Fair Value (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value Measurements Disclosure [Line Items]

Summary of Assets Measured at Fair Value on Recurring Basis

The following are the major categories of assets measured at fair value on a recurring basis as of December 31, 2018 and 2017, using quoted prices in active markets for identical assets (Level 1); significant other observable inputs (Level 2); and significant unobservable inputs (Level 3):

	December 31, 2018
	(In thousands)
	(unaudited)
Description	QuotedPrices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets measured at fair value
Cash and cash equivalents	$	21,061	$	—	$	—	$	21,061
Restricted cash		590		—		—		590
Total Assets measured at fair value	$	21,651	$	—	$	—	$	21,651
Liabilities measured at fair value
Contingent consideration	$	—	$	—	$	10,637	$	10,637
Warrant liabilities		—		—	$	4,636	$	4,636
Total liabilities measured at fair value	$	—	$	—	$	15,273	$	15,273

	December 31, 2017
	(In thousands)
Description	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets measured at fair value
Cash and cash equivalents	$	91,217	$	—	$	—	$	91,217
Restricted cash		6,389		—		—		6,389
Total Assets measured at fair value	$	97,606	$	—	$	—	$	97,606
Liabilities measured at fair value
Contingent consideration	$	—	$	—	$	12,418	$	12,418
Warrant liabilities		—		—		14,090		14,090
Total liabilities measured at fair value	$	—	$	—	$	26,508	$	26,508

Change in Fair Value for All Assets and Liabilities Using Unobservable Level 3 Inputs As Determined By Level 3 Inputs

The following table summarizes the change in fair value, as determined by Level 3 inputs, for all assets and liabilities using unobservable Level 3 inputs for the years ended December 31, 2018, 2017 and 2016:

	Fair Value Measurementat Reporting Date (Level 3)
	(In thousands)
	Common stock			Contingent
	warrants			consideration
Balance at December 31, 2015		—			23,500
Payment for contingent consideration		—			(1,182	)
Change in fair value		—			482
Balance at December 31, 2016		—			22,800
Issuance of common stock in exchange for contingent    consideration		—			(5,227	)
Issuance of warrants		8,715			—
Payment for contingent consideration		—			(7,181	)
Exercise of warrants		(78,359	)		—
Change in fair value		83,734			2,026
Balance at December 31, 2017		14,090			12,418
Payment for contingent consideration		—			(770	)
Exercise of warrants		(23,774	)		—
Change in fair value		14,320			(1,011	)
Balance at December 31, 2018		4,636		$	10,637
Current portion		—			72
Long-term portion		4,636			10,565
Balance at December 31, 2018	$	4,636		$	10,637

Level 3 [Member]

Fair Value Measurements Disclosure [Line Items]

Quantitative Information about Inputs and Valuation Methodologies Used for Fair Value Measurements Classification

The following table presents quantitative information about the inputs and valuation methodologies used for the Company’s fair value measurements classified in Level 3 with the exception of the warrant liability, which is explained above as of December 31, 2018 and 2017:

	Valuation Methodology	Significant Unobservable Input	WeightedAverage (range, if applicable)
Contingent  consideration	Probabilityweighted income approach	Milestone dates	2019 to2022
		Discount rate	11.5% to 12%

Series B Warrant [Member]

Fair Value Measurements Disclosure [Line Items]

Quantitative Information about Inputs and Valuation Methodologies Used for Fair Value Measurements Classification

The following table presents the inputs and valuation methodologies used for the Company’s fair value of the Series B warrants

					April 28, 2017
Series B	December 31, 2018		December 31, 2017		(date of issuance)
Fair value	$4.6 million		$14.1 million		$6.2 million
Valuation methodology	Monte Carlo		Monte Carlo		Black-Scholes Merton
Term	3.32 years		4.33 years		5 years
Risk free rate	2.47%		2.13%		1.81%
Dividends		—		—		—
Volatility	87.60%		80.60%		73.14%
Share price	$	2.26	$	1.93	$	0.65
Probability of additional financing	100% in 2019		25% in 2018 and 75% in 2019		Not Applicable