Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2013

Fair Value Disclosures [Abstract]

Fair Value, Measurement Inputs

The Company's assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability:

	As of June 30, 2013								As of December 31, 2012
Assets and Liabilities	Quoted Prices In Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs  (Level 2)		Significant Unobservable Inputs  (Level 3)		Balance as of June 30, 2013		Quoted Prices In Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs  (Level 2)		Significant Unobservable Inputs  (Level 3)		Balance as of December 31, 2012
	(in thousands)
Assets:
Money market	$	37,831	$	—	$	—	$	37,831	$	14,751	$	—	$	—	$	14,751
U.S. government agency notes	—		—		—		—		—		7,097		—		7,097
Corporate debt securities	—		8,112		—		8,112		—		43,778		—		43,778
Total assets at fair value	$	37,831	$	8,112	$	—	$	45,943	$	14,751	$	50,875	$	—	$	65,626
Liabilities:
Contingent purchase price	$	—	$	—	$	100,524	$	100,524	$	—	$	—	$	18,971	$	18,971
Total liabilities at fair value	$	—	$	—	$	100,524	$	100,524	$	—	$	—	$	18,971	$	18,971

Fair Value Inputs, Quantitative Information

The following table provides quantitative information associated with the fair value measurement of the Company’s Level 3 inputs:

	Fair Value as of
	June 30, 2013		Valuation Technique	Unobservable Input	Range (Weighted Average)
	(in thousands)
Targanta:
Contingent purchase price	$	5,424	Probability-adjusted discounted cash flow	Probability of success	20%
				Period in which milestone is expected to be achieved	2019
				Discount rate	11%
Incline:
Contingent purchase price	$	95,100	Probability-adjusted discounted cash flow	Probabilities of success	60% - 80% (75%)
				Periods in which milestones are expected to be achieved	2013-2017
				Discount Rate	22%

	Fair Value as of
	December 31, 2012		Valuation Technique	Unobservable Input	Range (Weighted Average)
	(in thousands)
Targanta:
Contingent purchase price	$	18,971	Probability-adjusted discounted cash flow	Probabilities of success	20% - 60% (49%)
				Periods in which milestones are expected to be achieved	2013 - 2019
				Discount rate	11%

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation

The changes in fair value of the Company's Level 3 contingent purchase price during the three and six months ended June 30, 2013 and 2012 were as follows:

	Three Months Ended June 30,					Six Months Ended June 30,
	2013			2012		2013			2012
	(in thousands)
Balance at beginning of period	$	105,807		$	20,995	$	18,971		$	20,431
Fair value of contingent purchase price with respect to Incline as of January 4, 2013	—			—		87,200			—
Fair value adjustment to contingent purchase prices included in net income	(5,283		)	573		(5,647		)	1,137
Balance at end of period	$	100,524		$	21,568	$	100,524		$	21,568