Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fixed maturities [Abstract]
Total fixed maturities	$ 491,904	$ 437,184
Equity securities [Abstract]
Total equity securities	119,945	145,498
Recurring [Member]
Fixed maturities [Abstract]
Agency collateralized mortgage obligations	6,171	0
Agency mortgage-backed securities	4,770	3,157
Asset-backed securities	45,183	44,309
Bank loans	10,349	5,060
Certificates of deposit	3,117	3,230
Collateralized mortgage obligations	9,104	9,257
Corporate securities	137,932	108,116
Options embedded in convertible securities	4,751	2,395
Mortgage-backed securities	24,571	23,892
Municipal obligations	129,335	110,578
Non-U.S. government obligations	24,681	23,945
U.S. government obligations	91,940	103,245
Total fixed maturities	491,904	437,184
Equity securities [Abstract]
Consumer	32,576	46,541
Energy	12,842	8,635
Financial	31,186	35,686
Industrial	21,145	24,841
Technology	8,858	11,596
Mutual fund	6,995	9,983
Other	6,343	8,216
Total equity securities	119,945	145,498
Short term	1,500	2,220
Cash equivalents	59,683	69,517
Total fair value	673,032	654,419
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	3,117	0
Collateralized mortgage obligations	0	0
Corporate securities	0	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	3,117	0
Equity securities [Abstract]
Consumer	32,576	46,541
Energy	12,842	8,635
Financial	30,943	34,431
Industrial	20,262	24,274
Technology	8,858	11,596
Mutual fund	0	0
Other	6,343	8,216
Total equity securities	111,824	133,693
Short term	1,500	2,220
Cash equivalents	0	0
Total fair value	116,441	135,913
Recurring [Member] | Level 2 [Member]
Fixed maturities [Abstract]
Agency collateralized mortgage obligations	6,171	0
Agency mortgage-backed securities	4,770	3,157
Asset-backed securities	37,919	37,235
Bank loans	0	0
Certificates of deposit	0	3,230
Collateralized mortgage obligations	6,409	9,257
Corporate securities	135,794	105,108
Options embedded in convertible securities	4,751	2,395
Mortgage-backed securities	22,206	22,523
Municipal obligations	129,190	110,578
Non-U.S. government obligations	24,419	23,663
U.S. government obligations	91,940	103,245
Total fixed maturities	463,569	420,391
Equity securities [Abstract]
Consumer	0	0
Energy	0	0
Financial	243	1,255
Industrial	883	567
Technology	0	0
Mutual fund	6,995	9,983
Other	0	0
Total equity securities	8,121	11,805
Short term	0	0
Cash equivalents	59,683	69,517
Total fair value	531,373	501,713
Recurring [Member] | Level 3 [Member]
Fixed maturities [Abstract]
Agency collateralized mortgage obligations	0	0
Agency mortgage-backed securities	0	0
Asset-backed securities	7,264	7,074
Bank loans	10,349	5,060
Certificates of deposit	0	0
Collateralized mortgage obligations	2,695	0
Corporate securities	2,138	3,008
Options embedded in convertible securities	0	0
Mortgage-backed securities	2,365	1,369
Municipal obligations	145	0
Non-U.S. government obligations	262	282
U.S. government obligations	0	0
Total fixed maturities	25,218	16,793
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	$ 25,218	$ 16,793