Allowance for Credit Losses - Activity in ACL by Class of Loans and Leases (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	$ 156,533	$ 143,900	$ 143,900
Charge-offs	(5,763)	(5,830)
Recoveries	1,974	2,616
Provision	7,092	6,436
Balance at end of year	159,836	147,122	156,533
Commercial Lending
Rollforward of the Allowance for Credit Losses
Charge-offs	(909)		(5,982)
Commercial and Industrial
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	14,956	14,564	14,564
Charge-offs	(909)	(791)	(3,482)
Recoveries	211	246
Provision	2,829	19
Balance at end of year	17,087	14,038	14,956
Commercial Real Estate
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	43,944	43,810	43,810
Charge-offs			(2,500)
Provision	(418)	(3,499)
Balance at end of year	43,526	40,311	43,944
Construction
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	10,392	5,843	5,843
Provision	2,049	630
Balance at end of year	12,441	6,473	10,392
Lease financing
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	1,754	1,551	1,551
Provision	731	(70)
Balance at end of year	2,485	1,481	1,754
Residential mortgage
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	36,880	35,175	35,175
Charge-offs		(122)	(414)
Recoveries	30	27
Provision	(120)	(760)
Balance at end of year	36,790	34,320	36,880
Residential mortgage \| Residential Lending: Home Equity Line
Rollforward of the Allowance for Credit Losses
Charge-offs			(292)
Residential Lending: Home Equity Line
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	11,728	8,296	8,296
Charge-offs		(135)
Recoveries	44	177
Provision	(325)	1,003
Balance at end of year	11,447	9,341	11,728
Consumer
Rollforward of the Allowance for Credit Losses
Balance at beginning of year	36,879	34,661	34,661
Charge-offs	(4,854)	(4,782)	(17,110)
Recoveries	1,689	2,166
Provision	2,346	9,113
Balance at end of year	$ 36,060	$ 41,158	$ 36,879

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

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- Definition

Amount of increase in allowance for credit loss on financing receivable and net investment in leases from recovery.

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

Amount of increase (decrease) in allowance for credit loss on financing receivable and net investment in leases.

+ References

No definition available.

+ Details

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- Definition

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

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

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