Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities
Net income	$ 30,056,000	$ 36,139,000
Adjustments to reconcile net income to net cash from operating activities
Depreciation and amortization	6,262,000	6,997,000
Accretion of acquired loans	(337,000)	(522,000)
Provision for loan losses	11,550,000	2,450,000
Stock-based compensation expense	2,102,000	2,199,000
Stock grants to directors for retainer fee	394,000	375,000
Proceeds from sales of mortgage loans held for sale	505,602,000	163,056,000
Origination of mortgage loans held for sale	(506,683,000)	(169,661,000)
Net gain from sales of mortgage loans held for sale	(20,055,000)	(5,032,000)
Net gain from sales and valuation write-downs of foreclosed assets	(183,000)	(132,000)
Net gain from sales and valuation write-downs of former bank premises	(27,000)	(559,000)
Net loss from sales and write-downs of fixed assets	54,000	5,000
Earnings on bank owned life insurance	(933,000)	(3,567,000)
Net change in:
Accrued interest receivable	(1,080,000)	(609,000)
Other assets	(6,269,000)	(7,163,000)
Accrued interest payable and other liabilities	(4,147,000)	(3,843,000)
Net cash from operating activities	16,306,000	20,133,000
Cash flows from investing activities
Loan originations and payments, net	(472,417,000)	(168,412,000)
Purchases of securities available for sale	(270,119,000)	(53,353,000)
Proceeds from maturities, calls and repayments of securities available for sale	296,895,000	60,617,000
Proceeds from sales of foreclosed assets	313,000	632,000
Proceeds from sales of former bank premises	162,000	854,000
Purchases of Federal Home Loan Bank stock	0	(1,980,000)
Purchases of bank owned life insurance	0	(2,500,000)
Proceeds from bank owned life insurance cash value release and death benefits	0	7,708,000
Net purchases of premises and equipment	(7,201,000)	(9,109,000)
Net cash for investing activities	(452,367,000)	(165,543,000)
Cash flows from financing activities
Net increase (decrease) in time deposits	(65,389,000)	196,035,000
Net increase in all other deposits	747,039,000	107,348,000
Net increase in securities sold under agreements to repurchase	54,342,000	471,000
Maturities of Federal Home Loan Bank advances	(20,000,000)	(30,000,000)
Proceeds from Federal Home Loan Bank advances	60,000,000	44,000,000
Proceeds from stock option exercises	0	16,000
Employee stock purchase plan	37,000	39,000
Dividend reinvestment plan	610,000	541,000
Repurchases of common stock shares	(6,282,000)	(7,110,000)
Payment of cash dividends to common shareholders	(13,436,000)	(12,746,000)
Net cash from financing activities	756,921,000	298,594,000
Net change in cash and cash equivalents	320,860,000	153,184,000
Cash and cash equivalents at beginning of period	233,731,000	75,354,000
Cash and cash equivalents at end of period	554,591,000	228,538,000
Supplemental disclosures of cash flows information
Interest	21,798,000	23,361,000
Federal income tax	7,950,000	8,875,000
Transfers from loans to foreclosed assets	146,000	227,000
Transfers from bank premises to other real estate owned	$ 179,000	$ 0