Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activities
Net income	$ 59,313,000	$ 73,612,000	$ 67,109,000
Proceeds from sales of loans held for sale	317,173,000	131,014,000	92,422,000
Originations of loans held for sale	(316,125,000)	(135,937,000)	(83,806,000)
Items not requiring (providing) cash
Depreciation	10,007,000	9,557,000	9,118,000
Amortization	2,075,000	2,068,000	2,291,000
Compensation expense for stock option grants	1,153,000	922,000	737,000
Provision for loan losses	15,871,000	6,150,000	7,150,000
Net gains on loan sales	(8,089,000)	(2,607,000)	(1,788,000)
Net realized (gains) losses on available-for-sale securities	(78,000)	62,000	(2,000)
Loss (gain) on sale of premises and equipment	(37,000)	77,000	193,000
Loss on sale/write-down of other real estate and repossessions	840,000	316,000	1,886,000
Gain on sale of business units	0	0	(7,414,000)
Accretion of deferred income, premiums, discounts and other	(6,147,000)	(3,899,000)	(2,918,000)
Loss (gain) on derivative interest rate products	264,000	104,000	(25,000)
Deferred income taxes	(11,480,000)	1,074,000	(4,450,000)
Changes in
Interest receivable	362,000	(82,000)	(1,110,000)
Prepaid expenses and other assets	(17,163,000)	(1,336,000)	3,002,000
Accrued expenses and other liabilities	(612,000)	2,725,000	280,000
Income taxes refundable/payable	(1,279,000)	2,599,000	11,520,000
Net cash provided by operating activities	46,048,000	86,419,000	94,195,000
Investing Activities
Net change in loans	(62,493,000)	(81,320,000)	(147,945,000)
Purchase of loans	(92,099,000)	(97,162,000)	(128,038,000)
Cash paid for sale of business units	0	0	(50,356,000)
Cash received for termination of interest rate derivative	45,864,000	0	0
Purchase of premises and equipment	(8,224,000)	(11,789,000)	(9,317,000)
Proceeds from sale of premises and equipment	781,000	204,000	2,328,000
Proceeds from sale of other real estate and repossessions	4,096,000	15,244,000	20,426,000
Capitalized costs on other real estate owned	(126,000)	(121,000)	(153,000)
Proceeds from maturities, calls and repayments of held-to-maturity securities	0	0	130,000
Proceeds from sale of available-for-sale securities	19,236,000	53,695,000	502,000
Proceeds from maturities, calls and repayments of available-for-sale securities	76,248,000	34,769,000	25,734,000
Purchase of available-for-sale securities	(118,296,000)	(207,634,000)	(93,378,000)
Redemption (purchase) of Federal Home Loan Bank stock and other interest-earning assets	3,667,000	(1,035,000)	(1,256,000)
Net cash used in investing activities	(131,346,000)	(295,149,000)	(381,323,000)
Financing Activities
Net increase (decrease) in certificates of deposit	(330,306,000)	129,748,000	242,955,000
Net increase (decrease) in checking and savings accounts	887,114,000	105,400,000	(53,956,000)
Proceeds from Federal Home Loan Bank advances	0	0	2,621,500,000
Repayments of Federal Home Loan Bank advances	0	0	(2,749,000,000)
Net increase (decrease) in shortterm borrowings and other interest-bearing liabilities	(146,632,000)	14,346,000	200,843,000
Advances from (to) borrowers for taxes and insurance	52,000	2,392,000	(227,000)
Proceeds from issuance of subordinated notes	73,513,000	0	0
Purchase of the company's common stock	(22,104,000)	(849,000)	(903,000)
Dividends paid	(33,426,000)	(29,052,000)	(15,819,000)
Stock options exercised	661,000	4,158,000	2,224,000
Net cash provided by financing activities	428,872,000	226,143,000	247,617,000
Increase (Decrease) in Cash and Cash Equivalents	343,574,000	17,413,000	(39,511,000)
Cash and Cash Equivalents, Beginning of Year	220,155,000	202,742,000	242,253,000
Cash and Cash Equivalents, End of Year	$ 563,729,000	$ 220,155,000	$ 202,742,000