Investments Components of Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Components of net investment income
Interest on fixed maturity securities	$ 9,515	$ 9,260	$ 18,349	$ 18,529
Dividends on equity securities	662	753	1,322	1,560
Equity in earnings of other invested assets	171	257	408	416
Interest on other assets	21	16	43	32
Interest on cash and cash equivalents		32		43
Total investment income	10,369	10,318	20,122	20,580
Investment expenses	654	677	1,312	1,312
Net investment income	$ 9,715	$ 9,641	$ 18,810	$ 19,268