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- Definition

Restructured Loans, Loan Relationships, Review Threshold Amount Minimum for commercial and other loans greater than $250,000

+ References

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

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- Definition

Amortized cost of financing receivable with payment default in current period and modified within previous 12 months preceding payment default for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition

Carrying amount as of the balance sheet date of land and buildings obtained through foreclosure proceedings or defeasance in full or partial satisfaction of a debt arrangement.

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- Definition

Unused amount of commitments to extend credit to customers.

+ References

No definition available.

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LOANS AND LEASES - Additional Information (Details)	3 Months Ended
LOANS AND LEASES - Additional Information (Details)	Mar. 31, 2026 USD ($) loans	Mar. 31, 2025 USD ($) loans	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	$ 1,000,000.0	$ 1,000,000.0
Real Estate Acquired Through Foreclosure	238,000	$ 213,000	$ 184,000	$ 64,000
Unused Commitments to Extend Credit	$ 4,660,934,000		4,467,728,000
Impaired receivables, Number of Contracts \| loans	6	10
Gross loans and leases, excluding accrued interest	$ 13,494,841,000		13,424,070,000
BankFinancial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans and leases, excluding accrued interest	300,000,000
Commercial segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans and leases, excluding accrued interest	22,576,000		27,461,000
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Restructured Loans, Loan Relationships, Review Threshold Amount Minimum	250,000
Gross loans and leases, excluding accrued interest	17,439,000		18,302,000
Lease financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans and leases, excluding accrued interest	5,857,000		$ 5,660,000
Financial Difficulty Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unused Commitments to Extend Credit	$ 0	$ 0