INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Apr. 02, 2015	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Intangible assets
Gross Carrying Amount		$ 1,098,588		$ 1,098,588		$ 1,098,588
Accumulated amortization		(355,603)		(355,603)		(304,715)
Total		742,985		742,985		793,873
Amortization of intangible assets		25,444	$ 25,735	50,888	$ 51,470
Future amortization expenses of intangible assets
2018 (remainder)		50,886		50,886
2019		101,774		101,774
2020		101,774		101,774
2021		101,774		101,774
2022		99,969		99,969
Thereafter		286,808		$ 286,808
NUCYNTA
Intangible assets
Remaining Useful Life (In years)	10 years
Product rights | NUCYNTA
Intangible assets
Remaining Useful Life (In years)				7 years 6 months
Gross Carrying Amount		1,019,978		$ 1,019,978		1,019,978
Accumulated amortization		(313,740)		(313,740)		(266,590)
Total		706,238		$ 706,238		753,388
Product rights | CAMBIA
Intangible assets
Remaining Useful Life (In years)				5 years 6 months
Gross Carrying Amount		51,360		$ 51,360		51,360
Accumulated amortization		(23,323)		(23,323)		(20,755)
Total		28,037		$ 28,037		30,605
Product rights | Zipsor
Intangible assets
Remaining Useful Life (In years)				3 years 9 months 18 days
Gross Carrying Amount		27,250		$ 27,250		27,250
Accumulated amortization		(18,540)		(18,540)		(17,370)
Total		$ 8,710		$ 8,710		$ 9,880