Collaboration Revenue (Tables) - ASU 2014-09 [Member]

9 Months Ended

Sep. 30, 2018

Adjustments to Accounts on Condensed Consolidated Balance Sheet

The cumulative effect of applying the new guidance to all contracts with customers that were not completed as of January 1, 2018, was recorded as an adjustment to accumulated deficit as of the adoption date. As a result of applying the modified retrospective method to adopt the new revenue guidance, the following adjustments were made to accounts on the condensed consolidated balance sheet as of January 1, 2018:

	As Reported at			Adjustments Due to			Balance at
	December 31, 2017			ASC 606			January 1, 2018
Deferred revenue - related party		12,079			5,339			17,418
Deferred revenue, net of current portion - related party		84,847			21,518			106,365
Accumulated deficit		(263,571	)		(26,857	)		(290,428	)

Comparison of Reported Condensed Consolidated Balance Sheet, Statement of Operations and Cash Flows to Pro-forma Amounts

The following table compares the reported condensed consolidated balance sheet, statement of operations and cash flows, as of and for the three and nine months ended September 30, 2018 to the pro-forma amounts had the previous guidance (ASC 605) been in effect:

	As of September 30, 2018
	As Reported under ASC 606			Pro forma as if accounted for under ASC 605
Deferred revenue - related party		17,901			12,118
Deferred revenue, net of current portion - related party		89,554			76,034
Accumulated deficit		(368,083	)		(348,780	)

	Three Months Ended September 30, 2018						Nine Months Ended September 30, 2018
	As Reported under ASC 606			Pro forma as if accounted for under ASC 605			As Reported under ASC 606			Pro forma as if accounted for under ASC 605
Collaboration revenue - related party	$	8,684		$	3,084		$	16,721		$	9,167
Loss from operations		(22,211	)		(27,811	)		(78,613	)		(86,167	)
Net loss	$	(21,949	)	$	(27,549	)	$	(77,655	)	$	(85,209	)
Net loss per share attributable to common stockholders,    basic and diluted	$	(0.54	)	$	(0.68	)	$	(1.91	)	$	(2.09	)

	Nine Months Ended September 30, 2018
	As Reported under ASC 606			Pro forma as if accounted for under ASC 605
Net loss	$	(77,655	)	$	(85,209	)
Deferred revenue		(16,328	)		(8,774	)

Changes in Contract Liabilities

The following table presents changes in the Company’s contract liabilities during the nine months ended September 30, 2018 and 2017(in thousands):

	Balance as of January 1, 2018		Additions		Deductions			Balance as of September 30, 2018
Nine months ended September 30, 2018
Contract liabilities:
Deferred revenue		123,783		393		(16,721	)		107,455

	Balance as of January 1, 2017		Additions		Deductions			Balance as of September 30, 2017
Nine months ended September 30, 2017
Contract liabilities:
Deferred revenue		108,814		—		(9,044	)		99,770

During the three and nine months ended September 30, 2018 we recognized the following revenues as a result of changes in the the contract liability balances in the respective periods (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Revenue recognized in the period from:
Amounts included in the contract liability at the beginning    of the period		8,684		3,015		16,721		9,044