Investments Net Investment Income by Major Category (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net Investment Income [Line Items]
Net investment income	$ 9,212	$ 6,795	$ 3,871
Investment expenses	(267)	(312)	(206)
Investment Income, Net	8,945	6,483	3,665
Debt Securities [Member]
Net Investment Income [Line Items]
Net investment income	8,092	5,866	3,512
Equity Securities [Member]
Net Investment Income [Line Items]
Net investment income	859	734	280
Cash, Cash Equivalents And Short-Term Investments [Member]
Net Investment Income [Line Items]
Net investment income	25	9
Cash and Cash Equivalents [Member]
Net Investment Income [Line Items]
Net investment income			31
Partnership Interest [Member]
Net Investment Income [Line Items]
Net investment income	222	166	48
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Net Investment Income [Line Items]
Net investment income	$ 14	$ 20	$ 0