Unaudited Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Unaudited Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 5,718	$ 9,340	$ 11,961	$ 15,701
Unrealized net gains (losses) on securities:
Unrealized net gains (losses) arising during the period	(729)	6,994	(107)	12,829
Less: reclassification adjustment for net gains (losses) included in net income	(567)	1,877	(1,081)	2,529
Change in unrealized gains on investments	(162)	5,117	974	10,300
Foreign currency translation adjustments	106	371	(673)	(130)
Other comprehensive income (loss)	(56)	5,488	301	10,170
Comprehensive income	$ 5,662	$ 14,828	$ 12,262	$ 25,871