses, net of reinsurance 200.9                  
Auto liability | 2014                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 160.1 160.0 159.4 159.3 159.4 159.8 159.9 158.5 157.2 155.1
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 64,648                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 160.0 160.0 158.8 158.6 157.6 155.8 149.1 139.5 117.5 61.3
Auto liability | 2015                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 178.9 178.8 178.9 179.2 178.7 178.3 177.0 172.6 165.5  
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 68,626                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 178.6 178.3 177.7 176.7 174.5 170.1 158.0 134.5 70.8  
Auto liability | 2016                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 189.5 189.6 189.2 188.1 186.6 184.6 184.4 180.4    
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.1                  
Cumulative Number of Reported Claims | claim 70,684                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 189.4 189.0 188.1 184.5 177.8 166.8 140.9 73.1    
Auto liability | 2017                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 192.5 192.9 191.7 189.1 188.6 188.8 188.0      
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.3                  
Cumulative Number of Reported Claims | claim 68,371                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 191.8 190.8 185.8 179.8 166.6 139.5 70.7      
Auto liability | 2018                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 192.3 192.0 189.8 192.9 195.3 200.3        
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 1.1                  
Cumulative Number of Reported Claims | claim 35,394                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 190.6 188.0 180.7 168.6 141.5 77.5        
Auto liability | 2019                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 181.2 181.5 176.7 180.1 181.1          
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 3.0                  
Cumulative Number of Reported Claims | claim 61,879                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 176.2 170.9 155.5 129.1 69.7          
Auto liability | 2020                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 137.3 136.3 134.9 137.0            
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 4.7                  
Cumulative Number of Reported Claims | claim 46,934                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 129.2 118.2 94.0 51.5            
Auto liability | 2021                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 156.7 157.8 142.2              
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 11.5                  
Cumulative Number of Reported Claims | claim 45,005                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 136.5 112.5 52.9              
Auto liability | 2022                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 166.1 165.6                
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 26.9                  
Cumulative Number of Reported Claims | claim 46,104                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 116.7 55.8                
Auto liability | 2023                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 176.4                  
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 70.0                  
Cumulative Number of Reported Claims | claim 42,198                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 62.2                  
Auto physical damage                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 1,081.2                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 1,070.2                  
Outstanding prior to 2013 0.0                  
Prior years paid 0.0                  
Liabilities for claims and claim adjustment expenses, net of reinsurance 11.0                  
Auto physical damage | 2014                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 95.2 95.2 95.2 95.2 95.2 95.2 95.2 95.4 95.6 95.6
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 68,139                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 95.2 95.2 95.2 95.2 95.2 95.3 95.3 95.3 95.4 88.9
Auto physical damage | 2015                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 97.6 97.6 97.6 97.6 97.6 97.5 97.6 98.0 99.3  
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 70,685                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 97.6 97.6 97.6 97.6 97.6 97.6 97.7 97.9 92.1  
Auto physical damage | 2016                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 109.6 109.5 109.5 109.6 109.6 109.3 109.5 112.4    
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 74,209                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 109.5 109.5 109.6 109.6 109.6 109.5 109.7 106.5    
Auto physical damage | 2017                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 110.6 110.6 110.5 110.6 110.5 111.8 115.5      
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 73,998                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 110.6 110.6 110.6 110.6 110.7 110.8 105.2      
Auto physical damage | 2018                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 108.3 108.2 108.3 108.3 108.9 109.0        
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 72,833                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 108.2 108.2 108.3 108.3 109.1 103.6        
Auto physical damage | 2019                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 109.9 110.0 110.0 110.5 111.6          
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ (0.1)                  
Cumulative Number of Reported Claims | claim 73,128                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 110.1 110.1 110.1 110.7 106.2          
Auto physical damage | 2020                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 87.0 87.1 86.9 87.0            
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ (0.3)                  
Cumulative Number of Reported Claims | claim 62,044                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 87.3 87.4 87.6 84.1            
Auto physical damage | 2021                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 105.1 105.7 105.0              
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ (0.4)                  
Cumulative Number of Reported Claims | claim 58,080                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 105.4 105.8 97.3              
Auto physical damage | 2022                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 125.5 125.7                
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.9                  
Cumulative Number of Reported Claims | claim 59,353                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 124.3 114.6                
Auto physical damage | 2023                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 132.4                  
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ (6.0)                  
Cumulative Number of Reported Claims | claim 58,167                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 122.0                  
Specialty health                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 185.0                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 174.1                  
