Investments (Details 3) $ in Thousands	Jun. 30, 2016 USD ($) Holdings	Dec. 31, 2015 USD ($) Holdings
Fair value
Less than 12 months	$ 91,518	$ 244,279
12 months or longer	58,148	48,518
Total	149,666	292,797
Unrealized losses
Less than 12 months	809	2,882
12 months or longer	1,570	3,151
Total	$ 2,379	$ 6,033
No. of holdings | Holdings	303	407
Investment grade
Fair value
Less than 12 months	$ 42,174	$ 174,723
12 months or longer	47,584	38,369
Total	89,758	213,092
Unrealized losses
Less than 12 months	170	1,296
12 months or longer	1,069	1,256
Total	$ 1,239	$ 2,552
No. of holdings | Holdings	56	105
Non-investment grade
Fair value
Less than 12 months	$ 49,344	$ 56,824
12 months or longer	10,564	10,149
Total	59,908	66,973
Unrealized losses
Less than 12 months	639	1,453
12 months or longer	501	1,895
Total	$ 1,140	$ 3,348
No. of holdings | Holdings	247	301
Fixed maturities
Fair value
Less than 12 months	$ 91,518	$ 231,547
12 months or longer	58,148	48,518
Total	149,666	280,065
Unrealized losses
Less than 12 months	809	2,749
12 months or longer	1,570	3,151
Total	$ 2,379	$ 5,900
No. of holdings | Holdings	303	406
States & political subdivisions
Fair value
Less than 12 months		$ 5,867
12 months or longer		0
Total		5,867
Unrealized losses
Less than 12 months		7
12 months or longer		0
Total		$ 7
No. of holdings | Holdings		3
Corporate debt securities
Fair value
Less than 12 months	$ 65,341	$ 172,831
12 months or longer	21,953	19,086
Total	87,294	191,917
Unrealized losses
Less than 12 months	666	2,447
12 months or longer	554	1,965
Total	$ 1,220	$ 4,412
No. of holdings | Holdings	260	349
Residential mortgage-backed securities
Fair value
Less than 12 months	$ 5,051	$ 9,827
12 months or longer	2,599	936
Total	7,650	10,763
Unrealized losses
Less than 12 months	18	84
12 months or longer	121	46
Total	$ 139	$ 130
No. of holdings | Holdings	7	9
Commercial mortgage-backed securities
Fair value
Less than 12 months	$ 1,283	$ 13,081
12 months or longer	17,931	19,081
Total	19,214	32,162
Unrealized losses
Less than 12 months	7	68
12 months or longer	765	1,021
Total	$ 772	$ 1,089
No. of holdings | Holdings	18	24
Collateralized debt obligations
Fair value
Less than 12 months	$ 19,843	$ 27,981
12 months or longer	13,681	9,174
Total	33,524	37,155
Unrealized losses
Less than 12 months	118	103
12 months or longer	114	118
Total	$ 232	$ 221
No. of holdings | Holdings	17	19
Other debt securities
Fair value
Less than 12 months	$ 0	$ 1,960
12 months or longer	1,984	241
Total	1,984	2,201
Unrealized losses
Less than 12 months	0	40
12 months or longer	16	1
Total	$ 16	$ 41
No. of holdings | Holdings	1	2
Common stock
Fair value
Less than 12 months		$ 12,732
12 months or longer		0
Total		12,732
Unrealized losses
Less than 12 months		133
12 months or longer		0
Total		$ 133
No. of holdings | Holdings		1