Annual report pursuant to Section 13 and 15(d)

STOCK-BASED COMPENSATION (Restricted Stock Narrative) (Details)

v3.8.0.1
STOCK-BASED COMPENSATION (Restricted Stock Narrative) (Details) - USD ($)
shares in Thousands, $ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total fair market value of the shares issued upon vesting $ 11.5 $ 10.5 $ 11.2  
Restricted Stock [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Restricted shares granted 1,132 751 456  
Shares that will begin to vest on achieving minimum performance targets (in shares) 1,607 1,080 861 1,171
Restricted Stock [Member] | Minimum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period 1 year      
Restricted Stock [Member] | Maximum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period 5 years      
Non-Market Based or Performance Based Restricted Stock Awards [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Restricted shares granted 900 400 300  
Non-Market Based or Performance Based Restricted Stock Awards [Member] | Minimum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period 1 year 1 year 1 year  
Non-Market Based or Performance Based Restricted Stock Awards [Member] | Maximum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period 4 years 4 years 4 years  
Restricted Stock Performance Based Awards [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period   2 years 2 years  
Restricted shares granted 200 400 200  
Shares that will begin to vest on achieving minimum performance targets (in shares) 200      
Restricted Stock Performance Based Awards [Member] | Minimum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period 1 year      
Restricted Stock Performance Based Awards [Member] | Maximum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period 2 years