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PORTFOLIO LOANS - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net deferred loan origination costs	$ 8,800,000		$ 8,800,000		$ 12,500,000
Net accretable purchase accounting adjustments			(92,000,000)		(8,800,000)
Amount of interest collected and recognized on a cash basis	0	$ 0	0	$ 0
Commitment to lend	400,000		400,000		0
Collateral dependent loans secured by real estate or business assets	39,000,000		39,000,000		$ 19,300,000
Loans in the process of foreclosure	6,100,000		6,100,000
CrossFirst
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCD loans acquired and fully reserved at acquisition			35,500,000
90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross interest income that would have been recorded if impaired loans had been current	900,000	100,000	2,100,000	600,000
Retail loans | CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans purchased	$ 0	$ 0	0	$ 6,900,000
Commercial loans | Watch
Accounts, Notes, Loans and Financing Receivable [Line Items]
Limit above which loans are annually reviewed			2,000,000
Commercial loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Limit above which loans are annually reviewed			350,000
Commercial loans | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Limit where loans are processed through an expedited underwriting process			$ 2,000,000

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