Annual report pursuant to Section 13 and 15(d)

EMPLOYEE BENEFITS (Details)

v3.6.0.2
EMPLOYEE BENEFITS (Details) - USD ($)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
EMPLOYEE BENEFITS [Abstract]      
Employer matching contribution, first 100.00%    
Employee contribution, first 3.00%    
Employer matching contribution, second 50.00%    
Employee contribution, second 3.00%    
Maximum employer matching contribution 5.00%    
Employer contributions $ 673,000 $ 665,000 $ 630,000
Number of shares of common stock reserved to be issued under Employee Stock Purchase Plan (in shares) 210,000