LOANS AND ALLOWANCE FOR LOAN AND LEASE LOSSES (Loans Stated at Face Amount, Net of Unearned Income) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Loans and Leases Receivable Disclosure [Line Items]
LHFI, net of deferred fees and costs	$ 15,851,628	$ 15,635,043
Total Allowance for credit losses	(136,190)	(132,182)	$ (116,512)	$ (110,768)
Total loans held for investment, net	15,715,438	15,502,861
Loans receivable, deferred fees and costs	92,500	79,700
Construction and Land Development
Loans and Leases Receivable Disclosure [Line Items]
LHFI, net of deferred fees and costs	1,246,251	1,107,850
Commercial Real Estate - Owner Occupied
Loans and Leases Receivable Disclosure [Line Items]
LHFI, net of deferred fees and costs	1,981,613	1,998,787
Commercial Real Estate - Non-Owner Occupied
Loans and Leases Receivable Disclosure [Line Items]
LHFI, net of deferred fees and costs	4,225,018	4,172,401
Multifamily Real Estate
Loans and Leases Receivable Disclosure [Line Items]
LHFI, net of deferred fees and costs	1,074,957	1,061,997
Commercial and Industrial
Loans and Leases Receivable Disclosure [Line Items]
LHFI, net of deferred fees and costs	3,561,971	3,589,347
Residential 1-4 Family - Commercial
Loans and Leases Receivable Disclosure [Line Items]
LHFI, net of deferred fees and costs	515,667	522,580
Residential 1-4 Family - Mortgage
Loans and Leases Receivable Disclosure [Line Items]
LHFI, net of deferred fees and costs	1,081,094	1,078,173
Residential 1-4 Family - Revolving
Loans and Leases Receivable Disclosure [Line Items]
LHFI, net of deferred fees and costs	616,951	619,433
Auto
Loans and Leases Receivable Disclosure [Line Items]
LHFI, net of deferred fees and costs	440,118	486,926
Consumer
Loans and Leases Receivable Disclosure [Line Items]
LHFI, net of deferred fees and costs	113,414	120,641
Other Commercial
Loans and Leases Receivable Disclosure [Line Items]
LHFI, net of deferred fees and costs	$ 994,574	$ 876,908