Allowance for Credit Losses and Allowance for Unfunded Commitments and Letters of Credit (Analysis of Credit Quality of the Loan Portfolio) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 1,848,505		$ 2,745,438
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,479,519		1,490,732
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,301,636		1,201,138
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,037,293		854,212
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	708,420		798,466
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,995,703		1,751,150
Financing Receivable, Revolving	2,294,462		1,748,587
Financing Receivable, Revolving Converted to Term Loans	26,723		52,214
Loans and Leases Receivable, Net of Deferred Income	11,692,261		10,641,937
Financing Receivable, Allowance for Credit Loss	154,871	$ 149,935	155,578	$ 142,785	$ 142,988	$ 149,140
Loans, net	11,537,390		10,486,359
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	983,823		1,074,864
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,031,206		766,442
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	699,078		715,378
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	657,485		507,656
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	435,840		545,313
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,483,455		1,289,984
Financing Receivable, Revolving	75,232		75,783
Financing Receivable, Revolving Converted to Term Loans	8,932		5,843
Loans and Leases Receivable, Net of Deferred Income	5,375,051		4,981,263
Financing Receivable, Allowance for Credit Loss	57,381	57,119	61,254	51,752	53,250	68,934
Commercial Real Estate [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	983,823		1,068,493
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,021,822		760,545
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	688,119		650,593
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	603,943		492,348
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	431,582		515,233
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,402,281		1,180,115
Financing Receivable, Revolving	71,235		74,754
Financing Receivable, Revolving Converted to Term Loans	8,932		3,644
Loans and Leases Receivable, Net of Deferred Income	5,211,737		4,745,725
Commercial Real Estate [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0		2,252
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,865		0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	3,566		19,016
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	19,591		6,196
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0		163
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	11,763		27,270
Financing Receivable, Revolving	0		0
Financing Receivable, Revolving Converted to Term Loans	0		2,199
Loans and Leases Receivable, Net of Deferred Income	36,785		57,096
Commercial Real Estate [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0		4,119
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	7,519		5,897
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	7,393		45,769
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	33,951		9,112
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4,258		29,917
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	69,411		82,599
Financing Receivable, Revolving	3,997		1,029
Financing Receivable, Revolving Converted to Term Loans	0		0
Loans and Leases Receivable, Net of Deferred Income	126,529		178,442
Commercial Business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	439,306		896,907
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	727,114		430,749
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	369,448		305,313
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	248,838		246,418
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	202,809		165,036
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	301,999		259,869
Financing Receivable, Revolving	1,485,879		1,081,668
Financing Receivable, Revolving Converted to Term Loans	8,303		37,308
Loans and Leases Receivable, Net of Deferred Income	3,783,696		3,423,268
Financing Receivable, Allowance for Credit Loss	54,085	51,985	54,712	55,561	57,554	45,250
Commercial Business [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	436,851		891,957
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	713,165		426,004
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	364,061		280,823
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	224,851		217,605
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	180,781		144,363
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	272,401		232,356
Financing Receivable, Revolving	1,413,129		1,028,616
Financing Receivable, Revolving Converted to Term Loans	6,807		35,411
Loans and Leases Receivable, Net of Deferred Income	3,612,046		3,257,135
Commercial Business [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	2,362		621
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	10,652		135
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,564		6,097
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6,588		747
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	392		105
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	653		51
Financing Receivable, Revolving	28,105		34,256
Financing Receivable, Revolving Converted to Term Loans	425		236
Loans and Leases Receivable, Net of Deferred Income	50,741		42,248
Commercial Business [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	93		4,329
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,297		4,610
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	3,823		18,393
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	17,399		28,066
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	21,636		20,568
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	28,945		27,462
Financing Receivable, Revolving	44,645		18,796
Financing Receivable, Revolving Converted to Term Loans	1,071		1,661
Loans and Leases Receivable, Net of Deferred Income	120,909		123,885
Agriculture [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	114,516		147,723
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	130,916		95,681
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	77,697		84,251
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	74,406		31,355
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	24,264		51,590
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	105,071		81,526
Financing Receivable, Revolving	375,230		296,263
Financing Receivable, Revolving Converted to Term Loans	1,160		7,326
Loans and Leases Receivable, Net of Deferred Income	903,260		795,715
Financing Receivable, Allowance for Credit Loss	9,433	8,895	8,148	8,965	7,920	9,052
Agriculture [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	113,968		147,561
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	129,433		87,964
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	72,571		74,658
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	69,576		29,739
