FAIR VALUE - Fair Value of Assets and Liabilities Measured on a Nonrecurring Basis - (Details) - Non-recurring basis - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Assets:
Total impaired loans	$ 506		$ 1,140
Impaired servicing rights	474		531
Recorded investment of impaired loans	945		2,393
Valuation allowance of impaired loans	439		1,253
Provision expenses of impaired loans	125	$ 129
Gross outstanding balance of servicing rights	674		731
Valuation allowance of servicing rights	200		200
Commercial and industrial
Assets:
Total impaired loans	68		58
Other
Assets:
Total impaired loans	438		1,082
Recorded investment of impaired loans	795
Valuation allowance of impaired loans	357
Construction and development
Assets:
Total impaired loans	68
Recorded investment of impaired loans	150
Valuation allowance of impaired loans	82
Level 3
Assets:
Total impaired loans	506		1,140
Impaired servicing rights	474		531
Level 3 | Commercial and industrial
Assets:
Total impaired loans	68		58
Level 3 | Other
Assets:
Total impaired loans	$ 438		$ 1,082