CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income, Net of Tax [Member] Available-for-sale Securities [Member]	Treasury Stock [Member]
Balance at beginning of period at Dec. 31, 2014		$ 28,159	$ 225,015	$ 118,412	$ 6,098	$ (11,656)
Balance at beginning of period, shares at Dec. 31, 2014		28,159,027				1,385,164
Issuance of common stock		$ 5,320	109,569
Issuance of common stock ,shares		5,320,000
Issuance of restricted shares		$ 71	(71)
Issuance of restricted shares, shares		71,000
Cancellation of restricted shares		$ 0	0
Cancellation of restricted shares, shares		0
Exercise of stock options		$ 59	939
Exercise of stock options, shares		58,839
Stock-based compensation			760
Dividends on common shares				(3,219)
Purchase of treasury shares						$ (732)
Purchase of treasury shares,shares						28,613
Net income	$ 11,072			11,072
Other comprehensive income during the period	(3,026)				(3,026)
Balance at end of period at Jun. 30, 2015	486,770	$ 33,609	336,212	126,265	3,072	$ (12,388)
Balance at end of period, shares at Jun. 30, 2015		33,608,866				1,413,777
Balance at beginning of period at Dec. 31, 2015	514,759	$ 33,625	337,349	152,820	3,353	$ (12,388)
Balance at beginning of period, shares at Dec. 31, 2015		33,625,162				1,413,777
Issuance of common stock		$ 2,549	69,906
Issuance of common stock ,shares		2,549,469
Issuance of restricted shares		$ 111	(111)
Issuance of restricted shares, shares		110,653
Cancellation of restricted shares		$ (3)	3
Cancellation of restricted shares, shares		(3,085)
Exercise of stock options		$ 21	393
Exercise of stock options, shares		20,964
Stock-based compensation			1,009
Dividends on common shares				(3,485)
Purchase of treasury shares						$ (1,210)
Purchase of treasury shares,shares						42,075
Net income	32,366			32,366
Other comprehensive income during the period	9,607				9,607
Balance at end of period at Jun. 30, 2016	$ 625,915	$ 36,303	$ 408,549	$ 181,701	$ 12,960	$ (13,598)
Balance at end of period, shares at Jun. 30, 2016		36,303,163				1,455,852