EMPLOYEE STOCK PLANS - Unvested Options (Details) - Stock options	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Number of Options
Unvested options outstanding, beginning of year (in shares) | shares	20,256
Vested (in shares) | shares	(5,255)
Forfeited (in shares) | shares	(15,001)
Unvested options outstanding, end of year (in shares) | shares	0
Weighted Average Grant Date Fair Value
Unvested options outstanding, beginning of year (in dollars per share) | $ / shares	$ 4.97
Vested (in dollars per share) | $ / shares	5.59
Forfeited (in dollars per share) | $ / shares	4.76
Unvested options outstanding, end of year (in dollars per share) | $ / shares	$ 0.00