Annual report pursuant to Section 13 and 15(d)

SEGMENT REPORTING (Narrative) (Details)

v3.8.0.1
SEGMENT REPORTING (Narrative) (Details)
$ in Millions
3 Months Ended 12 Months Ended
Dec. 31, 2017
USD ($)
Sep. 30, 2017
USD ($)
Jun. 30, 2017
USD ($)
Mar. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Sep. 30, 2016
USD ($)
Jun. 30, 2016
USD ($)
Mar. 31, 2016
USD ($)
Dec. 31, 2017
USD ($)
customer
Dec. 31, 2016
USD ($)
customer
Dec. 31, 2015
USD ($)
customer
Segment Reporting Information [Line Items]                      
Revenues $ 600.9 $ 698.4 $ 569.3 $ 461.6 $ 754.0 $ 553.3 $ 496.2 $ 305.5 $ 2,330.2 $ 2,109.0 $ 2,013.3
Sales Revenue, Net [Member] | Customer Concentration Risk [Member]                      
Segment Reporting Information [Line Items]                      
Number of Customers | customer                 2 2 3
Concentration Risk, Percentage                 10.00% 10.00% 10.00%
Revenues                 $ 1,300.0 $ 1,100.0 $ 1,300.0