Required period of written notification to lessor prior to early termination required by terms of the lease agreement.

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- Definition

Number Of Operating Leases

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- Definition

Number of terms

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No definition available.

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- Definition

Percent Of Market Rate

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- Definition

Area of a real estate property.

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No definition available.

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- Definition

Amount of interest expense on finance lease liability.

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- Definition

Term of lessee's finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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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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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease.

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease having initial or remaining lease term in excess of one year to be paid in remainder of current fiscal year.

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- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

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Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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- Definition

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

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Amount of operating lease expense. Excludes sublease income.

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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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Leases - Narrative (Details) $ in Thousands		3 Months Ended		9 Months Ended
Leases - Narrative (Details) $ in Thousands	Jun. 19, 2020	Sep. 30, 2020 USD ($) ft² lease item	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) ft² lease item	Sep. 30, 2019 USD ($)	May 01, 2020 ft²	Dec. 31, 2019 ft²
Lessee, Lease, Description [Line Items]
Number of operating leases \| lease		3		3
Operating lease, expense		$ 5,200	$ 1,700	$ 10,200	$ 3,800
Finance lease expense		$ 500		$ 500
Renewal Term ( in years )		10 years		10 years
Aggregate rent, Initial term		$ 146,516		$ 146,516
2020 (excludes the nine months ended September 30, 2020)		2,842		2,842
2021		13,472		13,472
2022		13,229		13,229
Fixed lease cost		4,097	1,431	7,896	3,078
Research and development		$ 92,998	$ 63,076	$ 359,630	$ 175,621
MassBio
Lessee, Lease, Description [Line Items]
Written notice required for early lease termination	24 months
Lessee, Finance Lease, Term of Contract		12 years 6 months		12 years 6 months
Research and development		$ 41,400		$ 41,400
Minimum
Lessee, Lease, Description [Line Items]
Term of Contract ( in years )		3 months 18 days		3 months 18 days
Maximum
Lessee, Lease, Description [Line Items]
Term of Contract ( in years )		6 years 10 months 24 days		6 years 10 months 24 days
New Building
Lessee, Lease, Description [Line Items]
Area of real estate property \| ft²		75,000		75,000
Renewal Term ( in years )		10 years		10 years
Hopewell Campus
Lessee, Lease, Description [Line Items]
Term of Contract ( in years )		15 years		15 years
Area of real estate property \| ft²							220,500
Number of terms \| item		2		2
Aggregate rent, Initial term		$ 111,500		$ 111,500
Percent of market rate		95.00%		95.00%
Mountainview
Lessee, Lease, Description [Line Items]
2020 (excludes the nine months ended September 30, 2020)		$ 400		$ 400
2021		1,800		1,800
2022		$ 1,400		$ 1,400
Bridgewater
Lessee, Lease, Description [Line Items]
Area of real estate property \| ft²						59,000