COMMITMENTS AND CONTINGENCIES - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Commitments and Contingencies Disclosure [Line Items]
Reserves for unfunded commitments	$ 20,200		$ 18,400
Loans and Leases Receivable, Commitments, Fixed Rates	111,100		126,300
Loans and Leases Receivable, Commitments, Variable Rates	$ 4,500,000		$ 4,200,000
Loan Commitments, Fixed Interest Rate Range, Minimum	0.00%		0.00%
Loan Commitments, Fixed Interest Rate Range, Maximum	21.00%		21.00%
Loan Commitments, Fixed Rate, Maturities, Minimum	1 year		1 year
Loan Commitments, Fixed Rate, Maturities, Maximum	31 years		31 years 7 months 6 days
Letters of credit issued to guarantee performance of a client to a third party	$ 32,200		$ 31,500
Derivative, Notional Amount	20,305,538		19,828,103
Litigation Settlement, Expense	0	$ 3,300
Estimated Litigation Liability	0		0
Credit Default Swap
Commitments and Contingencies Disclosure [Line Items]
Derivative, Notional Amount	386,800		379,300
Commitments to Extend Credit
Commitments and Contingencies Disclosure [Line Items]
Commitments outstanding to extend credit	$ 4,600,000		$ 4,400,000