MORTGAGE BANKING ACTIVITIES - OTHER INFORMATION RELATING TO MSRS (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2018	Dec. 31, 2017
MORTGAGE BANKING ACTIVITIES
Fair value of mortgage servicing rights portfolio	$ 8,841	$ 7,984
Monthly weighted average prepayment rate of unpaid principle balance (as percent)	176.00%	200.00%
Discount rate (as percent)	10.00%	10.00%
Weighted average default rate (as percent)	4.08%	3.75%
Weighted average life in years	5 years 11 months 27 days	5 years 5 months 27 days

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- Definition

Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=68078379&loc=d3e122625-111746

+ Details

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- Definition

Discount rate used to estimate the fair value of servicing assets and servicing liabilities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 2
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=68078379&loc=d3e122596-111746

+ Details

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- Definition

Percentage of contractually collectible principal associated with a financial asset expected not to be collected due to default by the borrower.

+ References

+ Details

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- Definition

Estimated rate of prepayments of principal on servicing assets and servicing liabilities.

+ References

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- Definition

Weighted average life of financial assets and financial liabilities, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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