Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
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Kolltan Acquisition - Acquisition Related Expenses, Including Severance (Details) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended
	Nov. 29, 2016	Dec. 31, 2016	Dec. 31, 2016
Acquisition related expenses, including severance
Acquisition-related expenses		$ 700	$ 700
Kolltan
Acquisition related expenses, including severance
Acquisition-related expenses	$ 3,768
Severance expense		$ 3,100
Kolltan \| General and administrative
Acquisition related expenses, including severance
Severance expense			2,400
Kolltan \| Research and development
Acquisition related expenses, including severance
Severance expense			$ 700