PORTFOLIO LOANS - Narrative (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net deferred loan origination costs	$ 12,300,000		$ 12,500,000
Net accretable purchase accounting adjustments	(105,300,000)		(8,800,000)
Amount of interest collected and recognized on a cash basis	0	$ 0
Collateral dependent loans secured by real estate or business assets	45,100,000		$ 19,300,000
Loans in the process of foreclosure	5,700,000
CrossFirst
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCD loans acquired and fully reserved at acquisition	29,600,000
90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross interest income that would have been recorded if impaired loans had been current	200,000	300,000
Retail loans | CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans purchased	0	$ 0
Commercial loans | Watch
Accounts, Notes, Loans and Financing Receivable [Line Items]
Limit above which loans are annually reviewed	1,000,000
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	$ 1,000,000