Consolidated Statement of Changes in Shareholders' Equity - USD ($) $ in Thousands	Common Stock	Capital Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total
BALANCE-beginning of period at Dec. 31, 2014	$ 262	$ 252,421	$ 34,660	$ 1,062	$ 288,405
BALANCE-beginning of period (in shares) at Dec. 31, 2014	26,176,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			4,649		4,649
Net change in unrealized gains and losses on available-for-sale securities, net of taxes and reclassification adjustment				485	485
Issuance of common stock in connection with the exercise of stock options		2			2
Stock-based compensation expense		229			229
BALANCE-end of period at Mar. 31, 2015	$ 262	252,652	39,309	1,547	293,770
BALANCE-end of period (in shares) at Mar. 31, 2015	26,176,000
BALANCE-beginning of period at Dec. 31, 2015	$ 368	378,518	50,099	417	429,402
BALANCE-beginning of period (in shares) at Dec. 31, 2015	36,788,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			1,839		1,839
Net change in unrealized gains and losses on available-for-sale securities, net of taxes and reclassification adjustment				595	595
Purchase of treasury stock					$ 1,253
Purchase of treasury stock (in shares)					(1,253)
Stock-based compensation expense		327			$ 327
BALANCE-end of period at Mar. 31, 2016	$ 368	$ 378,845	$ 51,938	$ 1,012	$ 430,910
BALANCE-end of period (in shares) at Mar. 31, 2016	36,788,000