FAIR VALUE OF FINANCIAL INSTRUMENTS - Financial Instruments Not Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Financial Assets [Abstract]
Securities held-to-maturity	$ 532,572	$ 505,759
Carrying Amount
Financial Assets [Abstract]
Cash and due from banks	663,132	169,297
Securities held-to-maturity	605,642	585,798
Loans held for investment, net	10,651,565	10,482,145
Accrued interest receivable	49,926	48,561
Financial Liabilities [Abstract]
Savings, money market and checking accounts	9,050,968	9,139,043
Certificates of Deposits ("CDs")	1,519,267	1,115,364
FHLBNY Advances	1,498,000	1,131,000
Subordinated debt, net	200,261	200,283
Other short-term borrowings	2,068	1,360
Accrued interest payable	12,842	5,323
Fair Value
Financial Assets [Abstract]
Cash and due from banks	663,132	169,297
Securities held-to-maturity	532,572	505,759
Loans held for investment, net	10,123,743	10,005,121
Accrued interest receivable	49,926	48,561
Financial Liabilities [Abstract]
Savings, money market and checking accounts	9,050,968	9,139,043
Certificates of Deposits ("CDs")	1,503,948	1,096,808
FHLBNY Advances	1,502,366	1,131,217
Subordinated debt, net	164,461	180,583
Other short-term borrowings	2,068	1,360
Accrued interest payable	12,842	5,323
Level 1 Inputs | Fair Value
Financial Assets [Abstract]
Cash and due from banks	663,132	169,297
Financial Liabilities [Abstract]
Savings, money market and checking accounts	9,050,968	9,139,043
Other short-term borrowings	2,068	1,360
Level 2 Inputs | Fair Value
Financial Assets [Abstract]
Securities held-to-maturity	532,572	505,759
Accrued interest receivable	5,505	6,105
Financial Liabilities [Abstract]
Certificates of Deposits ("CDs")	1,503,948	1,096,808
FHLBNY Advances	1,502,366	1,131,217
Subordinated debt, net	164,461	180,583
Accrued interest payable	12,842	5,323
Level 3 Inputs | Fair Value
Financial Assets [Abstract]
Loans held for investment, net	10,123,743	10,005,121
Accrued interest receivable	$ 44,421	$ 42,456