PENSION PLAN - Plan Assets at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Plan's assets at fair value by level, within the fair value hierarchy
Total assets at fair value	$ 4,573	$ 4,486	$ 4,471
Level I
Plan's assets at fair value by level, within the fair value hierarchy
Total assets at fair value	4,161	3,634
Level III
Plan's assets at fair value by level, within the fair value hierarchy
Total assets at fair value	412	852
Cash
Plan's assets at fair value by level, within the fair value hierarchy
Total assets at fair value	732	449
Cash | Level I
Plan's assets at fair value by level, within the fair value hierarchy
Total assets at fair value	732	449
Fixed income
Plan's assets at fair value by level, within the fair value hierarchy
Total assets at fair value	1,280	897
Fixed income | Level I
Plan's assets at fair value by level, within the fair value hierarchy
Total assets at fair value	1,280	897
Alternative investments
Plan's assets at fair value by level, within the fair value hierarchy
Total assets at fair value	412	852
Alternative investments | Level III
Plan's assets at fair value by level, within the fair value hierarchy
Total assets at fair value	412	852
Domestic equities
Plan's assets at fair value by level, within the fair value hierarchy
Total assets at fair value	1,280	1,436
Domestic equities | Level I
Plan's assets at fair value by level, within the fair value hierarchy
Total assets at fair value	1,280	1,436
Foreign equities
Plan's assets at fair value by level, within the fair value hierarchy
Total assets at fair value	869	852
Foreign equities | Level I
Plan's assets at fair value by level, within the fair value hierarchy
Total assets at fair value	$ 869	$ 852