Loans and Allowance for Credit Losses Credit Quality Indicators (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Total
Total	$ 24,176,075		$ 24,176,075		$ 21,351,094
Current period gross charge-offs	(13,144)	$ (7,279)	(38,103)	$ (28,969)
Real estate - commercial mortgage
Total
Total	9,493,479		9,493,479		8,127,728
Gross loans	9,493,479		9,493,479		8,127,728
Commercial and Industrial
Total
Total	4,914,734		4,914,734		4,545,552
Gross loans	4,914,734		4,914,734		4,545,552
Real estate - residential mortgage
Total
Total	6,302,624		6,302,624		5,325,923
Gross loans	6,302,624		6,302,624		5,325,923
Leases and other loans
Total
Total	336,165		336,165		336,314
Gross loans	336,165		336,165		336,314
Portfolio Segment and Loan Class
2024
Total	932,880		932,880		1,744,297
2023
Total	2,040,068		2,040,068		1,953,966
2022
Total	2,328,640		2,328,640		1,981,737
2021
Total	2,071,193		2,071,193		1,428,026
2020
Total	1,505,258		1,505,258		1,091,506
Prior
Total	4,796,515		4,796,515		3,727,931
Revolving Loans Amortized Cost Basis
Total	1,823,403		1,823,403		1,696,870
Total
Total	15,529,480		15,529,480		13,675,866
Portfolio Segment and Loan Class | Pass
2024
Total	907,742		907,742		1,732,981
2023
Total	1,889,234		1,889,234		1,841,229
2022
Total	1,892,452		1,892,452		1,796,011
2021
Total	1,662,329		1,662,329		1,363,602
2020
Total	1,337,874		1,337,874		1,003,493
Prior
Total	4,227,139		4,227,139		3,455,090
Revolving Loans Amortized Cost Basis
Total	1,486,949		1,486,949		1,516,133
Total
Total	13,410,244		13,410,244		12,750,911
Portfolio Segment and Loan Class | Special Mention
2024
Total	15,548		15,548		10,703
2023
Total	98,939		98,939		66,074
2022
Total	317,300		317,300		147,582
2021
Total	319,897		319,897		11,439
2020
Total	85,839		85,839		42,106
Prior
Total	328,343		328,343		124,273
Revolving Loans Amortized Cost Basis
Total	165,401		165,401		74,535
Total
Total	1,335,086		1,335,086		476,910
Portfolio Segment and Loan Class | Substandard or Lower
2024
Total	9,590		9,590		613
2023
Total	51,895		51,895		46,663
2022
Total	118,888		118,888		38,144
2021
Total	88,967		88,967		52,985
2020
Total	81,545		81,545		45,907
Prior
Total	241,033		241,033		148,568
Revolving Loans Amortized Cost Basis
Total	171,053		171,053		106,202
Total
Total	784,150		784,150		448,045
Portfolio Segment and Loan Class | Real estate - commercial mortgage
2024
Total	442,356		442,356		786,806
Current period gross charge-offs			0		0
2023
Total	1,025,467		1,025,467		1,057,879
Current period gross charge-offs			(126)		0
2022
Total	1,384,269		1,384,269		1,340,341
Current period gross charge-offs			(84)		0
2021
Total	1,591,429		1,591,429		1,041,962
Current period gross charge-offs			0		0
2020
Total	1,171,046		1,171,046		783,725
Current period gross charge-offs			0		0
Prior
Total	3,789,512		3,789,512		3,023,562
Current period gross charge-offs			(10,366)		(424)
Revolving Loans Amortized Cost Basis
Total	89,076		89,076		61,817
Current period gross charge-offs			0		0
Total
Total	9,493,479		9,493,479		8,127,728
Current period gross charge-offs			(10,602)		(17,999)
Portfolio Segment and Loan Class | Real estate - commercial mortgage | Pass
2024
Total	439,628		439,628		783,673
2023
Total	927,412		927,412		993,017
2022
Total	1,144,947		1,144,947		1,203,852
2021
Total	1,304,578		1,304,578		984,958
2020
