PLEDGED ASSETS - Assets Pledged By Counterparties (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Pledged Assets [Line Items]
Securities Pledged By Counterparties	$ 9,940,000	$ 3,631,000
Residential Mortgage Backed Securities [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	548,000	0
Residential Mortgage Backed Securities [Member] | Pass Through Certificate [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	548,000	0
USTreasurySecuritiesMember
Pledged Assets [Line Items]
Securities Pledged By Counterparties	1,077,000	0
Cash
Pledged Assets [Line Items]
Securities Pledged By Counterparties	8,315,000	3,631,000
Repurchase Agreement [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	2,771,000	67,000
Repurchase Agreement [Member] | Residential Mortgage Backed Securities [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	548,000	0
Repurchase Agreement [Member] | Residential Mortgage Backed Securities [Member] | Pass Through Certificate [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	548,000	0
Repurchase Agreement [Member] | USTreasurySecuritiesMember
Pledged Assets [Line Items]
Securities Pledged By Counterparties	1,077,000	0
Repurchase Agreement [Member] | Cash
Pledged Assets [Line Items]
Securities Pledged By Counterparties	1,146,000	67,000
Derivative [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	7,169,000	3,564,000
Derivative [Member] | Residential Mortgage Backed Securities [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	0	0
Derivative [Member] | Residential Mortgage Backed Securities [Member] | Pass Through Certificate [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	0	0
Derivative [Member] | USTreasurySecuritiesMember
Pledged Assets [Line Items]
Securities Pledged By Counterparties	0	0
Derivative [Member] | Cash
Pledged Assets [Line Items]
Securities Pledged By Counterparties	$ 7,169,000	$ 3,564,000