Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 28,945	$ 23,283	$ 29,717
Unrealized net gains (losses) on securities:
Unrealized holding net gains (losses) arising during the period	8,618	(12,639)	7,835
Less: reclassification adjustment for net gains included in net income	(13,491)	(277)	(5,084)
Change in unrealized gains (losses) on investments	(4,873)	(12,916)	2,751
Foreign currency translation adjustments	235	(1,456)	(1,011)
Other comprehensive income (loss)	(4,638)	(14,372)	1,740
Comprehensive income	$ 24,307	$ 8,911	$ 31,457