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Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer.

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The amount of expense provided in the period for legal costs incurred on or before the balance sheet date pertaining to resolved, pending or threatened litigation, including arbitration and mediation proceedings.

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Cash received on stock transaction after deduction of issuance costs.

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Related Party Transactions - Narrative (Details) - USD ($)	1 Months Ended		12 Months Ended
	Feb. 28, 2018	Feb. 15, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Accounts receivable			$ 337,000	$ 899,000
Affiliated Entity \| Covington
Related Party Transaction [Line Items]
Legal services			100,000	200,000	$ 200,000
Outstanding accounts payable balances			0	0
Equity Method Investee \| AstraZeneca
Related Party Transaction [Line Items]
Payments received			7,900,000	34,000,000	$ 1,100,000
Accounts receivable			$ 300,000	$ 900,000
Series G Redeemable Convertible Preferred Stock
Related Party Transaction [Line Items]
Shares of stock issued (in shares)	55,666,004	55,666,004
Price per share (usd per share)	$ 10.06	$ 10.06
Aggregate purchase price	$ 560,000,000	$ 560,000,000