INVESTMENT SECURITIES - PLEDGED DEBT SECURITIES (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
INVESTMENT SECURITIES
Carrying value	$ 257,934	$ 262,679
Fair value	$ 258,250	$ 262,902

The carrying amount of securities categorized as held-to-maturity which serve as security for borrowings or other arrangements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 320
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-12)
-URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611133-123010

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5086-111524

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(f))
-URI http://asc.fasb.org/extlink&oid=6488002&loc=d3e600178-122990

Name:	us-gaap_HeldToMaturitySecuritiesRestricted
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant