Loans - Risk Categories of Loans by Class of Loans (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	$ 187,955		$ 974,245
One year prior to current fiscal year	897,251		2,264,733
Two years prior to current fiscal year	2,224,016		2,112,263
Three years prior to current fiscal year	2,077,068		804,167
Four years prior to current fiscal year	783,175		797,510
Prior	2,695,183		2,015,489
Revolving	1,113,404		1,094,533
Total	9,978,052		10,062,940
Current fiscal year, Charge Offs	0		1,272
One year prior to current fiscal year, Charge Offs	215		2,027
Two years prior to current fiscal year, Charge Offs	159		2,888
Three years prior to current fiscal year, Charge Offs	1,759		3,413
Four years prior to current fiscal year, Charge Offs	139		845
Prior, Charge Offs	2,067		13,409
Revolving, Charge Offs	289		941
Total, Charge Offs	4,628	$ 3,605	24,795
Construction and land development
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	13,176		80,750
One year prior to current fiscal year	89,480		296,450
Two years prior to current fiscal year	241,903		107,158
Three years prior to current fiscal year	77,568		20,199
Four years prior to current fiscal year	9,467		21,942
Prior	41,574		29,794
Revolving	150,078		211,329
Total	623,246		767,622
Current fiscal year, Charge Offs	0		0
One year prior to current fiscal year, Charge Offs	0		0
Two years prior to current fiscal year, Charge Offs	0		0
Three years prior to current fiscal year, Charge Offs	0		0
Four years prior to current fiscal year, Charge Offs	0		0
Prior, Charge Offs	0		0
Revolving, Charge Offs	0		0
Total, Charge Offs	0	0	0
Construction and land development | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	13,176		80,750
One year prior to current fiscal year	89,480		295,043
Two years prior to current fiscal year	241,691		107,158
Three years prior to current fiscal year	77,568		20,199
Four years prior to current fiscal year	9,467		21,942
Prior	40,599		28,902
Revolving	149,619		210,716
Total	621,600		764,710
Construction and land development | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		0
One year prior to current fiscal year	0		1,407
Two years prior to current fiscal year	0		0
Three years prior to current fiscal year	0		0
Four years prior to current fiscal year	0		0
Prior	395		393
Revolving	360		289
Total	755		2,089
Construction and land development | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		0
One year prior to current fiscal year	0		0
Two years prior to current fiscal year	212		0
Three years prior to current fiscal year	0		0
Four years prior to current fiscal year	0		0
Prior	580		499
Revolving	99		324
Total	891		823
Construction and land development | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		0
One year prior to current fiscal year	0		0
Two years prior to current fiscal year	0		0
Three years prior to current fiscal year	0		0
Four years prior to current fiscal year	0		0
Prior	0		0
Revolving	0		0
Total	0		0
Commercial real estate - owner occupied
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	23,996		145,642
One year prior to current fiscal year	142,467		278,567
Two years prior to current fiscal year	279,829		284,262
Three years prior to current fiscal year	279,708		172,466
Four years prior to current fiscal year	173,803		179,537
Prior	725,180		572,790
Revolving	31,147		37,017
Total	1,656,130		1,670,281
Current fiscal year, Charge Offs	0		0
One year prior to current fiscal year, Charge Offs	0		0
Two years prior to current fiscal year, Charge Offs	0		0
Three years prior to current fiscal year, Charge Offs	0		0
Four years prior to current fiscal year, Charge Offs	0		0
Prior, Charge Offs	0		0
Revolving, Charge Offs	0		0
Total, Charge Offs	0	0	0
Commercial real estate - owner occupied | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	21,932		145,642
One year prior to current fiscal year	142,467		272,384
Two years prior to current fiscal year	273,030		281,870
Three years prior to current fiscal year	277,164		165,475
Four years prior to current fiscal year	166,881		171,897
Prior	696,218		551,177
Revolving	31,147		36,952
Total	1,608,839		1,625,397
Commercial real estate - owner occupied | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	2,064		0
One year prior to current fiscal year	0		159
Two years prior to current fiscal year	368		1,335
Three years prior to current fiscal year	1,320		0
Four years prior to current fiscal year	0		524
Prior	9,502		9,122
Revolving	0		1
Total	13,254		11,141
Commercial real estate - owner occupied | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		0
