INVESTMENTS (Details 2) (USD $)	9 Months Ended				1 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Optimer Pharmaceuticals, Inc.	Sep. 16, 2013 Option agreement Non-voting senior preferred stock	Feb. 28, 2013 Option agreement Adynxx	Sep. 30, 2013 Option agreement Adynxx	Sep. 30, 2013 Excluded portion	Dec. 31, 2012 Excluded portion
Amortized Cost
Within 1 year, Amortized Cost	$ 370,450,000	$ 812,104,000
1-2 years, Amortized Cost	76,670,000	3,171,000
Amortized Cost	447,120,000	815,275,000
Fair Value
Within 1 year, Fair Value	370,530,000	812,052,000
1-2 years, Fair Value	76,639,000	3,167,000
Fair Value	447,169,000	815,219,000
Certificates of deposit							12,200,000	60,100,000
Payment for purchase option, non-refundable except in limited circumstances	20,000,000				20,000,000
Percentage of outstanding shares to be acquired under option in exchange for $20.0 million non-refundable payment					100.00%
Maximum number of days purchase option is exercisable					60 days
Additional payment to be made on exercise of option					40,000,000
Amount of payment which represents the maximum exposure to any potential losses associated with this VIE, at cost, subject to impairment testing						20,000,000
Carrying value of the investments included in prepaid expenses and other current assets				25,000,000		20,000,000
Amount agreed to be provided to acquiree per quarter to fund their operations in exchange for non-voting senior preferred stock			25,000,000
Maximum amount agreed to be provided to acquiree to fund their operations in exchange for non-voting senior preferred stock			$ 75,000,000