Consolidated Statements Of Changes In Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Capital Surplus[Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Dec. 31, 2014	$ 390,853	$ 46,249	$ 107,370	$ 362,211	$ (120,818)	$ (4,159)
Net income	29,975			29,975
Other comprehensive income (loss)	(733)					(733)
Cash dividends declared	(12,807)			(12,807)
Stock-based compensation expense, net	1,060		(408)		1,468
Exercise of stock options	996		(306)		1,302
Exercise of 61,796 warrants	1,896		(765)		2,661
Ending balance at Jun. 30, 2015	411,240	46,249	105,891	379,379	(115,387)	(4,892)
Beginning Balance at Dec. 31, 2015	419,272	46,249	106,269	390,690	(120,104)	(3,832)
Net income	24,244			24,244
Other comprehensive income (loss)	5,869					5,869
Cash dividends declared	(12,890)			(12,890)
Stock-based compensation expense, net	1,200		(417)		1,617
Exercise of stock options	682		(204)		886
Purchase of 231,132 treasury shares	(10,018)				(10,018)
Ending balance at Jun. 30, 2016	$ 428,359	$ 46,249	$ 105,648	$ 402,044	$ (127,619)	$ 2,037