Total	1,039,538		1,039,538		721,857
Prior
Total	3,409,730		3,409,730		2,822,155
Revolving Loans Amortized Cost Basis
Total	75,822		75,822		59,253
Total
Total	8,341,979		8,341,979		7,600,401
Portfolio Segment and Loan Class | Real estate - commercial mortgage | Special Mention
2024
Total	2,514		2,514		2,767
2023
Total	61,815		61,815		43,904
2022
Total	175,721		175,721		105,185
2021
Total	209,161		209,161		7,862
2020
Total	58,007		58,007		35,289
Prior
Total	217,361		217,361		105,786
Revolving Loans Amortized Cost Basis
Total	11,271		11,271		1,760
Total
Total	735,850		735,850		302,553
Portfolio Segment and Loan Class | Real estate - commercial mortgage | Substandard or Lower
2024
Total	214		214		366
2023
Total	36,240		36,240		20,958
2022
Total	63,601		63,601		31,304
2021
Total	77,690		77,690		49,142
2020
Total	73,501		73,501		26,579
Prior
Total	162,421		162,421		95,621
Revolving Loans Amortized Cost Basis
Total	1,983		1,983		804
Total
Total	415,650		415,650		224,774
Portfolio Segment and Loan Class | Commercial and Industrial
2024
Total	351,582		351,582		634,569
Current period gross charge-offs			(370)		0
2023
Total	569,533		569,533		624,864
Current period gross charge-offs			(2,093)		(299)
2022
Total	637,514		637,514		351,686
Current period gross charge-offs			(268)		0
2021
Total	358,368		358,368		348,638
Current period gross charge-offs			(606)		0
2020
Total	324,792		324,792		297,931
Current period gross charge-offs			(280)		0
Prior
Total	940,954		940,954		648,988
Current period gross charge-offs			(5,486)		(249)
Revolving Loans Amortized Cost Basis
Total	1,700,792		1,700,792		1,621,208
Current period gross charge-offs			(4,105)		(682)
Total
Total	4,914,734		4,914,734		4,545,552
Current period gross charge-offs			(16,843)		(9,246)
Portfolio Segment and Loan Class | Commercial and Industrial | Pass
2024
Total	329,172		329,172		626,386
2023
Total	531,373		531,373		590,132
2022
Total	543,678		543,678		330,576
2021
Total	306,525		306,525		341,218
2020
Total	292,198		292,198		272,126
Prior
Total	774,293		774,293		598,838
Revolving Loans Amortized Cost Basis
Total	1,380,049		1,380,049		1,443,203
Total
Total	4,163,489		4,163,489		4,213,215
Portfolio Segment and Loan Class | Commercial and Industrial | Special Mention
2024
Total	13,034		13,034		7,936
2023
Total	22,505		22,505		9,548
2022
Total	53,936		53,936		16,499
2021
Total	45,068		45,068		3,577
2020
Total	24,550		24,550		6,817
Prior
Total	110,455		110,455		18,487
Revolving Loans Amortized Cost Basis
Total	151,806		151,806		72,775
Total
Total	425,173		425,173		135,837
Portfolio Segment and Loan Class | Commercial and Industrial | Substandard or Lower
2024
Total	9,376		9,376		247
2023
Total	15,655		15,655		25,184
2022
Total	39,900		39,900		4,611
2021
Total	6,775		6,775		3,843
2020
Total	8,044		8,044		18,988
Prior
Total	56,206		56,206		31,663
Revolving Loans Amortized Cost Basis
Total	168,937		168,937		105,230
Total
Total	326,072		326,072		196,500
Portfolio Segment and Loan Class | Real estate - construction(1)
2024
Total	138,942		138,942		322,922
Current period gross charge-offs			0		0
2023
Total	445,068		445,068		271,223
Current period gross charge-offs			0		0
2022
Total	306,857		306,857		289,710
Current period gross charge-offs			0		0
2021
Total	121,396		121,396		37,426
Current period gross charge-offs			0		0
