Annual report pursuant to Section 13 and 15(d)

EMPLOYEE BENEFIT PLANS (Details)

v3.6.0.2
EMPLOYEE BENEFIT PLANS (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
401(k) plans      
Employer's matching contribution (as a percent) 70.00%    
Maximum contribution by employer as a percentage of employee's compensation 5.00%    
Employer's matching contribution before change (as a percent) 60.00%    
Vesting period of employer's contributions 3 years    
Contributions by employer $ 1.1 $ 0.9 $ 0.8
Nonqualified deferred compensation plan      
Maximum percentage of annual salary and bonus that may be deferred 100.00%    
Period for payment of obligation upon separation, one 3 years    
Period for payment of obligation upon separation, two 5 years    
Deferred compensation plan assets $ 1.4 $ 1.0