Investments (Details 4) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Net Investment Income [Line Items]
Total other invested assets	$ 74,301		$ 74,301		$ 33,622
Investment Income	(627)	$ 681	5,584	$ 5,362
Renewable energy LLCs
Net Investment Income [Line Items]
Total other invested assets	26,021		26,021		$ 25,119
Investment Income	(659)	$ 697	3,956	$ 4,737
Renewable energy bridge financing notes
Net Investment Income [Line Items]
Total other invested assets	30,078		30,078
Investment Income	984		2,483
Limited partnerships
Net Investment Income [Line Items]
Total other invested assets	13,702		13,702		$ 4,003
Investment Income	(1,038)	$ (105)	(1,112)	$ 127
Bank holding companies
Net Investment Income [Line Items]
Total other invested assets	4,500		4,500		$ 4,500
Investment Income	$ 86	86	$ 257	314
Other
Net Investment Income [Line Items]
Total other invested assets
Investment Income		$ 3		$ 184