DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Schedule of Net Gains (Losses) Relating to Free-Standing Derivative Instruments (Details) - Mortgage Banking Activity - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Forward contracts related to mortgage loans held for sale
Derivative [Line Items]
Gain (loss) on derivative instruments, net, pretax, total	$ (12)	$ 1,285	$ (137)
Interest rate lock commitments
Derivative [Line Items]
Gain (loss) on derivative instruments, net, pretax, total	$ 2,833	$ 3,029	$ 2,687

Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5618551-113959

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration