Asset acquisition.

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Asset purchase agreement closing date.

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Business acquisition equity interests issued or issuable upon achievement of development and regulatory milestones.

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Business combination recognized identifiable assets acquired and liabilities assumed fixed assets.

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Percentage of nonmonetary exchange of shares.

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- Definition

Stock issued for period shares issued for research and development licensing fee satisfied with stock.

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- Definition

Stock issued for period value issued for research and development licensing fee satisfied with stock.

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- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Fair value of the entity's equity.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Percentage investment held by members or limited partners of limited liability company (LLC) or limited partnership (LP).

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The amount of capital contributed by the limited partners.

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The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands			3 Months Ended			9 Months Ended		12 Months Ended
	Jun. 27, 2019	Jun. 29, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Asset Acquisition [Line Items]
Goodwill			$ 37,293			$ 37,293		$ 37,495
Research and development licensing fee satisfied with stock				$ 29,545	$ 2,000
Research and development expenses			19,588	$ 51,202		62,570	$ 99,077
Axis Therapeutics Limited
Asset Acquisition [Line Items]
Capital contributions to joint venture		$ 30,000	30,000			$ 30,000
Percentage of ownership in joint venture		55.00%				55.00%
Axis Therapeutics Limited \| Research and Development Expenses
Asset Acquisition [Line Items]
Research and development expenses								$ 24,500
Axis Therapeutics Limited \| Licensing Agreements
Asset Acquisition [Line Items]
Research and development licensing fee satisfied with stock, shares		267,952
Research and development licensing fee satisfied with stock		$ 5,000
Axis Therapeutics Limited \| XLifeSc \| IPR & D
Asset Acquisition [Line Items]
Percentage of ownership in joint venture		45.00%
Percentage of nonmonetary exchange of shares						45.00%
Fair value of equity shares issued			$ 24,500			$ 24,500
Common Stock
Asset Acquisition [Line Items]
Research and development licensing fee satisfied with stock, shares				267,952	107,181
CIDAL Limited
Asset Acquisition [Line Items]
Asset purchase agreement closing date	Oct. 31, 2019
Purchase price	$ 2,200
Liabilities assumed	1,100
Contingent consideration paid	1,100
Cash received	800
Goodwill	1,400
CIDAL Limited \| Maximum [Member]
Asset Acquisition [Line Items]
Fixed assets	$ 100
CIDAL Limited \| Common Stock
Asset Acquisition [Line Items]
Business acquisition, assumed liabilities and milestone payments aggregate share consideration	67,796