EARNINGS PER COMMON SHARE - Anti-dilutive Securities (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
EARNINGS PER COMMON SHARE
Total potentially dilutive securities	649,672	806,309	608,731	762,982
Stock options
EARNINGS PER COMMON SHARE
Total potentially dilutive securities	419,197	442,097	419,197	445,947
Time Vesting Units
EARNINGS PER COMMON SHARE
Total potentially dilutive securities	92,388	198,611	89,656	179,301
Financial Performance Units
EARNINGS PER COMMON SHARE
Total potentially dilutive securities	96,257	70,865	48,129	42,998
Restricted Stock Awards
EARNINGS PER COMMON SHARE
Total potentially dilutive securities	41,830	94,736	51,749	94,736