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No definition available.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

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The cumulative amount of the reporting entity's undistributed earnings or deficit.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014	Jan. 01, 2018
Revenue
Accumulated Deficit	$ (962,438)	$ (812,517)
Deferred Revenue	1,586	2,813
Accounts receivable	3,162	1,880
Revenue recognized from contract liabilities	1,900
Revenues	9,538	12,743	$ 6,786
ASU 2014-09
Revenue
Accumulated Deficit					$ (1,300)
Deferred Revenue					(800)
Accounts receivable					$ 500
Product Development and Licensing Agreements
Revenue
Revenues	3,341	3,153	2,174
Contracts and Grants
Revenue
Revenues	6,197	9,590	4,612
Bristol-Myers Squibb Company \| Product Development and Licensing Agreements
Revenue
Deferred Revenue				$ 5,000
Reimbursement of external costs (as percent)				50.00%
Revenues	3,300	2,800	2,100
IAVI & Frontier \| Contracts and Grants
Revenue
Revenues	3,000	6,600
Rockefeller \| Contracts and Grants
Revenue
Revenues	$ 2,600	$ 2,200	$ 2,700