Unaudited Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Unaudited Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income	$ 7,780	$ 5,770	$ 19,741	$ 21,471
Unrealized net gains (losses) on securities:
Unrealized net gains (losses) arising during the period	(13,192)	(3,472)	(13,299)	9,358
Less: reclassification adjustment for net gains (losses) included in net income	2,739	1,118	1,658	3,648
Change in unrealized gains on investments	(15,931)	(4,590)	(14,957)	5,710
Foreign currency translation adjustments	(429)	(705)	(1,102)	(835)
Other comprehensive income (loss)	(16,360)	(5,295)	(16,059)	4,875
Comprehensive income (loss)	$ (8,580)	$ 475	$ 3,682	$ 26,346