CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 35,331,000	$ 23,828,000	$ 27,381,000
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of discounts and premiums on securities	3,788,000	4,344,000	4,265,000
(Gain) loss on sale of securities available-for-sale	(266,000)	6,000	(1,099,000)
Gain on sale of SBA loans	(698,000)	(1,108,000)	(796,000)
Proceeds from sale of SBA loans originated for sale	11,765,000	14,733,000	11,371,000
SBA loans originated for sale	(15,214,000)	(13,730,000)	(14,434,000)
Provision for loan losses	7,421,000	99,000	1,237,000
Increase in cash surrender value of life insurance	(1,045,000)	(1,666,000)	(1,747,000)
Gain on proceeds from company owned life insurance			(1,119,000)
Depreciation and amortization	753,000	786,000	763,000
Amortization of other intangible assets	1,943,000	1,361,000	1,568,000
Stock option expense, net	708,000	838,000	937,000
Amortization of restricted stock awards, net	1,109,000	912,000	479,000
Amortization of subordinated debt issuance costs	186,000	110,000
Effect of changes in:
Accrued interest receivable and other assets	1,572,000	10,497,000	(1,238,000)
Accrued interest payable and other liabilities	1,219,000	348,000	(1,669,000)
Net cash provided by operating activities	48,572,000	41,358,000	25,899,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of securities available-for-sale	(162,806,000)	(144,898,000)	(75,803,000)
Purchase of securities held-to-maturity	(31,496,000)	(120,505,000)	(239,441,000)
Maturities/paydowns/calls of securities available-for-sale	57,142,000	57,862,000	67,562,000
Maturities/paydowns/calls of securities held-to-maturity	50,773,000	44,277,000	23,415,000
Proceeds from sales of securities available-for-sale	94,291,000	6,536,000	75,689,000
Net change in loans	38,394,000	(77,199,000)	(139,792,000)
Changes in Federal Home Loan Bank stock and other investments	(4,483,000)	(2,715,000)	(2,502,000)
Purchase of premises and equipment	(187,000)	(649,000)	(480,000)
Cash received in bank acquisition, net of cash paid	36,028,000
Proceeds from sale of foreclosed assets			49,000
Proceeds from company-owned life insurance			3,739,000
Net cash provided (used in) by investing activities	77,656,000	(237,291,000)	(287,564,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net change in deposits	(262,085,000)	220,849,000	199,365,000
Issuance of subordinated debt, net of issuance costs		39,073,000
Exercise of stock options	2,667,000	1,368,000	938,000
Short-term borrowings			(3,000,000)
Payment of cash dividends	(18,464,000)	(15,238,000)	(13,627,000)
Net cash (used in) provided by financing activities	(277,882,000)	246,052,000	183,676,000
Net increase (decrease) in cash and cash equivalents	(151,654,000)	50,119,000	(77,989,000)
Cash and cash equivalents, beginning of period	316,222,000	266,103,000	344,092,000
Cash and cash equivalents, end of period	164,568,000	316,222,000	266,103,000
Supplemental disclosures of cash flow information:
Interest paid	7,528,000	5,166,000	3,214,000
Income taxes paid	12,838,000	17,256,000	16,530,000
Supplemental schedule of non-cash investing activity:
Due to broker for securities purchased			6,693,000
Transfer of loans held-for-sale to loan portfolio	$ 4,917,000	$ 2,391,000	5,451,000
Loans transferred to foreclosed assets			$ 278,000