Unaudited Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Unaudited Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income	$ 4,001	$ 7,780	$ 24,082	$ 19,741
Unrealized net gains (losses) on securities:
Unrealized net gains (losses) arising during the period	4,900	(13,192)	7,471	(13,299)
Less: reclassification adjustment for net gains (losses) included in net income	2,164	2,739	8,985	1,658
Change in unrealized gains (losses) on investments	2,736	(15,931)	(1,514)	(14,957)
Foreign currency translation adjustments	(145)	(429)	398	(1,102)
Other comprehensive income (loss)	2,591	(16,360)	(1,116)	(16,059)
Comprehensive income (loss)	$ 6,592	$ (8,580)	$ 22,966	$ 3,682