FAIR VALUES FAIR VALUES - Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Corporate bonds and notes
Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance of recurring Level 3 assets at January 1	$ 250	$ 248
Derivative instruments entered into	0	0
Included in earnings - other non-interest income	0	0
Included in other comprehensive income	1	2
Transfers out of Level 3	(251)	0
Balance of recurring Level 3 assets at December 31	0	250
Derivative liabilities
Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance of recurring Level 3 assets at January 1	(68)	(48)
Derivative instruments entered into	(5)	(25)
Included in earnings - other non-interest income	(2)	5
Included in other comprehensive income	0	0
Transfers out of Level 3	0	0
Balance of recurring Level 3 assets at December 31	$ (75)	$ (68)