DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Schedule of Interest Rate Swap Agreements and Non-hedging Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Offsetting Assets [Line Items]
Notional Amount	$ 4,524,514	$ 3,711,905
Estimated Fair Value Asset (Liability)	(43,167)	43,426
Fair value estimates, impact of settled to market contract	38,300	45,700
Economic hedges: \| Interest rate swap \| Tax advantaged economic development bonds
Offsetting Assets [Line Items]
Notional Amount	7,100
Cash Flow Hedging
Offsetting Assets [Line Items]
Notional Amount	800,000
Estimated Fair Value Asset (Liability)	1,937
Cash Flow Hedging \| Interest rate swap \| Commercial Loan
Offsetting Assets [Line Items]
Notional Amount	$ 400,000
Weighted Average Maturity (in years)	2 years 8 months 12 days
Weighted Average Rate - Received	4.09%
Weighted Average Rate - Contract pay rate	3.51%
Estimated Fair Value Asset (Liability)	$ 0
Cash Flow Hedging \| Forward Starting Interest Rate Swaps \| Commercial Loan
Offsetting Assets [Line Items]
Notional Amount	$ 200,000
Weighted Average Maturity (in years)	3 years 3 months 18 days
Weighted Average Rate - Received	0.00%
Weighted Average Rate - Contract pay rate	3.90%
Estimated Fair Value Asset (Liability)	$ 0
Cash Flow Hedging \| Interest Rate Collars \| Commercial Loan
Offsetting Assets [Line Items]
Notional Amount	$ 200,000
Weighted Average Maturity (in years)	3 years 6 months
Estimated Fair Value Asset (Liability)	$ 1,937
Hedging derivatives \| Economic hedges:
Offsetting Assets [Line Items]
Notional Amount	3,720,400	3,703,713
Estimated Fair Value Asset (Liability)	(45,121)	43,302
Hedging derivatives \| Economic hedges: \| Interest rate swap
Offsetting Assets [Line Items]
Notional Amount	3,400,000
Hedging derivatives \| Economic hedges: \| Interest rate swap \| Tax advantaged economic development bonds
Offsetting Assets [Line Items]
Notional Amount	$ 7,062	$ 7,879
Weighted Average Maturity (in years)	6 years 10 months 24 days	7 years 10 months 24 days
Weighted Average Rate - Received	4.49%	0.47%
Weighted Average Rate - Contract pay rate	5.09%	5.09%
Estimated Fair Value Asset (Liability)	$ (193)	$ (1,158)
Hedging derivatives \| Economic hedges: \| Interest rate swap \| Commercial loan
Offsetting Assets [Line Items]
Notional Amount	$ 1,685,263	$ 1,684,238
Weighted Average Maturity (in years)	5 years 8 months 12 days	5 years 9 months 18 days
Weighted Average Rate - Received	4.11%	3.99%
Weighted Average Rate - Contract pay rate	5.55%	1.91%
Estimated Fair Value Asset (Liability)	$ (95,114)	$ 74,348
Hedging derivatives \| Economic hedges: \| Reverse interest rate swaps \| Commercial loan
Offsetting Assets [Line Items]
Notional Amount	$ 1,685,263	$ 1,684,238
Weighted Average Maturity (in years)	5 years 8 months 12 days	5 years 9 months 18 days
Weighted Average Rate - Received	5.55%	1.91%
Weighted Average Rate - Contract pay rate	4.11%	3.99%
Estimated Fair Value Asset (Liability)	$ 50,267	$ (30,454)
Hedging derivatives \| Economic hedges: \| Risk participation agreements
Offsetting Assets [Line Items]
Notional Amount	$ 341,885	$ 320,981
Weighted Average Maturity (in years)	6 years 7 months 6 days	5 years 9 months 18 days
Estimated Fair Value Asset (Liability)	$ (89)	$ 432
Hedging derivatives \| Economic hedges: \| Forward Sale commitments
Offsetting Assets [Line Items]
Notional Amount	$ 927	$ 6,377
Weighted Average Maturity (in years)	2 months 12 days	2 months 12 days
Estimated Fair Value Asset (Liability)	$ 8	$ 134
Hedging derivatives \| Cash Flow Hedging \| Interest rate swap
Offsetting Assets [Line Items]
Notional Amount	600,000
Hedging derivatives \| Cash Flow Hedging \| Interest Rate Collars
Offsetting Assets [Line Items]
Notional Amount	200,000
Non-hedging derivatives:
Offsetting Assets [Line Items]
Notional Amount	4,114	8,192
Estimated Fair Value Asset (Liability)	17	124
Non-hedging derivatives: \| Commitments to Lend
Offsetting Assets [Line Items]
Notional Amount	$ 4,114	$ 8,192
Weighted Average Maturity (in years)	2 months 12 days	2 months 12 days
Estimated Fair Value Asset (Liability)	$ 17	$ 124

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