Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2019

Fair Value Disclosures [Abstract]

Summary of the Company's Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table presents information about the Company’s assets and liabilities that are measured at fair value on a recurring basis and indicates the fair value hierarchy of the valuation techniques the Company utilized to determine such fair value:

	March 31,
(In thousands)	2019		Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	62,556	$	62,556	$	—	$	—
U.S. government and agency debt securities		119,296		68,704		50,592		—
Corporate debt securities		185,073		—		185,073		—
International government agency debt securities		91,941		—		91,941		—
Contingent consideration		37,600		—		—		37,600
Common stock warrants		772		—		—		772
Total	$	497,238	$	131,260	$	327,606	$	38,372

	December 31,
	2018		Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	54,590	$	54,590	$	—	$	—
U.S. government and agency debt securities		98,513		60,107		38,406		—
Corporate debt securities		173,637		—		173,145		492
International government agency debt securities		77,504		—		77,504		—
Contingent consideration		65,200		—		—		65,200
Common stock warrants		1,205		—		—		1,205
Total	$	470,649	$	114,697	$	289,055	$	66,897

Rollforward of the Fair Value of the Assets Determined using Level 3 Inputs

The following table is a rollforward of the fair value of the Company’s assets whose fair values were determined using Level 3 inputs at March 31, 2019:

(In thousands)	Fair Value
Balance, January 1, 2019	$	66,897
Change in the fair value of contingent consideration		(22,600	)
Payment received for contingent consideration		(5,000	)
Impairment of corporate debt security		(492	)
Decrease in the fair value of warrants		(433	)
Balance, March 31, 2019	$	38,372