2020
Total	9,420		9,420		9,850
Current period gross charge-offs			0		0
Prior
Total	66,049		66,049		55,381
Current period gross charge-offs			0		0
Revolving Loans Amortized Cost Basis
Total	33,535		33,535		13,845
Current period gross charge-offs			0		0
Total
Total	1,121,267		1,121,267		1,002,586
Current period gross charge-offs			0		0
Portfolio Segment and Loan Class | Real estate - construction(1) | Pass
2024
Total	138,942		138,942		322,922
2023
Total	430,449		430,449		258,080
2022
Total	203,827		203,827		261,583
2021
Total	51,226		51,226		37,426
2020
Total	6,138		6,138		9,510
Prior
Total	43,116		43,116		34,097
Revolving Loans Amortized Cost Basis
Total	31,078		31,078		13,677
Total
Total	904,776		904,776		937,295
Portfolio Segment and Loan Class | Real estate - construction(1) | Special Mention
2024
Total	0		0		0
2023
Total	14,619		14,619		12,622
2022
Total	87,643		87,643		25,898
2021
Total	65,668		65,668		0
2020
Total	3,282		3,282		0
Prior
Total	527		527		0
Revolving Loans Amortized Cost Basis
Total	2,324		2,324		0
Total
Total	174,063		174,063		38,520
Portfolio Segment and Loan Class | Real estate - construction(1) | Substandard or Lower
2024
Total	0		0		0
2023
Total	0		0		521
2022
Total	15,387		15,387		2,229
2021
Total	4,502		4,502		0
2020
Total	0		0		340
Prior
Total	22,406		22,406		21,284
Revolving Loans Amortized Cost Basis
Total	133		133		168
Total
Total	42,428		42,428		26,771
Payment Activity, Aging Status
2024
Total	707,645		707,645		1,189,985
2023
Total	1,054,565		1,054,565		1,583,817
2022
Total	1,858,552		1,858,552		1,815,951
2021
Total	1,846,846		1,846,846		1,074,318
2020
Total	1,110,247		1,110,247		320,549
Prior
Total	1,142,704		1,142,704		861,819
Revolving Loans Amortized Cost Basis
Total	901,504		901,504		807,084
Total
Total	8,646,595		8,646,595		7,675,228
Payment Activity, Aging Status | Performing
2024
Total	707,639		707,639		1,189,690
2023
Total	1,053,098		1,053,098		1,579,989
2022
Total	1,851,800		1,851,800		1,810,197
2021
Total	1,841,067		1,841,067		1,069,335
2020
Total	1,106,417		1,106,417		313,962
Prior
Total	1,098,741		1,098,741		821,913
Revolving Loans Amortized Cost Basis
Total	899,502		899,502		805,645
Total
Total	8,580,703		8,580,703		7,610,775
Payment Activity, Aging Status | Nonperforming
2024
Total	6		6		295
2023
Total	1,467		1,467		3,828
2022
Total	6,752		6,752		5,754
2021
Total	5,779		5,779		4,983
2020
Total	3,830		3,830		6,587
Prior
Total	43,963		43,963		39,906
Revolving Loans Amortized Cost Basis
Total	2,002		2,002		1,439
Total
Total	65,892		65,892		64,453
Payment Activity, Aging Status | Real estate - residential mortgage
2024
Total	341,970		341,970		623,247
Current period gross charge-offs			0		0
2023
Total	727,334		727,334		1,128,376
Current period gross charge-offs			(161)		0
2022
Total	1,535,094		1,535,094		1,687,647
Current period gross charge-offs			(62)		0
2021
Total	1,752,976		1,752,976		988,751
Current period gross charge-offs			(12)		0
2020
Total	1,045,304		1,045,304		266,282
Current period gross charge-offs			(43)		0
Prior
Total	899,946		899,946		631,620
Current period gross charge-offs			(888)		0
Revolving Loans Amortized Cost Basis
Total	0		0		0
Current period gross charge-offs			0		0
Total
Total	6,302,624		6,302,624		5,325,923
Current period gross charge-offs			(1,417)		(62)
