XML 47 R37.htm IDEA: XBRL DOCUMENT v3.10.0.1
Fair Value (Details) - USD ($)
$ in Thousands
 9 Months Ended 12 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities $ 704,195    
Equity securities 12,511    
Total available-for-sale securities 704,195   $ 758,713
Other limited partnership investments:      
Contributions made to the funds 217 $ 330  
Distributions received from the funds 3,046 $ 7,986  
Fixed maturities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities     745,961
U.S. treasury      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 36,425   11,734
States & political subdivisions      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 256,865   259,264
Foreign government securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities     503
Corporate debt securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 277,669   346,523
Residential mortgage-backed securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 2,494   25,571
Commercial mortgage-backed securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 46,860   32,804
Collateralized debt obligations      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 65,294   58,034
Other debt securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 18,588   11,528
Nonredeemable preferred stock | Financial services sector      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale equity securities     11,659
Nonredeemable preferred stock | Utilities sector      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale equity securities     1,093
Fair value measurements on a non-recurring basis      
Fair value measurements on a non-recurring basis      
Assets measured at fair value on a non-recurring basis 0    
Fair value measurements on a non-recurring basis      
Liabilities measured at fair value on a non-recurring basis 0    
Fair value measurements on a recurring basis      
Fair value measurements on a recurring basis by asset class and level of input      
Total available-for-sale securities     758,713
Total 720,023   763,529
Fair value measurements on a recurring basis | Fixed maturities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 704,195   745,961
Fair value measurements on a recurring basis | U.S. treasury      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 36,425   11,734
Fair value measurements on a recurring basis | States & political subdivisions      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 256,865   259,264
Fair value measurements on a recurring basis | Foreign government securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities     503
Fair value measurements on a recurring basis | Corporate debt securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 277,669   346,523
Fair value measurements on a recurring basis | Residential mortgage-backed securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 2,494   25,571
Fair value measurements on a recurring basis | Commercial mortgage-backed securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 46,860   32,804
Fair value measurements on a recurring basis | Collateralized debt obligations      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 65,294   58,034
Fair value measurements on a recurring basis | Other debt securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 18,588   11,528
Fair value measurements on a recurring basis | Equity securities      
Fair value measurements on a recurring basis by asset class and level of input      
Equity securities 12,511    
Fair value measurements on a recurring basis | Nonredeemable preferred stock | Financial services sector      
Fair value measurements on a recurring basis by asset class and level of input      
Equity securities 12,511    
Available-for-sale equity securities     11,659
Fair value measurements on a recurring basis | Nonredeemable preferred stock | Utilities sector      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale equity securities     1,093
Fair value measurements on a recurring basis | Real estate      
Other limited partnership investments:      
Contributions made to the funds 0   0
Distributions received from the funds 1,200   500
Unfunded commitments $ 0   $ 0
Fair value measurements on a recurring basis | Real estate | Minimum      
Other limited partnership investments:      
Underlying assets, liquidation period from inception of fund (in years) 5 years   5 years
Fair value measurements on a recurring basis | Real estate | Maximum      
Other limited partnership investments:      
Underlying assets, liquidation period from inception of fund (in years) 10 years   10 years
Fair value measurements on a recurring basis | Level 1      
Fair value measurements on a recurring basis by asset class and level of input      
Total available-for-sale securities     $ 2,015
Total $ 1,981   2,015
Fair value measurements on a recurring basis | Level 1 | Fixed maturities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 0   0
Fair value measurements on a recurring basis | Level 1 | U.S. treasury      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 0   0
Fair value measurements on a recurring basis | Level 1 | States & political subdivisions      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 0   0
Fair value measurements on a recurring basis | Level 1 | Foreign government securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities     0
Fair value measurements on a recurring basis | Level 1 | Corporate debt securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 0   0
Fair value measurements on a recurring basis | Level 1 | Residential mortgage-backed securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 0   0
