Loans - Allowance for Loan Losses by Portfolio Segment (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
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 100,865	$ 94,353	$ 96,868	$ 87,161	$ 87,161
Charge-offs	11,226	3,202	21,615	8,246
Recoveries	1,706	516	6,567	2,330
Provision	4,644	3,510	14,169	13,932
Ending balance	95,989	95,177	95,989	95,177	96,868
Average balance	$ 7,930,996	$ 7,561,094	$ 7,872,235	$ 7,395,440
Net charge-offs to loan average balance (annualized)	0.48%	0.14%	0.26%	0.11%
Provision for credit losses	$ 4,600	$ 3,500	$ 12,800	$ 14,000
Provision for loan credit losses	4,644	3,510	14,169	13,932
Provision (benefit) for off-balance sheet commitments	(36)	50	(1,300)	95
Provision (benefit) for held to maturity securities	(5)	(45)	(11)	(9)
Real Estate \| Commercial Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	17,244	20,839	19,625	19,772	19,772
Charge-offs	0	0	480	42	42
Recoveries	21	28	318	113
Provision	(435)	(1,758)	(2,633)	(734)
Ending balance	16,830	19,109	16,830	19,109	19,625
Average balance	$ 2,507,566	$ 2,428,969	$ 2,481,274	$ 2,393,028
Net charge-offs to loan average balance (annualized)	0.00%	0.00%	0.01%	0.00%
Provision for loan credit losses	$ (435)	$ (1,758)	$ (2,633)	$ (734)
Real Estate \| Construction/ Land/ Land Development
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	9,274	8,729	9,990	7,776	7,776
Charge-offs	0	0	0	0	0
Recoveries	0	3	0	3
Provision	(546)	613	(1,262)	1,566
Ending balance	8,728	9,345	8,728	9,345	9,990
Average balance	$ 1,019,302	$ 1,044,180	$ 1,069,360	$ 997,296
Net charge-offs to loan average balance (annualized)	0.00%	0.00%	0.00%	0.00%
Provision for loan credit losses	$ (546)	$ 613	$ (1,262)	$ 1,566
Real Estate \| Residential Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	11,780	9,018	10,619	8,230	8,230
Charge-offs	11	0	11	27	27
Recoveries	4	3	12	13
Provision	302	1,048	1,455	1,853
Ending balance	12,075	10,069	12,075	10,069	10,619
Average balance	$ 1,824,725	$ 1,663,291	$ 1,784,035	$ 1,599,803
Net charge-offs to loan average balance (annualized)	0.00%	0.00%	0.00%	0.00%
Provision for loan credit losses	$ 302	$ 1,048	$ 1,455	$ 1,853
Commercial and industrial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	61,184	54,173	55,330	50,148	50,148
Charge-offs	11,195	3,187	21,044	8,070	11,833
Recoveries	1,680	477	6,228	2,189
Provision	5,070	3,990	16,225	11,186
Ending balance	56,739	55,453	56,739	55,453	55,330
Average balance	$ 2,071,984	$ 2,024,675	$ 2,107,195	$ 2,051,272
Net charge-offs to loan average balance (annualized)	1.83%	0.53%	0.94%	0.38%
Provision for loan credit losses	$ 5,070	$ 3,990	$ 16,225	$ 11,186
Mortgage Warehouse Lines of Credit
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	676	817	529	379	379
Charge-offs	0	0	0	0	0
Recoveries	0	0	0	0
Provision	(13)	(359)	134	79
Ending balance	663	458	663	458	529
Average balance	$ 484,680	$ 376,275	$ 407,553	$ 329,205
Net charge-offs to loan average balance (annualized)	0.00%	0.00%	0.00%	0.00%
Provision for loan credit losses	$ (13)	$ (359)	$ 134	$ 79
Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	707	777	775	856	856
Charge-offs	20	15	80	107	147
Recoveries	1	5	9	12
Provision	266	(24)	250	(18)
Ending balance	954	743	954	743	$ 775
Average balance	$ 22,739	$ 23,704	$ 22,818	$ 24,836
Net charge-offs to loan average balance (annualized)	0.33%	0.17%	0.42%	0.51%
Provision for loan credit losses	$ 266	$ (24)	$ 250	$ (18)

Credit Loss, Expense (Reversal)

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Percentage of writeoff after recovery to average financing receivables outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph a
-Subparagraph (4)
-Publisher SEC

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount, excluding accrued interest, of credit loss expense (reversal of expense) on investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

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Amount, excluding accrued interest, of increase in allowance for credit loss on financing receivable from recovery. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6

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Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease.

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Average amount outstanding, before allowance for credit loss, of financing receivables.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Number 229
-Section 1402
-Paragraph a
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Number 229
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Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

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