Related Party Transactions - Textual (Details) - AstraZeneca [Member] - USD ($)	3 Months Ended
Mar. 31, 2018	Mar. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Accounts receivable from related parties		$ 0	$ 200,000
Revenue from related parties	$ 300,000

For an unclassified balance sheet, amount of receivables arising from transactions with related parties.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant