SCHEDULE IV - FINANCIAL INFORMATION OF REGISTRANT REINSURANCE (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]                        
Gross Amount                 $ 398,303 $ 292,064 $ 192,326  
Ceded to Other Companies                 53,288 40,867 26,586  
Net premiums earned $ 95,517 $ 92,381 $ 83,249 $ 73,868 $ 69,261 $ 65,407 $ 61,615 $ 54,914 345,015 251,197 165,740  
Parent                        
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]                        
Gross Amount                 398,303 292,064 192,326 $ 115,830
Ceded to Other Companies                 53,288 40,867 26,586 5,349
Assumed from Other Companies                 0 0 0 0
Net premiums earned                 $ 345,015 $ 251,197 $ 165,740 $ 110,481
Percentage of Amount Assumed to Net                 0.00% 0.00% 0.00% 0.00%