Fair value measurements on a recurring basis | Level 1 | Commercial mortgage-backed securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 0   0
Fair value measurements on a recurring basis | Level 1 | Collateralized debt obligations      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 0   0
Fair value measurements on a recurring basis | Level 1 | Other debt securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 0   0
Fair value measurements on a recurring basis | Level 1 | Equity securities      
Fair value measurements on a recurring basis by asset class and level of input      
Equity securities 1,981    
Fair value measurements on a recurring basis | Level 1 | Nonredeemable preferred stock | Financial services sector      
Fair value measurements on a recurring basis by asset class and level of input      
Equity securities 1,981    
Available-for-sale equity securities     2,015
Fair value measurements on a recurring basis | Level 1 | Nonredeemable preferred stock | Utilities sector      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale equity securities     0
Fair value measurements on a recurring basis | Level 2      
Fair value measurements on a recurring basis by asset class and level of input      
Total available-for-sale securities     746,619
Total 705,550   746,619
Fair value measurements on a recurring basis | Level 2 | Fixed maturities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 695,020   735,882
Fair value measurements on a recurring basis | Level 2 | U.S. treasury      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 36,425   11,734
Fair value measurements on a recurring basis | Level 2 | States & political subdivisions      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 256,865   259,264
Fair value measurements on a recurring basis | Level 2 | Foreign government securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities     503
Fair value measurements on a recurring basis | Level 2 | Corporate debt securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 269,399   338,644
Fair value measurements on a recurring basis | Level 2 | Residential mortgage-backed securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 2,494   25,571
Fair value measurements on a recurring basis | Level 2 | Commercial mortgage-backed securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 46,860   32,804
Fair value measurements on a recurring basis | Level 2 | Collateralized debt obligations      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 65,294   55,834
Fair value measurements on a recurring basis | Level 2 | Other debt securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 17,683   11,528
Fair value measurements on a recurring basis | Level 2 | Equity securities      
Fair value measurements on a recurring basis by asset class and level of input      
Equity securities 10,530    
Fair value measurements on a recurring basis | Level 2 | Nonredeemable preferred stock | Financial services sector      
Fair value measurements on a recurring basis by asset class and level of input      
Equity securities 10,530    
Available-for-sale equity securities     9,644
Fair value measurements on a recurring basis | Level 2 | Nonredeemable preferred stock | Utilities sector      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale equity securities     1,093
Fair value measurements on a recurring basis | Level 3      
Fair value measurements on a recurring basis by asset class and level of input      
Total available-for-sale securities     10,079
Total 9,175   10,079
Fair value measurements on a recurring basis | Level 3 | Fixed maturities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 9,175   10,079
Fair value measurements on a recurring basis | Level 3 | U.S. treasury      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 0   0
Fair value measurements on a recurring basis | Level 3 | States & political subdivisions      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 0   0
Fair value measurements on a recurring basis | Level 3 | Foreign government securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities     0
Fair value measurements on a recurring basis | Level 3 | Corporate debt securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 8,270   7,879
Fair value measurements on a recurring basis | Level 3 | Residential mortgage-backed securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 0   0
Fair value measurements on a recurring basis | Level 3 | Commercial mortgage-backed securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 0   0
Fair value measurements on a recurring basis | Level 3 | Collateralized debt obligations      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 0   2,200
Fair value measurements on a recurring basis | Level 3 | Other debt securities      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale debt securities 905   0
Fair value measurements on a recurring basis | Level 3 | Equity securities      
Fair value measurements on a recurring basis by asset class and level of input      
Equity securities 0    
Fair value measurements on a recurring basis | Level 3 | Nonredeemable preferred stock | Financial services sector      
Fair value measurements on a recurring basis by asset class and level of input      
Equity securities 0    
Available-for-sale equity securities     0
Fair value measurements on a recurring basis | Level 3 | Nonredeemable preferred stock | Utilities sector      
Fair value measurements on a recurring basis by asset class and level of input      
Available-for-sale equity securities     0
Fair value measurements on a recurring basis | Net Asset Value (NAV) | Real estate      
Fair value measurements on a recurring basis by asset class and level of input      
Other limited partnership investments $ 3,317   $ 4,816