RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS - Additional Information (Details) - 3.50% Convertible Senior Notes Due 2019	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Oct. 22, 2014
Debt Instrument [Line Items]
Interest rate	3.50%	3.50%
Convertible Debt
Debt Instrument [Line Items]
Interest rate	3.50%		3.50%	3.50%