Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities
Net income	$ 23,295,000	$ 23,828,000
Adjustments to reconcile net income to net cash from operating activities
Depreciation and amortization	7,820,000	6,730,000
Accretion of acquired loans	(1,867,000)	(3,253,000)
Provision for loan losses	2,350,000	2,300,000
Stock-based compensation expense	1,431,000	901,000
Stock grants to directors for retainer fee	363,000	327,000
Proceeds from sales of mortgage loans held for sale	81,368,000	83,440,000
Origination of mortgage loans held for sale	(81,570,000)	(83,000,000)
Net gain from sales of mortgage loans held for sale	(2,875,000)	(2,463,000)
Gain on trust preferred securities repurchase	0	(2,970,000)
Net gain from sales and valuation write-down of foreclosed assets	(199,000)	(322,000)
Net (gain) loss from sales and valuation write-down of former bank premises	123,000	(10,000)
Net loss from sales of fixed assets	67,000	174,000
Net (gain) loss from sales of available for sale securities	(36,000)	1,000
Earnings on bank owned life insurance	(2,394,000)	(933,000)
Net change in:
Accrued interest receivable	(1,404,000)	(228,000)
Other assets	(1,987,000)	(1,554,000)
Accrued interest and other liabilities	278,000	(809,000)
Net cash from operating activities	24,763,000	22,159,000
Cash flows from investing activities
Loan originations and payments, net	(172,665,000)	(124,126,000)
Purchases of securities available for sale	(50,276,000)	(130,414,000)
Proceeds from maturities, calls and repayments of securities available for sale	46,177,000	152,781,000
Proceeds from sales of securities available for sale	6,706,000	264,000
Proceeds from sales of foreclosed assets	772,000	1,458,000
Proceeds from sales of former bank premises	22,000	45,000
Purchases of Federal Home Loan Bank stock	(3,010,000)	(459,000)
Proceeds from bank owned life insurance cash value release and death benefits	2,720,000	0
Purchases of bank owned life insurance	0	(7,000,000)
Net purchases of premises and equipment	(4,192,000)	(1,051,000)
Net cash for investing activities	(173,746,000)	(108,502,000)
Cash flows from financing activities
Net increase (decrease) in time deposits	(49,466,000)	17,823,000
Net increase in all other deposits	163,524,000	36,232,000
Net decrease in securities sold under agreements to repurchase	(9,430,000)	(7,928,000)
Maturities of Federal Home Loan Bank advances	(45,000,000)	0
Proceeds from Federal Home Loan Bank advances	90,000,000	110,000,000
Proceeds from stock option exercises	289,000	606,000
Employee stock purchase plan	36,000	27,000
Dividend reinvestment plan	1,426,000	1,079,000
Repurchase of common stock shares	0	(3,732,000)
Repurchase of trust preferred securities	0	(8,030,000)
Payment of cash dividends to common shareholders	(8,941,000)	(7,895,000)
Net cash from financing activities	142,438,000	138,182,000
Net change in cash and cash equivalents	(6,545,000)	51,839,000
Cash and cash equivalents at beginning of period	183,596,000	89,891,000
Cash and cash equivalents at end of period	177,051,000	141,730,000
Supplemental disclosures of cash flows information
Interest	11,064,000	9,218,000
Federal income tax	10,275,000	10,950,000
Noncash financing and investing activities:
Transfers from loans to foreclosed assets	839,000	297,000
Transfers from bank premises to other real estate owned	$ 1,737,000	$ 371,000