Investments, Net Realized and Unrealized Investment Gains (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Net realized and unrealized investment gains [Abstract]
Net realized gains	$ 913	$ 2,056	$ 2,617	$ 3,388
Net unrealized gains			10,407		$ 12,417
Debt Securities [Member]
Net realized and unrealized investment gains [Abstract]
Net realized gains	41	129	420	194
Net unrealized gains			1,285		3,078
Equity Securities [Member]
Net realized and unrealized investment gains [Abstract]
Net realized gains	$ 872	$ 1,927	2,197	$ 3,194
Net unrealized gains			$ 9,122		$ 9,339