Payment Activity, Aging Status | Real estate - residential mortgage | Performing
2024
Total	341,970		341,970		623,247
2023
Total	726,077		726,077		1,126,656
2022
Total	1,531,033		1,531,033		1,682,759
2021
Total	1,748,485		1,748,485		984,050
2020
Total	1,041,766		1,041,766		260,049
Prior
Total	871,564		871,564		607,133
Revolving Loans Amortized Cost Basis
Total	0		0		0
Total
Total	6,260,895		6,260,895		5,283,894
Payment Activity, Aging Status | Real estate - residential mortgage | Nonperforming
2024
Total	0		0		0
2023
Total	1,257		1,257		1,720
2022
Total	4,061		4,061		4,888
2021
Total	4,491		4,491		4,701
2020
Total	3,538		3,538		6,233
Prior
Total	28,382		28,382		24,487
Revolving Loans Amortized Cost Basis
Total	0		0		0
Total
Total	41,729		41,729		42,029
Payment Activity, Aging Status | Consumer and Home Equity
2024
Total	170,372		170,372		272,866
Current period gross charge-offs			(77)		(119)
2023
Total	124,641		124,641		276,828
Current period gross charge-offs			(627)		0
2022
Total	232,309		232,309		86,851
Current period gross charge-offs			(1,240)		0
2021
Total	71,422		71,422		62,708
Current period gross charge-offs			(432)		0
2020
Total	51,738		51,738		38,021
Current period gross charge-offs			(292)		0
Prior
Total	219,601		219,601		210,439
Current period gross charge-offs			(1,804)		(525)
Revolving Loans Amortized Cost Basis
Total	901,504		901,504		807,084
Current period gross charge-offs			(3)		(283)
Total
Total	1,796,119		1,796,119		1,776,502
Current period gross charge-offs			(6,312)		(7,514)
Payment Activity, Aging Status | Consumer and Home Equity | Performing
2024
Total	170,366		170,366		272,571
2023
Total	124,431		124,431		276,373
2022
Total	231,555		231,555		85,985
2021
Total	70,197		70,197		62,426
2020
Total	51,484		51,484		37,667
Prior
Total	213,316		213,316		204,913
Revolving Loans Amortized Cost Basis
Total	899,502		899,502		805,645
Total
Total	1,783,290		1,783,290		1,765,624
Payment Activity, Aging Status | Consumer and Home Equity | Nonperforming
2024
Total	6		6		295
2023
Total	210		210		455
2022
Total	754		754		866
2021
Total	1,225		1,225		282
2020
Total	254		254		354
Prior
Total	6,285		6,285		5,526
Revolving Loans Amortized Cost Basis
Total	2,002		2,002		1,439
Total
Total	12,829		12,829		10,878
Payment Activity, Aging Status | Construction - other
2024
Total	84,451		84,451		127,382
Current period gross charge-offs			0		0
2023
Total	100,710		100,710		94,854
Current period gross charge-offs			0		0
2022
Total	24,170		24,170		13,698
Current period gross charge-offs			0		0
2021
Total	2,356		2,356		555
Current period gross charge-offs			0		0
2020
Total	0		0		0
Current period gross charge-offs			0		0
Prior
Total	0		0		0
Current period gross charge-offs			0		0
Revolving Loans Amortized Cost Basis
Total	0		0		0
Current period gross charge-offs			0		0
Total
Total	211,687		211,687		236,489
Current period gross charge-offs			0		0
Payment Activity, Aging Status | Construction - other | Performing
2024
Total	84,451		84,451		127,382
2023
Total	100,710		100,710		93,319
2022
Total	22,764		22,764		13,698
2021
Total	2,356		2,356		555
2020
Total	0		0		0
Prior
Total	0		0		0
Revolving Loans Amortized Cost Basis
Total	0		0		0
Total
Total	210,281		210,281		234,954
Payment Activity, Aging Status | Construction - other | Nonperforming
2024
