Loans and Allowance for Credit Losses on Loans - Allowance Activity (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 271,709	$ 249,973	$ 249,973
Provision for credit losses on loans	38,819	49,393
Charge-offs	37,942	29,389	46,055
Recoveries	1,440	587
Net charge-offs (recoveries)	36,502	28,802
Ending balance	274,026	273,143	271,709
Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	198,423	171,437	171,437
Provision for credit losses on loans	35,106	54,529
Charge-offs	37,011	23,661
Recoveries	1,019	587
Net charge-offs (recoveries)	35,992	23,074
Ending balance	197,537	205,471	198,423
Mortgage finance
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	2,755	4,173	4,173
Provision for credit losses on loans	5,944	1,290
Charge-offs	0	0
Recoveries	0	0
Net charge-offs (recoveries)	0	0
Ending balance	8,699	5,463	2,755
Commercial real estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	68,825	71,829	71,829
Provision for credit losses on loans	(2,306)	(6,840)
Charge-offs	931	5,698
Recoveries	413	0
Net charge-offs (recoveries)	518	5,698
Ending balance	66,001	59,291	68,825
Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,706	2,534	2,534
Provision for credit losses on loans	75	414
Charge-offs	0	30
Recoveries	8	0
Net charge-offs (recoveries)	(8)	30
Ending balance	$ 1,789	$ 2,918	$ 1,706

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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- 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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- Definition

Amount, excluding accrued interest, of increase (decrease) in 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 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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- Definition

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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- 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 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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-Publisher FASB
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- Definition

Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. 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 (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476148/220-40-50-22

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