One year prior to current fiscal year	0		6,024
Two years prior to current fiscal year	6,431		1,057
Three years prior to current fiscal year	1,224		6,991
Four years prior to current fiscal year	6,922		7,116
Prior	19,460		12,491
Revolving	0		64
Total	34,037		33,743
Commercial real estate - owner occupied | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		0
One year prior to current fiscal year	0		0
Two years prior to current fiscal year	0		0
Three years prior to current fiscal year	0		0
Four years prior to current fiscal year	0		0
Prior	0		0
Revolving	0		0
Total	0		0
Commercial real estate - non-owner occupied
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	61,739		234,226
One year prior to current fiscal year	235,785		814,591
Two years prior to current fiscal year	843,552		668,314
Three years prior to current fiscal year	686,200		301,109
Four years prior to current fiscal year	300,112		407,458
Prior	1,217,064		867,988
Revolving	23,887		26,204
Total	3,368,339		3,319,890
Current fiscal year, Charge Offs	0		0
One year prior to current fiscal year, Charge Offs	0		0
Two years prior to current fiscal year, Charge Offs	0		11
Three years prior to current fiscal year, Charge Offs	0		0
Four years prior to current fiscal year, Charge Offs	84		0
Prior, Charge Offs	0		0
Revolving, Charge Offs	0		109
Total, Charge Offs	84	109	120
Commercial real estate - non-owner occupied | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	61,739		234,226
One year prior to current fiscal year	235,785		784,525
Two years prior to current fiscal year	814,204		657,499
Three years prior to current fiscal year	671,176		288,747
Four years prior to current fiscal year	287,896		397,031
Prior	1,179,616		841,062
Revolving	23,637		25,954
Total	3,274,053		3,229,044
Commercial real estate - non-owner occupied | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		0
One year prior to current fiscal year	0		29,381
Two years prior to current fiscal year	29,348		2,092
Three years prior to current fiscal year	6,418		2,964
Four years prior to current fiscal year	2,952		0
Prior	10,352		12,120
Revolving	0		0
Total	49,070		46,557
Commercial real estate - non-owner occupied | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		0
One year prior to current fiscal year	0		685
Two years prior to current fiscal year	0		8,723
Three years prior to current fiscal year	8,606		9,398
Four years prior to current fiscal year	9,264		10,427
Prior	27,096		14,806
Revolving	250		250
Total	45,216		44,289
Commercial real estate - non-owner occupied | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		0
One year prior to current fiscal year	0		0
Two years prior to current fiscal year	0		0
Three years prior to current fiscal year	0		0
Four years prior to current fiscal year	0		0
Prior	0		0
Revolving	0		0
Total	0		0
Residential real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	35,352		177,303
One year prior to current fiscal year	176,766		450,366
Two years prior to current fiscal year	472,335		650,005
Three years prior to current fiscal year	648,359		161,012
Four years prior to current fiscal year	158,118		95,660
Prior	507,690		423,161
Revolving	522,779		488,185
Total	2,521,399		2,445,692
Current fiscal year, Charge Offs	0		0
One year prior to current fiscal year, Charge Offs	0		0
Two years prior to current fiscal year, Charge Offs	0		0
Three years prior to current fiscal year, Charge Offs	0		44
Four years prior to current fiscal year, Charge Offs	0		0
Prior, Charge Offs	0		159
Revolving, Charge Offs	0		153
Total, Charge Offs	0	159	356
Residential real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	35,352		177,000
One year prior to current fiscal year	176,395		450,366
Two years prior to current fiscal year	472,223		649,086
Three years prior to current fiscal year	647,547		160,889
Four years prior to current fiscal year	157,927		95,288
Prior	497,194		413,719
Revolving	513,044		479,047
Total	2,499,682		2,425,395
Residential real estate | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		208
One year prior to current fiscal year	112		0
Two years prior to current fiscal year	0		0
Three years prior to current fiscal year	721		0
Four years prior to current fiscal year	39		58
Prior	1,134		482
Revolving	4,052		4,004
Total	6,058		4,752
Residential real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		95
One year prior to current fiscal year	259		0
Two years prior to current fiscal year	112		919
Three years prior to current fiscal year	91		123
Four years prior to current fiscal year	152		314
