REVENUE RECOGNITION - Summary of Noninterest Income (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	$ 859		$ 1,122	$ 1,624	$ 2,288
Noninterest income (out-of-scope of Topic 606)	4,669		(3,412)	5,965	1,717
Total noninterest income (loss)	5,528	$ 2,061	(2,290)	7,589	4,005
Deposit service fees
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	420		575	959	1,242
Debit card fees
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	380		178	557	291
Investment commissions
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	0		260	0	539
Other
Disaggregation of Revenue [Line Items]
Noninterest income (in-scope of Topic 606)	$ 59		$ 109	$ 108	$ 216