CONDENSED FINANCIAL INFORMATION OF PARENT COMPANY (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets
Cash and interest-bearing deposits in banks	$ 45,142	$ 43,488
Securities available-for-sale	276,984	341,665
Other assets	4,997	4,656
Total assets	1,936,740	1,851,160
Liabilities:
Notes payable	26,277	27,703
Junior subordinated debentures	22,167	29,384
ESOP obligation	(250)	0
Other	6,952	5,605
Total liabilities	1,727,728	1,660,411
Total stockholders' equity	209,012	190,749	189,241	161,837
Total liabilities and stockholders' equity	1,936,740	1,851,160
Expenses:
Professional fees	1,802	1,709	2,022
Income before income taxes	26,468	20,327	13,421
Income tax benefit	(7,358)	(6,151)	(3,779)
Net earnings	19,110	14,176	9,642
Cash flows from operating activities:
Net earnings	19,110	14,176	9,642
Adjustments to reconcile net earnings to net cash provided by operating activities:
Net cash provided by operating activities	29,758	25,884	17,947
Cash flows from investing activities:
Purchase of securities available-for-sale	(1,250)	(68,043)	(100,384)
Proceeds from prepayments of securities available-for-sale	48,464	72,728	146,019
Net cash used in investing activities	(65,313)	(38,931)	(5,296)
Cash flows from financing activities:
Proceeds from exercise of stock options	643	69	100
Payment of preferred dividends	(704)	(1,519)	(1,579)
Payment of common dividends	(3,838)	(3,320)	(2,932)
Purchase of treasury stock	(9)	0	0
Repayment of long-term debt	(1,000)	(1,000)	0
Net cash provided by (used in) financing activities	62,696	(795)	(22,381)
Net increase (decrease) in cash and cash equivalents	27,141	(13,842)	(9,730)
Cash and cash equivalents, beginning of year	59,731	73,573	83,303
Cash and cash equivalents, end of year	86,872	59,731	73,573
Parent Company [Member]
Assets
Cash and interest-bearing deposits in banks	9,452	7,879
Securities available-for-sale	1,218	735
Other assets	4,486	2,642
Investment in and advances to subsidiaries	219,216	211,494
Total assets	234,372	222,750
Liabilities:
Dividends payable	1,208	1,093
Notes payable	0	1,000
Junior subordinated debentures	22,167	29,384
ESOP obligation	250	0
Other	1,735	524
Total liabilities	25,360	32,001
Total stockholders' equity	209,012	190,749
Total liabilities and stockholders' equity	234,372	222,750
Revenue:
Dividends from Bank and nonbank subsidiaries	15,500	11,000	0
Rental and other income	87	125	102
Total revenue	15,587	11,125	102
Expenses:
Interest on short- and long-term debt	1,087	1,415	984
Professional fees	217	345	804
Other expenses	844	547	1,126
Total expenses	2,148	2,307	2,914
Income before income taxes	13,439	8,818	(2,812)
Equity in undistributed earnings of subsidiaries	4,955	4,600	11,477
Income tax benefit	716	758	977
Net earnings	19,110	14,176	9,642
Cash flows from operating activities:
Net earnings	19,110	14,176	9,642
Adjustments to reconcile net earnings to net cash provided by operating activities:
Undistributed earnings of subsidiaries	(4,955)	(4,600)	(11,477)
Other, net	(872)	(668)	(2,306)
Net cash provided by operating activities	13,283	8,908	(4,141)
Cash flows from investing activities:
Purchase of securities available-for-sale	0	(464)	0
Proceeds from prepayments of securities available-for-sale	198	0	0
Outlays for business acquisition, net of cash acquired	0	0	(14,360)
Other, net	217	223	0
Net cash used in investing activities	415	(241)	(14,360)
Cash flows from financing activities:
Proceeds from exercise of stock options	643	69	100
Payment of preferred dividends	(704)	(1,519)	(1,579)
Payment of common dividends	(3,838)	(3,320)	(2,932)
Purchase of treasury stock	(9)	0	0
Repayment of long-term debt	(8,217)	(1,000)	0
Net cash provided by (used in) financing activities	(12,125)	(5,770)	(4,411)
Net increase (decrease) in cash and cash equivalents	1,573	2,897	(22,912)
Cash and cash equivalents, beginning of year	7,879	4,982	27,894
Cash and cash equivalents, end of year	$ 9,452	$ 7,879	$ 4,982