Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fixed maturities [Abstract]
Total fixed maturities	$ 508,802	$ 491,904
Equity securities [Abstract]
Total equity securities	135,514	119,945
Recurring [Member]
Fixed maturities [Abstract]
Agency collateralized mortgage obligations	7,446	6,171
Agency mortgage-backed securities	10,693	4,770
Asset-backed securities	48,241	45,183
Bank loans	9,144	10,349
Certificates of deposit	3,119	3,117
Collateralized mortgage obligations	6,119	9,104
Corporate securities	177,294	137,932
Options embedded in convertible securities	5,015	4,751
Mortgage-backed securities	24,019	24,571
Municipal obligations	128,882	129,335
Non-U.S. government obligations	21,428	24,681
U.S. government obligations	67,402	91,940
Total fixed maturities	508,802	491,904
Equity securities [Abstract]
Consumer	41,624	32,576
Energy	11,025	12,842
Financial	35,109	31,186
Industrial	24,147	21,145
Technology	9,518	8,858
Mutual fund	7,311	6,995
Other	6,780	6,343
Total equity securities	135,514	119,945
Short-term	1,500	1,500
Cash equivalents	50,719	59,683
Total fair value	696,535	673,032
Recurring [Member] | Level 1 [Member]
Fixed maturities [Abstract]
Agency collateralized mortgage obligations	0	0
Agency mortgage-backed securities	0	0
Asset-backed securities	0	0
Bank loans	0	0
Certificates of deposit	3,119	3,117
Collateralized mortgage obligations	0	0
Corporate securities	20,025	0
Options embedded in convertible securities	0	0
Mortgage-backed securities	0	0
Municipal obligations	0	0
Non-U.S. government obligations	0	0
U.S. government obligations	0	0
Total fixed maturities	23,144	3,117
Equity securities [Abstract]
Consumer	41,624	32,576
Energy	11,025	12,842
Financial	35,109	30,943
Industrial	23,139	20,262
Technology	9,518	8,858
Mutual fund	3,646	0
Other	6,780	6,343
Total equity securities	130,841	111,824
Short-term	1,500	1,500
Cash equivalents	0	0
Total fair value	155,485	116,441
Recurring [Member] | Level 2 [Member]
Fixed maturities [Abstract]
Agency collateralized mortgage obligations	7,446	6,171
Agency mortgage-backed securities	10,693	4,770
Asset-backed securities	40,980	37,919
Bank loans	0	0
Certificates of deposit	0	0
Collateralized mortgage obligations	5,225	6,409
Corporate securities	156,477	135,794
Options embedded in convertible securities	5,015	4,751
Mortgage-backed securities	21,772	22,206
Municipal obligations	128,769	129,190
Non-U.S. government obligations	21,428	24,419
U.S. government obligations	67,402	91,940
Total fixed maturities	465,207	463,569
Equity securities [Abstract]
Consumer	0	0
Energy	0	0
Financial	0	243
Industrial	1,008	883
Technology	0	0
Mutual fund	3,665	6,995
Other	0	0
Total equity securities	4,673	8,121
Short-term	0	0
Cash equivalents	50,719	59,683
Total fair value	520,599	531,373
Recurring [Member] | Level 3 [Member]
Fixed maturities [Abstract]
Agency collateralized mortgage obligations	0	0
Agency mortgage-backed securities	0	0
Asset-backed securities	7,261	7,264
Bank loans	9,144	10,349
Certificates of deposit	0	0
Collateralized mortgage obligations	894	2,695
Corporate securities	792	2,138
Options embedded in convertible securities	0	0
Mortgage-backed securities	2,247	2,365
Municipal obligations	113	145
Non-U.S. government obligations	0	262
U.S. government obligations	0	0
Total fixed maturities	20,451	25,218
Equity securities [Abstract]
Consumer	0	0
Energy	0	0
Financial	0	0
Industrial	0	0
Technology	0	0
Mutual fund	0	0
Other	0	0
Total equity securities	0	0
Short-term	0	0
Cash equivalents	0	0
Total fair value	$ 20,451	$ 25,218