FAIR VALUE MEASUREMENTS (Details 2) (USD $)					9 Months Ended			9 Months Ended					9 Months Ended					9 Months Ended			1 Months Ended										9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014 Optimer Pharmaceuticals, Inc. right	Dec. 31, 2013 Optimer Pharmaceuticals, Inc.	Oct. 24, 2013 Optimer Pharmaceuticals, Inc. right	Sep. 30, 2014 Trius Therapeutics, Inc.	Dec. 31, 2013 Trius Therapeutics, Inc.	Sep. 11, 2013 Trius Therapeutics, Inc. right	Sep. 30, 2014 Trius Therapeutics, Inc. Minimum	Sep. 30, 2014 Trius Therapeutics, Inc. Maximum	Sep. 30, 2014 Trius Therapeutics, Inc. Weighted Average	Sep. 30, 2014 Adolor Corporation	Dec. 31, 2013 Adolor Corporation	Sep. 30, 2014 Adolor Corporation Minimum	Sep. 30, 2014 Adolor Corporation Maximum	Sep. 30, 2014 Adolor Corporation Weighted Average	Sep. 30, 2014 Calixa Therapeutics Inc.	Dec. 31, 2013 Calixa Therapeutics Inc.	Sep. 30, 2014 Calixa Therapeutics Inc. Minimum	Sep. 30, 2014 Calixa Therapeutics Inc. Maximum	Sep. 30, 2014 Calixa Therapeutics Inc. Weighted Average	Dec. 31, 2011 Glaxo Group Limited [Member] AnnualPayment	Sep. 30, 2014 Glaxo Group Limited [Member]	Sep. 30, 2014 Level 2	Dec. 31, 2013 Level 2	Sep. 30, 2014 Level 2 2020 Convertible Senior Notes	Dec. 31, 2013 Level 2 2020 Convertible Senior Notes	Sep. 30, 2014 Level 2 2018 Convertible Senior Notes	Dec. 31, 2013 Level 2 2018 Convertible Senior Notes	Sep. 30, 2014 Level 2 2017 Convertible Senior Notes	Dec. 31, 2013 Level 2 2017 Convertible Senior Notes	Sep. 30, 2014 Level 3 Contingent Consideration	Sep. 30, 2014 Recurring Basis Level 1 Optimer Pharmaceuticals, Inc.	Sep. 30, 2014 Recurring Basis Level 2 Optimer Pharmaceuticals, Inc.	Sep. 30, 2014 Recurring Basis Level 3 Optimer Pharmaceuticals, Inc.
Contingent Consideration
Number of transferable CVRs received by stockholders of acquiree		1		1			1
Undiscounted contingent consideration, low range		$ 0			$ 0						$ 0					$ 0
Undiscounted contingent consideration, high range		253,900,000		253,900,000	108,400,000		108,400,000				233,800,000					180,000,000
Level 3 Disclosures
Contingent consideration	161,360,000		68,600,000		5,310,000	5,000,000					46,128,000	44,200,000				109,922,000	105,600,000															6,094,000	0	0
Probability of success (as a percent)								4.00%	6.50%	5.80%			25.00%	30.00%	27.00%			40.00%	86.00%	65.00%
Discount rate (as a percent)					8.00%								5.30%	13.00%		5.30%
Reconciliation of fair value using Level 3 inputs, liabilities
Balance at the beginning of the period																															154,761,000
Contingent consideration expense																															6,599,000
Balance at the end of the period																															161,360,000
Other Fair Value Measurements
Total estimated fair value of Convertible Senior Notes																							1,404,520,000	1,470,633,000	499,235,000	516,843,000	378,452,000	403,473,000	526,833,000	550,317,000
Number of annual payments under termination agreement																					6
Aggregate payments assumed																					22,500,000
Net carrying amount of the total payable to Glaxo outstanding at the end of the period																						$ 11,300,000