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SUBORDINATED DEBENTURES - Narrative (Details)	1 Months Ended	9 Months Ended		12 Months Ended
	May 31, 2017 USD ($)	Sep. 30, 2017 USD ($) trust $ / shares	Sep. 30, 2016 USD ($)	Dec. 31, 2016	Jul. 31, 2017 USD ($)	Dec. 31, 2015 USD ($)	Jul. 31, 2015 USD ($)
Debt Instrument [Line Items]
Repayments of debentures		$ 5,500,000	$ 1,000,000
Subordinated Debentures
Debt Instrument [Line Items]
Debenture term		30 years
Subordinated Debentures | Trust II Debentures
Debt Instrument [Line Items]
Debenture issued		$ 3,093,000
Subordinated Debentures | Trust II Debentures | Minimum
Debt Instrument [Line Items]
Notice period required for redemption of debentures		30 days
Subordinated Debentures | Trust II Debentures | Maximum
Debt Instrument [Line Items]
Notice period required for redemption of debentures		60 days
Redemption price of debentures as a percentage of principal		100.00%
Subordinated Debentures | Trust II Debentures | 3 Month LIBOR
Debt Instrument [Line Items]
Spread on variable rate		3.35%
Subordinated Debentures | Trust III Debentures
Debt Instrument [Line Items]
Debenture issued		$ 2,062,000
Subordinated Debentures | Trust III Debentures | Minimum
Debt Instrument [Line Items]
Notice period required for redemption of debentures		30 days
Subordinated Debentures | Trust III Debentures | Maximum
Debt Instrument [Line Items]
Notice period required for redemption of debentures		60 days
Redemption price of debentures as a percentage of principal		100.00%
Subordinated Debentures | Trust III Debentures | 3 Month LIBOR
Debt Instrument [Line Items]
Spread on variable rate		1.67%		1.67%
Subordinated Debentures | DCB Trust I Debentures
Debt Instrument [Line Items]
Debenture issued		$ 5,155,000
Subordinated Debentures | DCB Trust I Debentures | Minimum
Debt Instrument [Line Items]
Notice period required for redemption of debentures		30 days
Subordinated Debentures | DCB Trust I Debentures | Maximum
Debt Instrument [Line Items]
Notice period required for redemption of debentures		60 days
Redemption price of debentures as a percentage of principal		100.00%
Subordinated Debentures | DCB Trust I Debentures | 3 Month LIBOR
Debt Instrument [Line Items]
Spread on variable rate		1.80%
Subordinated Debentures | Other Debentures Issued in July 2015
Debt Instrument [Line Items]
Notice period required for redemption of debentures		30 days
Redemption price of debentures as a percentage of principal		100.00%
Debenture issued							$ 4,000,000
Subordinated Debentures | Other Debentures Issued in July 2015 | Directors and Related Parties
Debt Instrument [Line Items]
Debenture issued							$ 3,000,000
Repayments of debentures	$ 3,000,000
Subordinated Debentures | Other Subordinated Debentures, 2.50%
Debt Instrument [Line Items]
Debenture issued, par value per instrument issued					$ 500,000
Stated interest rate					2.50%
Subordinated Debentures | Other Subordinated Debentures, 4.00%
Debt Instrument [Line Items]
Debenture issued, par value per instrument issued		$ 500,000
Stated interest rate		4.00%
Subordinated Debentures | Other Debentures Issued in December 2015
Debt Instrument [Line Items]
Notice period required for redemption of debentures		30 days
Redemption price of debentures as a percentage of principal		100.00%
Debenture issued		$ 3,000,000				$ 5,000,000
Repayments of debentures	$ 2,000,000
Debenture issued, par value per instrument issued		$ 500,000
Subordinated Debentures | Other Debentures Issued in December 2015 | Directors and Related Parties
Debt Instrument [Line Items]
Debenture issued						$ 2,500,000
Subordinated Debentures | Other Debentures Issued in December 2015 | Minimum
Debt Instrument [Line Items]
Stated interest rate		3.00%
Subordinated Debentures | Other Debentures Issued in December 2015 | Maximum
Debt Instrument [Line Items]
Stated interest rate		5.00%
Capital trust pass-through securities
Debt Instrument [Line Items]
Number of trusts | trust		3
Liquidation value per share (in USD per share) | $ / shares		$ 1,000

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