Collaboration Agreements (Tables)

12 Months Ended

Dec. 31, 2017

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Schedule of Revenues from Collaborations

The following table is a summary of the revenue recognized from the Company’s collaborations for each of the years ended December 31, 2017, 2016 and 2015.

	Year Ended December 31,
	2017		2016		2015
Teva:
Recognition of upfront payment	$	—	$	—	$	10,897
Research funding		59		116		112
Genentech:
Recognition of upfront payment		—		157		725
Research funding		—		1,494		3,589
Milestone payments		250		—		250
Total collaboration revenue	$	309	$	1,767	$	15,573