DUE TO DEPOSITORS (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deposits Liability [Abstract]
Savings accounts	$ 336,669	$ 362,092
Certificates of deposit ("CDs")	1,410,037	1,091,887
Money market accounts	2,098,599	2,517,439
Interest bearing checking accounts	115,972	124,283
Non-interest bearing checking accounts	395,477	307,746
Due to depositors	$ 4,356,754	$ 4,403,447
Weighted Average Rate Domestic Deposits Liability [Abstract]
Savings accounts	0.06%	0.07%
Certificates of deposit ("CDs")	1.97%	1.47%
Money market accounts	1.43%	0.96%
Interest bearing checking accounts	0.30%	0.08%
Non-interest bearing checking accounts	0.00%	0.00%
TOTAL	1.33%	0.91%
Maturities of Time Deposits [Abstract]
2019	$ 1,033,224
2020	276,966
2021	34,639
2022	50,869
2023	9,492
2024 and beyond	4,847
TOTAL	$ 1,410,037
Weighted Average Rate of Time Deposits [Abstract]
2019	1.95%
2020	1.98%
2021	1.97%
2022	2.38%
2023	1.95%
2024 and beyond	1.59%
TOTAL	1.97%
Aggregate amount of CDs $250,000 or More	$ 287,834	$ 179,307