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	24,244		46,058
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	103,310		79,693
Financing Receivable, Revolving	346,565		266,573
Financing Receivable, Revolving Converted to Term Loans	1,160		5,448
Loans and Leases Receivable, Net of Deferred Income	860,827		737,694
Agriculture [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0		162
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	140		0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0		445
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	4,306		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0		0
Financing Receivable, Revolving	899		565
Financing Receivable, Revolving Converted to Term Loans	0		0
Loans and Leases Receivable, Net of Deferred Income	5,345		1,172
Agriculture [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	548		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,343		7,717
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	5,126		9,148
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	524		1,616
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	20		5,532
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,761		1,833
Financing Receivable, Revolving	27,766		29,125
Financing Receivable, Revolving Converted to Term Loans	0		1,878
Loans and Leases Receivable, Net of Deferred Income	37,088		56,849
Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	176,863		228,661
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	222,701		53,880
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	27,571		37,543
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	15,842		3,183
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	3,066		3,285
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	3,516		2,438
Financing Receivable, Revolving	55,628		55,765
Financing Receivable, Revolving Converted to Term Loans	7,121		0
Loans and Leases Receivable, Net of Deferred Income	512,308		384,755
Financing Receivable, Allowance for Credit Loss	8,147	5,914	5,397	6,367	6,559	7,636
Construction [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	176,863		228,661
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	221,956		53,880
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	27,571		35,795
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	14,115		3,183
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,618		3,285
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	3,466		2,189
Financing Receivable, Revolving	55,628		55,765
Financing Receivable, Revolving Converted to Term Loans	7,121		0
Loans and Leases Receivable, Net of Deferred Income	509,338		382,758
Construction [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	745
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Financing Receivable, Revolving	0
Financing Receivable, Revolving Converted to Term Loans	0
Loans and Leases Receivable, Net of Deferred Income	745
Construction [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0		0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0		1,748
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,727		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	448		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	50		249
Financing Receivable, Revolving	0		0
Financing Receivable, Revolving Converted to Term Loans	0		0
Loans and Leases Receivable, Net of Deferred Income	2,225		1,997
One-to-Four Family Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	126,882		390,238
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	364,441		141,269
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	126,363		56,703
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	39,728		52,111
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	40,862		32,681
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	92,683		116,043
Financing Receivable, Revolving	279,163		223,232
Financing Receivable, Revolving Converted to Term Loans	1,100		1,631
Loans and Leases Receivable, Net of Deferred Income	1,071,222		1,013,908
Financing Receivable, Allowance for Credit Loss	24,014	24,626	24,123	18,855	16,519	16,875
One-to-Four Family Residential [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	126,882		390,153
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	364,441		140,799
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	126,287		56,520
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	39,728		51,549
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	40,319		32,447
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	91,542		111,307
Financing Receivable, Revolving	278,903		222,747
Financing Receivable, Revolving Converted to Term Loans	856		1,347
Loans and Leases Receivable, Net of Deferred Income	1,068,958		1,006,869
One-to-Four Family Residential [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0		85
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0		470
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	76		183
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0		562
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	543		234
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,141		4,736
Financing Receivable, Revolving	260		485
Financing Receivable, Revolving Converted to Term Loans	244		284
Loans and Leases Receivable, Net of Deferred Income	2,264		7,039
Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	7,115		7,045
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,141		2,711
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,479		1,950
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	994		13,489
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,579		561
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	8,979		1,290
Financing Receivable, Revolving	23,330		15,876
Financing Receivable, Revolving Converted to Term Loans	107		106
Loans and Leases Receivable, Net of Deferred Income	46,724		43,028
Financing Receivable, Allowance for Credit Loss	1,811	$ 1,396	1,944	$ 1,285	$ 1,186	$ 1,393
Consumer Loan [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	7,115		7,045
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,121		2,711
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,479		1,950
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	994		13,489
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,579		560
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	8,969		1,277
Financing Receivable, Revolving	23,328		15,853
Financing Receivable, Revolving Converted to Term Loans	107		97
Loans and Leases Receivable, Net of Deferred Income	46,692		42,982
Consumer Loan [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	20		0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0		0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0		1
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	10		13
Financing Receivable, Revolving	2		23
Financing Receivable, Revolving Converted to Term Loans	0		9
Loans and Leases Receivable, Net of Deferred Income	$ 32		$ 46