Note 4 - Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2017

Notes Tables

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

			Fair Value Measurements at March 31, 2017
			Quoted Prices in		Significant Other		Significant
			Active Markets for		Observable		Unobservable
	Balance at		Identical Assets		Inputs		Inputs
	March 31, 2017		(Level 1)		(Level 2)		(Level 3)
Assets:
Money market funds	$	122,351	$	122,351	$	-	$	-
Total assets	$	122,351	$	122,351	$	-	$	-
Liabilities:
Contingent consideration liability	$	16,100	$	-	$	-	$	16,100
Total liabilities	$	16,100	$	-	$	-	$	16,100

			Fair Value Measurements at December 31, 2016
			Quoted Prices in		Significant Other		Significant
			Active Markets for		Observable		Unobservable
	Balance at		Identical Assets		Inputs		Inputs
	December 31, 2016		(Level 1)		(Level 2)		(Level 3)
Assets:
Money market funds	$	137,340	$	137,340	$	-	$	-
Total assets	$	137,340	$	137,340	$	-	$	-
Liabilities:
Contingent consideration liability	$	14,200	$	-	$	-	$	14,200
Total liabilities	$	14,200	$	-	$	-	$	14,200

Fair Value Inputs, Assets and Liabilities, Quantitative Information [Table Text Block]

	Fair Value at
	March 31,				Range
	2017		Valuation Technique	Unobservable Input	(Weighted-Average)
Contingent Consideration Liability:
AZEDRA commercialization	$	5,100	Probability adjusted discounted	Probability of success			72%
			cash flow model	Period of expected milestone achievement			2018
				Discount rate			10%
1404 commercialization		4,800	Probability adjusted discounted	Probability of success			59%
			cash flow model	Period of expected milestone achievement			2019
				Discount rate			10%
1095 commercialization		400	Probability adjusted discounted	Probability of success			16%
			cash flow model	Period of expected milestone achievement			2024
				Discount rate			10%
Net sales targets		5,800	Monte-Carlo simulation	Probability of success		16%	-	72%
				Discount rate			10%
Total	$	16,100

	Fair Value at
	December 31,				Range
	2016		Valuation Technique	Unobservable Input	(Weighted-Average)
Contingent Consideration Liability:
AZEDRA commercialization	$	3,800	Probability adjusted discounted	Probability of success		54%
			cash flow model	Period of expected milestone achievement		2018
				Discount rate		10%
1404 commercialization		4,700	Probability adjusted discounted	Probability of success		59%
			cash flow model	Period of expected milestone achievement		2019
				Discount rate		10%
1095 commercialization		400	Probability adjusted discounted	Probability of success		16%
			cash flow model	Period of expected milestone achievement		2024
				Discount rate		10%
Net sales targets		5,300	Monte-Carlo simulation	Probability of success	16%	-	59%
				Discount rate		10%
Total	$	14,200

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

	Liability - Contingent Consideration
	Fair Value Measurements Using
	Significant Unobservable Inputs
	(Level 3)
	For the Three Months Ended March 31,
	2017		2016
Balance at beginning of period	$	14,200	$	18,800
Fair value change included in net loss		1,900		200
Balance at end of period	$	16,100	$	19,000
Changes in unrealized gains or losses for the period
included in earnings (or changes in net assets) for
liabilities held at the end of the reporting period	$	1,900	$	200