Investments (Details 1) $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 30, 2015 USD ($) Number	Dec. 31, 2014 USD ($) Number
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less		$ 1,498,556	$ 746,584
Fixed maturity securities, Fair Value, More than 12 Months		182,049	388,536
Fixed maturity securities, Fair Value, Total		1,680,605	1,135,120
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less		43,491	14,482
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months		13,688	14,941
Fixed maturity securities, Gross Unrealized Losses, Total		$ 57,179	$ 29,423
Number of positions with a gross unrealized loss position, 12 Months or Less | Number		519	234
Number of position with a gross unrealized loss position, more than 12 months | Number		64	112
Number of position with a gross unrealized loss position, Total | Number		583	346
Fair value as a percentage of total fixed maturities and equity securities fair value, 12 Months or Less		20.90%	10.70%
Fair value as a percentage of total fixed maturities and equity securities fair value, more than 12 months		2.50%	5.50%
Fair value as a percentage of total fixed maturities and equity securities fair value, Total		23.40%	16.20%
Mortgage-backed securities [Member]
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less		$ 24,742	$ 2
Fixed maturity securities, Fair Value, More than 12 Months		1,616	39,809
Fixed maturity securities, Fair Value, Total		26,358	39,811
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less		891	0
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months		93	1,390
Fixed maturity securities, Gross Unrealized Losses, Total		984	1,390
Other [Member]
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less		223,729	10,317
Fixed maturity securities, Fair Value, More than 12 Months		1,899	117,615
Fixed maturity securities, Fair Value, Total		225,628	127,932
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less		3,399	34
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months		100	3,015
Fixed maturity securities, Gross Unrealized Losses, Total		3,499	3,049
Municipal bonds [Member]
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less		158,166	31,821
Fixed maturity securities, Fair Value, More than 12 Months		21,189	59,715
Fixed maturity securities, Fair Value, Total		179,355	91,536
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less		5,887	200
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months		5,522	4,228
Fixed maturity securities, Gross Unrealized Losses, Total		11,409	4,428
Foreign government bonds [Member]
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less		5,933	0
Fixed maturity securities, Fair Value, More than 12 Months		0	0
Fixed maturity securities, Fair Value, Total		5,933	0
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less		54	0
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months		0	0
Fixed maturity securities, Gross Unrealized Losses, Total		54	0
Corporate bonds [Member]
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less		542,329	213,612
Fixed maturity securities, Fair Value, More than 12 Months		40,187	76,099
Fixed maturity securities, Fair Value, Total		582,516	289,711
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less		24,073	6,883
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months		6,198	4,373
Fixed maturity securities, Gross Unrealized Losses, Total		30,271	11,256
Other mortgage-backed securities [Member]
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less		497,157	477,877
Fixed maturity securities, Fair Value, More than 12 Months		110,542	88,663
Fixed maturity securities, Fair Value, Total		607,699	566,540
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less		4,689	4,797
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months		916	1,095
Fixed maturity securities, Gross Unrealized Losses, Total		5,605	5,892
Total fixed maturity securities [Member]
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less		1,452,056	733,629
Fixed maturity securities, Fair Value, More than 12 Months		175,433	381,901
Fixed maturity securities, Fair Value, Total		1,627,489	1,115,530
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less		38,993	11,914
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months		12,829	14,101
Fixed maturity securities, Gross Unrealized Losses, Total		51,822	26,015
Equity securities [Member]
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less	[1]	46,500	12,955
Fixed maturity securities, Fair Value, More than 12 Months	[1]	6,616	6,635
Fixed maturity securities, Fair Value, Total	[1]	53,116	19,590
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less	[1]	4,498	2,568
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months	[1]	859	840
Fixed maturity securities, Gross Unrealized Losses, Total	[1]	$ 5,357	$ 3,408

[1] Includes nonredeemable (perpetual) preferred stocks, common stocks and closed-end funds.