The maximum annual amount of funding for research activities through 2017 per the amended agreement.

No definition available.

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The maximum amount of cost reimbursement the Company will receive on a annual basis.

+ References

No definition available.

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The current portion of deferred revenue from related parties as of balance sheet date. Current deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized, and is expected to be recognized in the next twelve months. Generally, an entity records deferred revenue when it receives consideration before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References

No definition available.

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- Definition

Our share of profits/losses related to commercialization of products by our collaborator based on sales outside the United States. Under the terms of our collaboration agreement, we share profits/losses with our collaborator on commercialization of products.

+ References

No definition available.

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- Definition

The percentage of subsequent Shared Phase 3 Trial costs borne by the collaborating party upon receipt of the first positive Phase 3 trial results for a co-developed drug candidate.

+ References

No definition available.

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The percentage of subsequent Shared Phase 3 Trial costs borne by the Company upon receipt of the first positive Phase 3 trial results for a co-developed drug candidate.

+ References

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Amount of revenue earned from products sold or services provided under the terms of a contract, including, but not limited to, government contracts and construction contracts, classified as other.

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Amount of deferred revenue recognized for transactions arising during the current reporting period. Deferred revenue is a liability as of the balance sheet date related to a revenue producing activity for which revenue has not yet been recognized. Generally, an Entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References

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Repayment received or receivable for expenses incurred on behalf of a client or customer, other than those reimbursements received by landlords from tenants.

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The amount of compensation earned (contract income) under a research and development arrangement accounted for as a contract to perform research and development for others.

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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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Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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Collaboration Agreements (Sanofi) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2017	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2016
Collaboration Agreement [Line Items]
Revenue from Related Parties		$ 245,175	$ 144,392			$ 677,670	$ 527,500
Research and development		529,749	543,047			1,547,159	1,573,089
Deferred Revenue From Related Party Current		187,036				187,036			$ 115,267
Antibody Collaboration
Collaboration Agreement [Line Items]
Net profit (loss) from commercialization of products under collaboration agreement		(98,315)	(112,001)			(328,998)	(333,530)
Reimbursement of Regeneron research and development expenses		128,539	131,389			421,056	469,223
Reimbursement Revenue		90,339	64,418			251,002	213,957
Contracts Revenue		41,848	4,360			84,338	19,999
Revenue from Related Parties		162,411	88,166			$ 427,398	369,649
Percentage of Trial Costs borne by collaborating party						80.00%
Percentage of Trial Costs borne by entity						20.00%
IO Discovery Agreement
Collaboration Agreement [Line Items]
Annual Funding Maximum of Research Activities Per Agreement						$ 200,000
IO Agreement
Collaboration Agreement [Line Items]
Deferred Revenue, Additions					$ 640,000
Immuno-oncology Agreement
Collaboration Agreement [Line Items]
Reimbursement of Regeneron research and development expenses		61,649	36,226			188,408	97,851
Contracts Revenue		21,115	20,000			61,864	60,000
Revenue from Related Parties		82,764	56,226			250,272	157,851
Praluent, Kevzara, and Dupixent [Member] [Member] \| Antibody Collaboration
Collaboration Agreement [Line Items]
Research and development		$ 22,600	$ 27,900			$ 68,200	$ 80,200
Scenario, Forecast [Member] \| Antibody Collaboration
Collaboration Agreement [Line Items]
Annual funding maximum of research activities per amended agreement								$ 130,000
Mitsubishi Tanabe Pharma Corporation (MTPC) [Member] \| Collaborative Arrangement [Member]
Collaboration Agreement [Line Items]
Deferred Revenue, Additions	$ 10,000
Additional payments received [Member] [Member] \| Mitsubishi Tanabe Pharma Corporation (MTPC) [Member] \| Collaborative Arrangement [Member]
Collaboration Agreement [Line Items]
Deferred Revenue, Additions				$ 60,000