Prior	9,362		8,960
Revolving	5,683		5,134
Total	15,659		15,545
Residential real estate | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		0
One year prior to current fiscal year	0		0
Two years prior to current fiscal year	0		0
Three years prior to current fiscal year	0		0
Four years prior to current fiscal year	0		0
Prior	0		0
Revolving	0		0
Total	0		0
Commercial and financial
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	49,338		315,696
One year prior to current fiscal year	234,926		356,796
Two years prior to current fiscal year	333,184		355,820
Three years prior to current fiscal year	344,153		129,454
Four years prior to current fiscal year	123,117		72,557
Prior	157,547		102,305
Revolving	323,934		275,260
Total	1,566,199		1,607,888
Current fiscal year, Charge Offs	0		1,198
One year prior to current fiscal year, Charge Offs	0		117
Two years prior to current fiscal year, Charge Offs	85		659
Three years prior to current fiscal year, Charge Offs	266		3,007
Four years prior to current fiscal year, Charge Offs	0		582
Prior, Charge Offs	2,031		12,584
Revolving, Charge Offs	274		418
Total, Charge Offs	2,656	2,642	18,565
Commercial and financial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	49,338		315,560
One year prior to current fiscal year	233,844		336,071
Two years prior to current fiscal year	312,888		333,113
Three years prior to current fiscal year	322,298		127,069
Four years prior to current fiscal year	120,778		66,165
Prior	141,193		89,002
Revolving	318,118		269,108
Total	1,498,457		1,536,088
Commercial and financial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		136
One year prior to current fiscal year	1,082		2,167
Two years prior to current fiscal year	1,206		1,064
Three years prior to current fiscal year	935		1,005
Four years prior to current fiscal year	985		503
Prior	1,468		1,103
Revolving	1,742		2,191
Total	7,418		8,169
Commercial and financial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		0
One year prior to current fiscal year	0		18,558
Two years prior to current fiscal year	19,090		21,643
Three years prior to current fiscal year	20,920		1,380
Four years prior to current fiscal year	1,354		5,889
Prior	14,886		11,842
Revolving	4,074		3,961
Total	60,324		63,273
Commercial and financial | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		0
One year prior to current fiscal year	0		0
Two years prior to current fiscal year	0		0
Three years prior to current fiscal year	0		0
Four years prior to current fiscal year	0		0
Prior	0		358
Revolving	0		0
Total	0		358
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	4,354		20,628
One year prior to current fiscal year	17,827		67,963
Two years prior to current fiscal year	53,213		46,704
Three years prior to current fiscal year	41,080		19,927
Four years prior to current fiscal year	18,558		20,356
Prior	46,128		19,451
Revolving	61,579		56,538
Total	242,739		251,567
Current fiscal year, Charge Offs	0		74
One year prior to current fiscal year, Charge Offs	215		1,910
Two years prior to current fiscal year, Charge Offs	74		2,218
Three years prior to current fiscal year, Charge Offs	1,493		362
Four years prior to current fiscal year, Charge Offs	55		263
Prior, Charge Offs	36		666
Revolving, Charge Offs	15		261
Total, Charge Offs	1,888	$ 695	5,754
Consumer | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	4,354		20,557
One year prior to current fiscal year	17,757		66,699
Two years prior to current fiscal year	49,663		45,534
Three years prior to current fiscal year	39,083		19,747
Four years prior to current fiscal year	18,337		20,300
Prior	45,641		19,080
Revolving	61,400		56,473
Total	236,235		248,390
Consumer | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		5
One year prior to current fiscal year	0		334
Two years prior to current fiscal year	235		279
Three years prior to current fiscal year	217		77
Four years prior to current fiscal year	60		5
Prior	95		194
Revolving	88		65
Total	695		959
Consumer | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		66
One year prior to current fiscal year	70		930
Two years prior to current fiscal year	3,315		891
Three years prior to current fiscal year	1,780		103
Four years prior to current fiscal year	161		51
Prior	392		177
Revolving	91		0
Total	5,809		2,218
Consumer | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0		0
One year prior to current fiscal year	0		0
Two years prior to current fiscal year	0		0
Three years prior to current fiscal year	0		0
Four years prior to current fiscal year	0		0
Prior	0		0
Revolving	0		0
Total	$ 0		$ 0