EARNINGS PER COMMON SHARE - Anti-dilutive Securities (Details) - shares	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
EARNINGS PER COMMON SHARE
Total potentially dilutive securities	567,788	719,654
Stock options
EARNINGS PER COMMON SHARE
Total potentially dilutive securities	419,197	449,797
Time Vesting Units
EARNINGS PER COMMON SHARE
Total potentially dilutive securities	86,923	159,991
Financial Performance Units
EARNINGS PER COMMON SHARE
Total potentially dilutive securities		15,130
Restricted Stock Awards
EARNINGS PER COMMON SHARE
Total potentially dilutive securities	61,668	94,736

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration