FEDERAL HOME LOAN BANK ADVANCES - SHORT-TERM FHLB ADVANCES (Details) - Federal Home Loan Bank overnight advances - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
FHLB advances
Average outstanding balance during the period	$ 42,198	$ 448,077	$ 43,681	$ 331,768
Average interest rate during the period (as percent)	0.22%	2.50%	0.92%	2.49%
Maximum outstanding at any month end during the period	$ 165,000	$ 785,000	$ 250,000	$ 785,000