MERGERS AND ACQUISITIONS - Acquisition Related Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Acquisition related costs	$ 0	$ 722	$ 310
Professional fees
Business Acquisition [Line Items]
Acquisition related costs	0	471	183
Marketing
Business Acquisition [Line Items]
Acquisition related costs	0	29	4
Printing, postage and supplies
Business Acquisition [Line Items]
Acquisition related costs	0	71	9
Equipment depreciation and maintenance
Business Acquisition [Line Items]
Acquisition related costs	0	0	26
Travel and entertainment
Business Acquisition [Line Items]
Acquisition related costs	0	50	88
Data processing and communications
Business Acquisition [Line Items]
Acquisition related costs	0	76	0
Other operating expense
Business Acquisition [Line Items]
Acquisition related costs	$ 0	$ 25	$ 0