Investments, Net Realized and Unrealized Investment Gains (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Net realized and unrealized investment gains [Abstract]
Net realized gains	$ 1,126	$ 659	$ 3,743	$ 4,047
Net unrealized gains			7,736		$ 12,417
Debt Securities [Member]
Net realized and unrealized investment gains [Abstract]
Net realized gains	48	221	469	415
Net unrealized gains			3,255		3,078
Equity Securities [Member]
Net realized and unrealized investment gains [Abstract]
Net realized gains	$ 1,078	$ 438	3,274	$ 3,632
Net unrealized gains			$ 4,481		$ 9,339