INVESTMENT SECURITIES - Schedule of Investment Securities Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Amortized Cost
Less than one year	$ 10,000
One to five years	30,000
Five to ten years	3,777
Beyond ten years	12,281
Amortized Cost	638,386	$ 623,037
Fair Value
Less than one year	10,018
One to five years	29,987
Five to ten years	3,781
Beyond ten years	12,331
Fair Value	641,474	625,074
Amortized Cost
Held-to-maturity investment securities beyond ten years	81
Amortized Cost	9,732	10,170
Fair Value
Beyond ten years	81
Total held to maturity debt securities	10,132	$ 10,349
MBS and CMOs
Amortized Cost
MBS and CMOs	582,328
Fair Value
MBS and CMOs	585,357
MBS
Amortized Cost
MBS	9,651
Fair Value
MBS	$ 10,051