FAIR VALUES - Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Corporate bonds and notes
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance of recurring Level 3 assets at January 1	$ 0	$ 0
Derivative instruments entered into	0	0
Total gains or losses for the period:
Included in earnings - other non-interest income	0	0
Balance of recurring Level 3 assets at December 31	0	0
Derivative liabilities
Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance of recurring Level 3 assets at January 1	(140)	(75)
Derivative instruments entered into	(43)	(1)
Included in earnings - other non-interest income	(182)	(64)
Balance of recurring Level 3 assets at December 31	$ (365)	$ (140)