CASH, CASH EQUIVALENTS, SHORT-TERM INVESTMENTS AND MARKETABLE SECURITIES, LONG-TERM - LEVEL 3 (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015	Sep. 09, 2014
Convertible Notes
Estimated fair value of debt instruments
Interest rate (as a percent)	2.50%		2.50%
Par value of debt	$ 345,000	$ 345,000	$ 345,000
Level 2 | Convertible Notes | Fair Value
Estimated fair value of debt instruments
Estimated fair value of debt	379,500	$ 395,000
Contingent consideration | Level 3
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Balance at the beginning of the period	14,971
Balance at the end of the period	14,898
Contingent consideration | Level 3 | Interest Expense.
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Net accretion value adjustments	1,194
Contingent consideration | Level 3 | Selling general and administrative expense
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Net accretion value adjustments	(287)
Contingent consideration | Level 3 | Royalties Paid
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Net accretion value adjustments	(980)
Contingent consideration | Level 3 | Zipsor
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Balance at the beginning of the period	1,504
Balance at the end of the period	1,241
Contingent consideration | Level 3 | Zipsor | Interest Expense.
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Net accretion value adjustments	69
Contingent consideration | Level 3 | Zipsor | Selling general and administrative expense
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Net accretion value adjustments	(332)
Contingent consideration | Level 3 | Lazanda
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Balance at the beginning of the period	12,002
Balance at the end of the period	12,156
Contingent consideration | Level 3 | Lazanda | Interest Expense.
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Net accretion value adjustments	1,009
Contingent consideration | Level 3 | Lazanda | Selling general and administrative expense
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Net accretion value adjustments	125
Contingent consideration | Level 3 | Lazanda | Royalties Paid
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Net accretion value adjustments	(980)
Contingent consideration | Level 3 | CAMBIA
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Balance at the beginning of the period	1,465
Balance at the end of the period	1,501
Contingent consideration | Level 3 | CAMBIA | Interest Expense.
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Net accretion value adjustments	116
Contingent consideration | Level 3 | CAMBIA | Selling general and administrative expense
Changes in fair value of all financial liabilities measured at fair value on a recurring basis
Net accretion value adjustments	$ (80)