CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Preferred Stock [Member]	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		$ 0	$ 28,159	$ 225,015	$ 118,412	$ 6,098	$ (11,656)
Balance at beginning of period, shares at Dec. 31, 2014		0	28,159,027				(1,385,164)
Issuance of common shares			$ 5,320	109,569
Issuance of common shares, 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			$ 43	685
Exercise of stock options, shares			42,558
Stock-based compensation				380
Dividends on common shares					(1,610)
Purchase of treasury shares							$ (651)
Purchase of treasury shares,shares							(25,278)
Net income	$ 9,764				9,764
Other comprehensive income during the period	255					255
Balance at end of period at Mar. 31, 2015	489,783	$ 0	$ 33,593	335,578	126,566	6,353	$ (12,307)
Balance at end of period, shares at Mar. 31, 2015		0	33,592,585				(1,410,442)
Balance at beginning of period at Dec. 31, 2015	514,759	$ 0	$ 33,625	337,349	152,820	3,353	$ (12,388)
Balance at beginning of period, shares at Dec. 31, 2015		0	33,625,162				(1,413,777)
Issuance of common shares			$ 2,549	69,906
Issuance of common shares, shares			2,549,469
Issuance of restricted shares			$ 97	(97)
Issuance of restricted shares, shares			96,749
Cancellation of restricted shares			$ (3)	3
Cancellation of restricted shares, shares			(3,000)
Exercise of stock options			$ 4	73
Exercise of stock options, shares			3,805
Stock-based compensation				492
Dividends on common shares					(1,742)
Purchase of treasury shares							$ (588)
Purchase of treasury shares,shares							(20,954)
Net income	12,317				12,317
Other comprehensive income during the period	3,058					3,058
Balance at end of period at Mar. 31, 2016	$ 600,828	$ 0	$ 36,272	$ 407,726	$ 163,395	$ 6,411	$ (12,976)
Balance at end of period, shares at Mar. 31, 2016		0	36,272,185				(1,434,731)