LONG-TERM DEBT - Schedule of Long-term Debt, Net of Discounts (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Oct. 22, 2014
Debt Instrument [Line Items]
Term loan facility	$ 74,000	$ 87,750
Unamortized discount on convertible senior notes	(16,978)	(20,116)
Long-term debt	200,772	211,384
Less: current portion of long-term debt	10,278	9,563
Long-term debt, net, less current portion	$ 190,494	$ 201,821
3.50% Convertible Senior Notes Due 2019
Debt Instrument [Line Items]
Interest rate	3.50%	3.50%	3.50%
3.50% convertible senior notes due 2019	$ 143,750	$ 143,750