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		$ 76,870	$ 69,829	$ 69,118
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses		(4,822)	12,342	1,575
Depreciation of premises and equipment		3,411	3,176	3,291
Net amortization of premiums and discounts on securities and loans		3,446	5,720	4,492
Amortization of intangibles		890	914	943
Share–based compensation		3,316	3,766	3,124
Tax (expense) benefit from stock option exercises and other equity awards		182	(103)	248
Deferred income tax expense (benefit)		2,155	(3,130)	(1,491)
Income from bank-owned life insurance	[1]	(2,925)	(2,491)	(2,354)
Net gains on loan sales, including changes in fair value		(28,195)	(48,005)	(14,332)
Net realized losses on securities	[1]	0	0	53
Proceeds from sales of loans, net		934,516	1,117,188	530,713
Loans originated for sale		(887,341)	(1,114,448)	(525,675)
(Increase) decrease in operating lease right-of-use assets		2,829	(2,729)	2,131
Increase (decrease) in operating lease liabilities		(2,708)	2,856	(1,992)
Increase in other assets		38,935	(57,730)	(27,961)
Increase in other liabilities		(39,747)	49,323	31,552
Net cash provided by (used in) operating activities		100,812	36,478	73,435
Cash flows from investing activities:
Purchases of mortgage-backed securities available for sale		(347,913)	(369,166)	(178,797)
Payments to Acquire Debt Securities, Available-for-sale		(251,443)	(149,899)	(27,520)
Proceeds from Sale of Debt Securities, Available-for-sale		0	0	11,877
Maturities and principal payments of mortgage-backed available for sale debt securities		337,751	351,161	147,620
Maturities and principal payments of other available for sale debt securities		82,800	176,000	108,306
Net redemption (purchases) of Federal Home Loan Bank stock		17,254	20,568	(4,785)
Purchases of other equity investments, net		(650)	0	0
Net increase in loans		(27,921)	(241,418)	(154,502)
Purchases of loans		(41,863)	(51,659)	(60,465)
Proceeds from the sale of property acquired through foreclosure or repossession		0	1,392	2,000
Purchases of premises and equipment		(3,490)	(3,406)	(3,132)
Proceeds from sale of premises		0	0	213
Purchases of bank-owned life insurance		(7,000)	0	0
Proceeds from bank-owned life insurance		1,526	787	326
Proceeds from sale of equity investment in real estate limited partnership		50	1,400	0
Equity investment in real estate limited partnership		0	0	(1,256)
Net cash provided by (used in) investing activities		(240,899)	(264,240)	(160,115)
Cash flows from financing activities:
Net increase (decrease) in deposits		601,698	879,471	(25,166)
Proceeds from Federal Home Loan Bank advances		1,294,176	1,988,500	1,982,000
Repayment of Federal Home Loan Bank advances		(1,743,036)	(2,536,105)	(1,791,258)
Proceeds from Payment Protection Program Lending Facility		0	200,628	0
Repayment of Payment Protection Program Lending Facility		0	(200,628)	0
Treasury stock purchased		0	(4,322)	0
Net proceeds from stock option exercises and issuance of other equity awards, net of awards surrendered		(177)	(470)	273
Cash dividends paid		(36,349)	(35,499)	(34,189)
Net cash provided by (used in) financing activities		116,312	291,575	131,660
Net increase in cash and cash equivalents		(23,775)	63,813	44,980
Cash and cash equivalents at beginning of year		202,268	138,455	93,475
Cash and cash equivalents at end of year		178,493	202,268	138,455
Noncash Activities:
Loans charged-off		663	1,317	2,020
Loans transferred to property acquired through foreclosure or repossession		0	313	2,000
Operating lease right-of-use assets		0	0	28,923
Operating lease liabilities		0	0	30,853
Fair value of held-to-maturity securities transferred to available for sale		0	0	10,316
Supplemental Disclosures:
Interest payments		18,313	45,294	64,496
Income tax payments		$ 19,641	$ 21,094	$ 19,759

[1] As reported in the Consolidated Statements of Income.