PARENT COMPANY FINANCIAL INFORMATION - CONDENSED STATEMENTS OF CASH FLOWS (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income	$ 3,654	$ 2,896	$ 2,968	$ 2,964	$ 2,884	$ 2,633	$ 3,123	$ 2,834	$ 12,482	$ 11,474	$ 9,869
Adjustments for non-cash items -
NET CASH FLOWS FROM OPERATING ACTIVITIES									15,484	13,239	15,940
Cash flows from investing activities:
Purchases of securities available-for-sale									(124,934)	(163,859)	(92,180)
Available-for-sale									84,529	29,700	36,716
Proceeds from sales of available-for-sale securities									92,455	97,981	67,296
Cash paid for business acquisition									0	8,993	(9,114)
NET CASH FLOWS USED IN INVESTING ACTIVITIES									(27,516)	(65,567)	(11,002)
Cash flows from financing activities:
Proceeds from issuance of common stock									52	66	58
Repurchase of stock warrants									(1,545)	0	0
Cash dividends paid on common stock									(6,048)	(5,915)	(5,636)
NET CASH FLOWS PROVIDED BY (USED IN) FINANCING ACTIVITIES									15,910	51,470	(3,781)
NET CHANGE IN CASH AND CASH EQUIVALENTS									3,878	(858)	1,157
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR				14,987				15,845	14,987	15,845	14,688
CASH AND CASH EQUIVALENTS AT END OF YEAR	18,865				14,987				18,865	14,987	15,845
Parent Company
Cash flows from operating activities:
Net income									12,482	11,474	9,869
Adjustments for non-cash items -
Increase in undistributed income of subsidiary									(5,814)	(6,528)	(1,695)
Other, net									126	42	(474)
NET CASH FLOWS FROM OPERATING ACTIVITIES									6,794	4,988	7,700
Cash flows from investing activities:
Purchases of securities available-for-sale									(177)	(215)	(107)
Available-for-sale									55	0	0
Proceeds from sales of available-for-sale securities									173	1,217	227
Cash paid for business acquisition									0	(3,757)	(24,750)
NET CASH FLOWS USED IN INVESTING ACTIVITIES									51	(2,755)	(24,630)
Cash flows from financing activities:
Proceeds from issuance of common stock									379	390	372
Repurchase of stock warrants									(1,545)	0	0
Cash dividends paid on common stock									(6,375)	(6,239)	(5,950)
Other									653	165	0
NET CASH FLOWS PROVIDED BY (USED IN) FINANCING ACTIVITIES									(6,888)	(5,684)	(5,578)
NET CHANGE IN CASH AND CASH EQUIVALENTS									(43)	(3,451)	(22,508)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR				$ 534				$ 3,985	534	3,985	26,493
CASH AND CASH EQUIVALENTS AT END OF YEAR	$ 491				$ 534				$ 491	$ 534	$ 3,985