Collaboration Agreements (Tables)

12 Months Ended

Dec. 31, 2018

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Summary of Contract Liabilities Related to Company's Collaboration Agreements

Contract liabilities related to the Company’s collaboration agreements consisted of the following (in thousands):

	December 31, 2018		December 31, 2017
Current portion of deferred revenue	$	1,752	$	8,757
Deferred revenue, net of current portion		1,067		4,497
Total contract liabilities	$	2,819	$	13,254
Revenue recognized in the period from:
Amounts included in contract liability at the beginning of    the period	$	10,434	$	21