MARKETABLE SECURITIES (Details 3) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair value hierarchy for financial assets and liabilities
Liabilities, contingent consideration	$ 14,252	$ 11,264
Recurring | Level 1
Fair value hierarchy for financial assets and liabilities
Assets	290,113	217,946
Recurring | Level 1 | Corporate debt securities
Fair value hierarchy for financial assets and liabilities
Assets	110,190
Recurring | Level 1 | Money market funds
Fair value hierarchy for financial assets and liabilities
Assets	179,923	217,946
Recurring | Level 2
Fair value hierarchy for financial assets and liabilities
Assets	253,837	31,343
Recurring | Level 2 | Corporate debt securities
Fair value hierarchy for financial assets and liabilities
Assets		16,526
Recurring | Level 2 | U.S. government agency debt securities
Fair value hierarchy for financial assets and liabilities
Assets		14,817
Recurring | Level 2 | Commercial Paper
Fair value hierarchy for financial assets and liabilities
Assets	253,837
Recurring | Level 3
Fair value hierarchy for financial assets and liabilities
Unfavorable contract assumed	3,343	3,540
Liabilities	17,595	14,804
Recurring | Level 3 | Zipsor
Fair value hierarchy for financial assets and liabilities
Liabilities, contingent consideration	1,800	1,638
Recurring | Level 3 | Lazanda
Fair value hierarchy for financial assets and liabilities
Liabilities, contingent consideration	11,209	8,616
Recurring | Level 3 | CAMBIA
Fair value hierarchy for financial assets and liabilities
Liabilities, contingent consideration	1,243	1,010
Recurring | Fair Value
Fair value hierarchy for financial assets and liabilities
Assets	543,950	249,289
Unfavorable contract assumed	3,343	3,540
Liabilities	17,595	14,804
Recurring | Fair Value | Zipsor
Fair value hierarchy for financial assets and liabilities
Liabilities, contingent consideration	1,800	1,638
Recurring | Fair Value | Lazanda
Fair value hierarchy for financial assets and liabilities
Liabilities, contingent consideration	11,209	8,616
Recurring | Fair Value | CAMBIA
Fair value hierarchy for financial assets and liabilities
Liabilities, contingent consideration	1,243	1,010
Recurring | Fair Value | Corporate debt securities
Fair value hierarchy for financial assets and liabilities
Assets	110,190	16,526
Recurring | Fair Value | U.S. government agency debt securities
Fair value hierarchy for financial assets and liabilities
Assets		14,817
Recurring | Fair Value | Money market funds
Fair value hierarchy for financial assets and liabilities
Assets	179,923	217,946
Recurring | Fair Value | Commercial Paper
Fair value hierarchy for financial assets and liabilities
Assets	$ 253,837