FAIR VALUE MEASUREMENT (Narrative) (Details) $ in Millions	Sep. 30, 2017 USD ($)
Four Point Five Percentage Convertible Notes [Member]
Convertible Debt, Fair Value Disclosures	$ 5.9
Seven Point Five Percentage Convertible Notes [Member]
Convertible Debt, Fair Value Disclosures	61.9
Fair Value, Inputs, Level 3 [Member] | Four Point Five Percentage Convertible Notes [Member]
Convertible Debt, Fair Value Disclosures	5.0
Fair Value, Inputs, Level 3 [Member] | Four Point Five Percentage Convertible Notes One [Member]
Convertible Debt, Fair Value Disclosures	5.6
Fair Value, Inputs, Level 3 [Member] | Four Point Five Percentage Convertible Notes Two [Member]
Convertible Debt, Fair Value Disclosures	76.9
Fair Value, Inputs, Level 3 [Member] | Four Point Five Percentage Convertible Notes Three [Member]
Convertible Debt, Fair Value Disclosures	$ 5.3