Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 87,939	$ 59,504	$ 64,540
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	5,033	5,346	5,515
Deferred taxes	2,330	(2,909)	(1,412)
Stock-based compensation	850	944	859
Provision for credit losses (recovery)	(6,386)	16,047	4,819
Write-downs of other real estate owned and other repossessed assets	864	1,454	4,295
Gains on sale of loans held for sale	(6,820)	(7,226)	(1,880)
Securities gains	(60)	(1,251)	(3)
Fair value adjustment in equity securities	218	(518)	(780)
Gain on debt repurchase	0	0	(219)
(Gains) losses on sale of assets, net	(165)	390	360
Proceeds from sale of mortgage loans held for sale	307,843	347,048	94,507
Funding of mortgage loans held for sale	(280,396)	(361,913)	(91,333)
Amortization of securities premiums and discounts, net	8,010	5,907	5,042
Change in cash surrender value of bank owned life insurance	(1,873)	(1,371)	(1,567)
Payment of operating lease liabilities	(1,693)	(1,682)	(1,663)
Mortgage servicing rights:
Fair value adjustments	(428)	1,064	975
New servicing assets created	(2,278)	(1,869)	(631)
Changes in:
Accrued interest receivable	403	(982)	(404)
Other assets	4,918	1,845	4,941
Accrued interest payable	(227)	(1,596)	(63)
Other liabilities	(2,387)	4,147	(2,440)
Net cash provided by operating activities	115,695	62,379	83,458
Certificates of deposit in other banks:
Purchase of certificates of deposit	0	(245)	0
Maturity of certificates of deposit	0	245	3,675
Securities available-for-sale (AFS):
Purchase of AFS securities	(797,445)	(857,167)	(196,727)
Proceeds from sales of AFS securities	1,080	186,194	25,734
Proceeds from prepayments, calls, and maturities of AFS securities	305,361	281,487	174,125
Securities held-to-maturity (HTM):
Proceeds from prepayments and maturities of HTM securities	0	517	132
Change in loans, net	146,050	(306,523)	(46,162)
Purchase of premises and equipment	(2,373)	(1,482)	(2,570)
Proceeds from sale and retirement of premises and equipment	830	1	48
Redemption of stock by Federal Home Loan Bank	1,909	426	4,239
Proceeds from sale of other real estate owned and repossessed assets	2,819	4,754	3,641
Additional investment in bank owned life insurance	(17,181)	(1,733)	(1,241)
Proceeds from settlement of bank owned life insurance	330	0	615
Net cash used in investing activities	(358,620)	(693,526)	(34,491)
Cash flows from financing activities:
Change in deposits, net	328,210	610,510	99,622
Change in repurchase agreements and federal funds purchased, net	(84,774)	121,539	931
Advances from Federal Home Loan Bank	0	25,000	30,000
Payments on advances from Federal Home Loan Bank	(20)	(25,020)	(30,021)
Payment of finance lease liabilities	(19)	(15)	(14)
Repurchase of long-term debt	0	0	(1,281)
Issuance of common stock	965	926	1,264
Repurchase of stock	0	(1,099)	0
Dividends paid	(27,916)	(27,142)	(26,235)
Net cash provided by financing activities	216,446	704,699	74,266
Net increase (decrease) in cash and cash equivalents	(26,479)	73,552	123,233
Cash and cash equivalents at beginning of year	338,235	264,683	141,450
Cash and cash equivalents at end of year	311,756	338,235	264,683
Supplemental disclosures:
Income taxes paid	19,485	13,275	9,988
Interest paid	15,316	27,047	40,576
Non-cash activities:
Loans to facilitate the sale of other real estate owned and repossessed assets	1,733	9,632	2,879
Common stock dividends accrued, paid in subsequent quarter	248	238	221
Real estate and assets acquired in settlement of loans	$ 1,200	$ 4,446	$ 3,384