Annual report pursuant to Section 13 and 15(d)

SUBSEQUENT EVENTS (Details)

v3.8.0.1
SUBSEQUENT EVENTS (Details) - USD ($)
Feb. 12, 2018
Jan. 25, 2018
Dec. 31, 2017
Subsequent event [Member] | Positive outcome of litigation [Member]      
Subsequent Event [Line Items]      
Litigation settlement received $ 4,800,000    
Revolving credit facility [Member] | Line of credit [Member]      
Subsequent Event [Line Items]      
Current borrowing capacity     $ 625,000,000
Revolving credit facility [Member] | Line of credit [Member] | Revolving credit facility due July 2021 [Member]      
Subsequent Event [Line Items]      
Current borrowing capacity     565,000,000
Revolving credit facility [Member] | Line of credit [Member] | Revolving credit facility due July 2021 [Member] | Subsequent event [Member]      
Subsequent Event [Line Items]      
Current borrowing capacity   $ 625,000,000  
Revolving credit facility [Member] | Line of credit [Member] | Revolving credit facility maturing July 2019 [Member]      
Subsequent Event [Line Items]      
Current borrowing capacity     $ 60,000,000.0