FAIR VALUE MEASUREMENTS - Assets and Liabilities Measured at Fair Value on a Non-recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Capitalized mortgage servicing rights
Moving average term of U.S. Treasury rate used to estimate the discount rate in order to determine the fair value of servicing rights (in years)	10 years	10 years
Servicing Assets at Fair Value Assumptions Used to Estimate Fair Value Discount Rate Basis Spread on Variable Rate	5.00%	5.00%
Short-term FHLB advances
Maturity period of short-term FHLB advances	90 days
Securities available for sale	$ 18,847	$ 19,772
Residential mortgage-backed securities
Short-term FHLB advances
Securities available for sale	16,452	17,387
State and municipal
Short-term FHLB advances
Securities available for sale	2,395	2,385
Level 2
Short-term FHLB advances
Securities available for sale	18,847	19,772
Recurring basis | Total Assets at Fair Value
Short-term FHLB advances
Securities available for sale	18,847	19,772
Recurring basis | Total Assets at Fair Value | Residential mortgage-backed securities
Short-term FHLB advances
Securities available for sale	16,452	17,387
Recurring basis | Total Assets at Fair Value | State and municipal
Short-term FHLB advances
Securities available for sale	2,395	2,385
Recurring basis | Level 2
Short-term FHLB advances
Securities available for sale	18,847	19,772
Recurring basis | Level 2 | Residential mortgage-backed securities
Short-term FHLB advances
Securities available for sale	16,452	17,387
Recurring basis | Level 2 | State and municipal
Short-term FHLB advances
Securities available for sale	$ 2,395	$ 2,385