FAIR VALUE - Unobservable Inputs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Corporate bonds and notes
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance of recurring Level 3 assets at beginning of period	$ 0	$ 250
Included in earnings - other non-interest income	0	0
Included in other comprehensive income	0	1
Balance of recurring Level 3 assets at end of period	0	251
Derivative Liabilities
Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance of recurring Level 3 assets at beginning of period	(75)	(68)
Included in earnings - other non-interest income	25	3
Included in other comprehensive income	0	0
Balance of recurring Level 3 assets at end of period	$ (50)	$ (65)