Outstanding prior to 2013 0.0                  
Prior years paid 0.0                  
Liabilities for claims and claim adjustment expenses, net of reinsurance 10.9                  
Specialty health | 2014                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 56.0 56.0 56.0 56.0 56.0 56.0 56.0 55.9 56.3 59.6
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 337,987                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 56.0 56.0 56.0 56.0 56.0 55.9 55.7 55.4 54.9 43.4
Specialty health | 2015                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 30.4 30.4 30.4 30.4 30.3 30.3 30.3 30.9 33.3  
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 183,433                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 30.4 30.4 30.4 30.4 30.3 30.3 30.3 30.4 24.9  
Specialty health | 2016                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 11.1 11.1 11.1 11.1 11.1 11.1 11.2 12.5    
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 67,274                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 11.1 11.1 11.1 11.1 11.1 11.1 11.0 5.5    
Specialty health | 2017                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 9.6 9.6 9.6 9.6 9.6 9.7 10.6      
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 63,492                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 9.6 9.6 9.6 9.6 9.6 9.4 7.3      
Specialty health | 2018                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 12.6 12.6 12.7 13.0 13.2 12.9        
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 95,218                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 12.6 12.6 12.6 12.5 12.1 8.8        
Specialty health | 2019                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 9.5 9.5 9.6 9.5 10.6          
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 72,754                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 9.5 9.5 9.5 9.3 7.5          
Specialty health | 2020                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 5.7 5.7 5.8 6.8            
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 43,609                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 5.7 5.7 5.6 4.2            
Specialty health | 2021                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 16.1 17.7 22.8              
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 2.4                  
Cumulative Number of Reported Claims | claim 72,407                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 13.7 12.9 2.9              
Specialty health | 2022                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 18.0 22.6                
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 1.3                  
Cumulative Number of Reported Claims | claim 120,965                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 16.7 10.5                
Specialty health | 2023                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 16.0                  
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 7.1                  
Cumulative Number of Reported Claims | claim 79,654                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 8.8                  
Group disability                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 280.8                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 206.6                  
Outstanding prior to 2013 9.0                  
Prior years paid 100.3                  
Liabilities for claims and claim adjustment expenses, net of reinsurance 83.2                  
Effect of discounting (14.0)                  
Discounted net reserves 69.2                  
Group disability | 2014                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 14.5 14.6 14.3 14.7 14.5 14.3 14.4 14.8 13.3 16.3
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 2,863                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 12.9 12.7 12.4 12.1 11.7 11.1 10.6 9.9 8.5 $ 3.7
Group disability | 2015                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 14.5 14.7 15.2 15.2 14.6 14.7 16.6 19.2 25.3  
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.0                  
Cumulative Number of Reported Claims | claim 3,347                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 19.1 18.9 18.6 18.1 17.6 17.2 16.6 14.0 $ 6.8  
Group disability | 2016                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 28.1 28.1 26.8 26.3 26.0 27.4 28.6 28.5    
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.7                  
Cumulative Number of Reported Claims | claim 3,618                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 22.9 22.4 21.8 21.1 20.3 19.3 16.4 $ 8.3    
Group disability | 2017                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 23.1 24.0 23.3 22.4 22.9 26.0 29.9      
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.1                  
Cumulative Number of Reported Claims | claim 3,904                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 19.7 19.4 18.9 18.3 17.9 16.1 $ 8.5      
Group disability | 2018                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 23.6 23.3 22.7 23.2 26.6 29.8        
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.3                  
Cumulative Number of Reported Claims | claim 4,171                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 20.1 19.6 18.9 18.0 16.1 $ 8.4        
Group disability | 2019                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 30.2 29.9 30.2 33.5 34.5          
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.5                  
Cumulative Number of Reported Claims | claim 4,549                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 25.2 24.7 24.3 22.8 $ 11.8          
Group disability | 2020                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 33.2 34.1 34.3 36.7            
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 0.6                  
Cumulative Number of Reported Claims | claim 4,343                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 26.4 25.5 22.7 $ 12.4            
Group disability | 2021                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 41.3 41.3 37.8              
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 2.0                  
Cumulative Number of Reported Claims | claim 5,109                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 26.7 24.0 $ 11.8              
Group disability | 2022                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 32.0 39.2                
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ (0.5)                  
Cumulative Number of Reported Claims | claim 4,349                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 21.4 $ 11.7                
Group disability | 2023                    
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]                    
Incurred Claims and Allocated Claim Adjustment Expense, Net of Reinsurance 40.3                  
Total of Incurred- But-Not-Reported Liabilities Plus Expected Development on Reported Claims $ 13.2                  
Cumulative Number of Reported Claims | claim 3,510                  
Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net of Reinsurance $ 12.2