Total	0		0		0
2023
Total	0		0		1,535
2022
Total	1,406		1,406		0
2021
Total	0		0		0
2020
Total	0		0		0
Prior
Total	0		0		0
Revolving Loans Amortized Cost Basis
Total	0		0		0
Total
Total	1,406		1,406		1,535
Payment Activity, Aging Status | Leases and other loans
2024
Total	110,852		110,852		166,490
Current period gross charge-offs			(830)		(471)
2023
Total	101,880		101,880		83,759
Current period gross charge-offs			(694)		(521)
2022
Total	66,979		66,979		27,755
Current period gross charge-offs			(222)		(246)
2021
Total	20,092		20,092		22,304
Current period gross charge-offs			(237)		(128)
2020
Total	13,205		13,205		16,246
Current period gross charge-offs			(125)		(82)
Prior
Total	23,157		23,157		19,760
Current period gross charge-offs			(510)		(656)
Revolving Loans Amortized Cost Basis
Total	0		0		0
Current period gross charge-offs			(135)		(765)
Total
Total	336,165		336,165		336,314
Current period gross charge-offs			(2,929)		(4,380)
Payment Activity, Aging Status | Leases and other loans | Performing
2024
Total	110,852		110,852		166,490
2023
Total	101,880		101,880		83,641
2022
Total	66,448		66,448		27,755
2021
Total	20,029		20,029		22,304
2020
Total	13,167		13,167		16,246
Prior
Total	13,861		13,861		9,867
Revolving Loans Amortized Cost Basis
Total	0		0		0
Total
Total	326,237		326,237		326,303
Payment Activity, Aging Status | Leases and other loans | Nonperforming
2024
Total	0		0		0
2023
Total	0		0		118
2022
Total	531		531		0
2021
Total	63		63		0
2020
Total	38		38		0
Prior
Total	9,296		9,296		9,893
Revolving Loans Amortized Cost Basis
Total	0		0		0
Total
Total	9,928		9,928		10,011
Conversion to Term Loan | Portfolio Segment and Loan Class
Revolving Loans Amortized Cost Basis
Total	31,523		31,523		51,533
Conversion to Term Loan | Portfolio Segment and Loan Class | Pass
Revolving Loans Amortized Cost Basis
Total	6,525		6,525		42,372
Conversion to Term Loan | Portfolio Segment and Loan Class | Special Mention
Revolving Loans Amortized Cost Basis
Total	3,819		3,819		198
Conversion to Term Loan | Portfolio Segment and Loan Class | Substandard or Lower
Revolving Loans Amortized Cost Basis
Total	21,179		21,179		8,963
Conversion to Term Loan | Portfolio Segment and Loan Class | Real estate - commercial mortgage
Revolving Loans Amortized Cost Basis
Total	324		324		31,636
Current period gross charge-offs			(26)		(17,575)
Conversion to Term Loan | Portfolio Segment and Loan Class | Real estate - commercial mortgage | Pass
Revolving Loans Amortized Cost Basis
Total	324		324		31,636
Conversion to Term Loan | Portfolio Segment and Loan Class | Real estate - commercial mortgage | Special Mention
Revolving Loans Amortized Cost Basis
Total	0		0		0
Conversion to Term Loan | Portfolio Segment and Loan Class | Real estate - commercial mortgage | Substandard or Lower
Revolving Loans Amortized Cost Basis
Total	0		0		0
Conversion to Term Loan | Portfolio Segment and Loan Class | Commercial and Industrial
Revolving Loans Amortized Cost Basis
Total	31,199		31,199		17,668
Current period gross charge-offs			(3,635)		(8,016)
Conversion to Term Loan | Portfolio Segment and Loan Class | Commercial and Industrial | Pass
Revolving Loans Amortized Cost Basis
Total	6,201		6,201		10,736
Conversion to Term Loan | Portfolio Segment and Loan Class | Commercial and Industrial | Special Mention
