FAIR VALUE MEASUREMENT (Narrative) (Details) - Fair Value, Inputs, Level 3 [Member] $ in Millions	Dec. 31, 2016 USD ($)
Four Point Five Percentage Convertible Notes [Member]
Convertible Debt, Fair Value Disclosures	$ 10.0
Four Point Five Percentage Convertible Notes [Member] | 2013 [Member]
Convertible Debt, Fair Value Disclosures	14.9
Four Point Five Percentage Convertible Notes [Member] | 2016 [Member]
Convertible Debt, Fair Value Disclosures	62.7
Seven Point Five Percentage Convertible Notes [Member]
Convertible Debt, Fair Value Disclosures	$ 64.0