Schedule IV - Reinsurance (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Schedule IV Reinsurance [Abstract]                    
Premiums earned, gross amount                 $ 107,587 $ 83,358
Premiums earned, ceded to other companies                 (9,589) (12,542)
Premiums earned, assumed from other companies                 126 528
Net premiums earned $ 27,289 $ 25,575 $ 23,306 $ 21,954 $ 20,512 $ 17,976 $ 16,968 $ 15,888 $ 98,124 $ 71,344
Premiums earned, percent of amount assumed to net                 0.10% 0.70%