Revolving Loans Amortized Cost Basis
Total	3,819		3,819		198
Conversion to Term Loan | Portfolio Segment and Loan Class | Commercial and Industrial | Substandard or Lower
Revolving Loans Amortized Cost Basis
Total	21,179		21,179		6,734
Conversion to Term Loan | Portfolio Segment and Loan Class | Real estate - construction(1)
Revolving Loans Amortized Cost Basis
Total	0		0		2,229
Current period gross charge-offs			0		0
Conversion to Term Loan | Portfolio Segment and Loan Class | Real estate - construction(1) | Pass
Revolving Loans Amortized Cost Basis
Total	0		0		0
Conversion to Term Loan | Portfolio Segment and Loan Class | Real estate - construction(1) | Special Mention
Revolving Loans Amortized Cost Basis
Total	0		0		0
Conversion to Term Loan | Portfolio Segment and Loan Class | Real estate - construction(1) | Substandard or Lower
Revolving Loans Amortized Cost Basis
Total	0		0		2,229
Conversion to Term Loan | Payment Activity, Aging Status
Revolving Loans Amortized Cost Basis
Total	24,532		24,532		21,705
Conversion to Term Loan | Payment Activity, Aging Status | Performing
Revolving Loans Amortized Cost Basis
Total	22,439		22,439		20,044
Conversion to Term Loan | Payment Activity, Aging Status | Nonperforming
Revolving Loans Amortized Cost Basis
Total	2,093		2,093		1,661
Conversion to Term Loan | Payment Activity, Aging Status | Real estate - residential mortgage
Revolving Loans Amortized Cost Basis
Total	0		0		0
Current period gross charge-offs			(251)		(62)
Conversion to Term Loan | Payment Activity, Aging Status | Real estate - residential mortgage | Performing
Revolving Loans Amortized Cost Basis
Total	0		0		0
Conversion to Term Loan | Payment Activity, Aging Status | Real estate - residential mortgage | Nonperforming
Revolving Loans Amortized Cost Basis
Total	0		0		0
Conversion to Term Loan | Payment Activity, Aging Status | Consumer and Home Equity
Revolving Loans Amortized Cost Basis
Total	24,532		24,532		21,705
Current period gross charge-offs			(1,837)		(6,587)
Conversion to Term Loan | Payment Activity, Aging Status | Consumer and Home Equity | Performing
Revolving Loans Amortized Cost Basis
Total	22,439		22,439		20,044
Conversion to Term Loan | Payment Activity, Aging Status | Consumer and Home Equity | Nonperforming
Revolving Loans Amortized Cost Basis
Total	2,093		2,093		1,661
Conversion to Term Loan | Payment Activity, Aging Status | Construction - other
Revolving Loans Amortized Cost Basis
Total	0		0		0
Current period gross charge-offs			0		0
Conversion to Term Loan | Payment Activity, Aging Status | Construction - other | Performing
Revolving Loans Amortized Cost Basis
Total	0		0		0
Conversion to Term Loan | Payment Activity, Aging Status | Construction - other | Nonperforming
Revolving Loans Amortized Cost Basis
Total	0		0		0
Conversion to Term Loan | Payment Activity, Aging Status | Leases and other loans
Revolving Loans Amortized Cost Basis
Total	0		0		0
Current period gross charge-offs			(176)		(1,511)
Conversion to Term Loan | Payment Activity, Aging Status | Leases and other loans | Performing
Revolving Loans Amortized Cost Basis
Total	0		0		0
Conversion to Term Loan | Payment Activity, Aging Status | Leases and other loans | Nonperforming
Revolving Loans Amortized Cost Basis
Total	$ 0		$ 0		$ 0