FAIR VALUE MEASUREMENT (Narrative) (Details) $ in Millions	Jun. 30, 2017 USD ($)
Four Point Five Percentage Convertible Notes [Member]
Convertible Debt, Fair Value Disclosures	$ 14.9
Seven Point Five Percentage Convertible Notes [Member]
Convertible Debt, Fair Value Disclosures	51.9
Fair Value, Inputs, Level 3 [Member] | Four Point Five Percentage Convertible Notes [Member]
Convertible Debt, Fair Value Disclosures	11.5
Fair Value, Inputs, Level 3 [Member] | Seven Point Five Percentage Convertible Notes [Member]
Convertible Debt, Fair Value Disclosures	$ 75.1