EMPLOYEE BENEFIT PLANS (Details 2)	Dec. 31, 2018
S&P Index
Employee benefit plans
Performance benchmark of special index (as a percent)	35.00%
Russell 2000 Index
Employee benefit plans
Performance benchmark of special index (as a percent)	15.00%
MSCI EAFE Index
Employee benefit plans
Performance benchmark of special index (as a percent)	10.00%
Lehman Aggregate Bond Index
Employee benefit plans
Performance benchmark of special index (as a percent)	40.00%