PARENT COMPANY STATEMENTS (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	$ 13,522	$ 13,480	$ 12,803	$ 12,279	$ 12,286	$ 11,565	$ 11,380	$ 11,136	$ 52,084	$ 46,367	$ 43,805
Cash flows from financing activities
Repurchase of common stock									(458)	(455)	(444)
Net increase in cash and cash equivalents									86,606	(9,964)	27,533
Cash and cash equivalents at beginning of the year				80,674				90,638	80,674	90,638	63,105
Cash and cash equivalents at end of the year	167,280				80,674				167,280	80,674	90,638
Parent Company [Member]
Cash flows from operating activities:
Net income									52,084	46,367	43,805
Adjustments to net cash from operating activities:
Equity in undistributed income of subsidiaries									(34,090)	(37,620)	(28,080)
Other changes									3,818	3,647	5,348
Net cash from operating activities									21,812	12,394	21,073
Cash flows from financing activities
Proceeds from issuance of common stock									614	12	57
Repurchase of common stock									(458)	(455)	(444)
Dividends paid									(18,200)	(15,697)	(13,555)
Cash flows from financing activities									(18,044)	(16,140)	(13,942)
Net increase in cash and cash equivalents									3,768	(3,746)	7,131
Cash and cash equivalents at beginning of the year				$ 4,335				$ 8,081	4,335	8,081	950
Cash and cash equivalents at end of the year	$ 8,103				$ 4,335				$ 8,103	$ 4,335	$ 8,081