GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Identifiable Intangible Assets
Gross Carrying Amount	$ 203,292	$ 197,186
Accumulated Amortization	(150,701)	(136,190)
Net Carrying Amount	52,591	60,996
Estimated aggregate amortization expense for each of five succeeding fiscal years
2024	12,856
2025	10,969
2026	9,662
2027	4,079
2026	3,011
Thereafter	12,014
Net Carrying Amount	52,591	60,996
Components of goodwill
Goodwill, beginning of period	841,841	799,109
Goodwill, net, beginning of period	841,841	799,109
Goodwill Additions	3,555	42,732
Goodwill, end of period	845,396	841,841
Goodwill, net, end of period	845,396	841,841
Total principal balance of loans	532,900	583,100
Total custodial escrow balances maintained in connection with loans	10,200	10,500
Impairment loss for goodwill		0
Core deposit intangibles
Identifiable Intangible Assets
Gross Carrying Amount	77,373	77,373
Accumulated Amortization	(69,214)	(65,069)
Net Carrying Amount	8,159	12,304
Estimated aggregate amortization expense for each of five succeeding fiscal years
Net Carrying Amount	8,159	12,304
Other intangibles
Identifiable Intangible Assets
Gross Carrying Amount	125,919	119,813
Accumulated Amortization	(81,487)	(71,121)
Net Carrying Amount	44,432	48,692
Estimated aggregate amortization expense for each of five succeeding fiscal years
Net Carrying Amount	$ 44,432	$ 48,692