Leases - Narrative (Details) € in Millions	1 Months Ended									12 Months Ended			22 Months Ended
	Apr. 30, 2022 USD ($) ft²	Dec. 31, 2021 USD ($)	Dec. 31, 2021 EUR (€)	Nov. 30, 2021 ft² $ / ft²	Oct. 31, 2021 USD ($) ft²	Feb. 28, 2021 USD ($)	Jul. 31, 2020 USD ($)	Mar. 31, 2020 EUR (€)	Apr. 30, 2019 USD ($) ft²	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Nov. 30, 2016	Jun. 30, 2016
Lessee, Lease, Description [Line Items]
Lease arrangements annual rent increase percentage									3.00%
Operating lease, expense										$ 36,200,000	$ 24,200,000	$ 23,300,000
60 Binney Street lease
Lessee, Lease, Description [Line Items]
Collateralized letter of credit					$ 13,800,000
Market capitalization required for release of liability					$ 900,000,000
Lease building space (in sq ft) | ft²					72,988
Lessee, operating lease, monthly expense					$ 500,000
60 Binney Street lease | Forecast
Lessee, Lease, Description [Line Items]
Lease building space (in sq ft) | ft²	58,004
Lessee, operating lease, monthly expense	$ 400,000
50 Binney Street sublease
Lessee, Lease, Description [Line Items]
Collateralized letter of credit		$ 40,100,000							$ 40,100,000
Lease building space (in sq ft) | ft²									267,278
Rate of area for sublease per square feet (in dollars per sq ft)									99.95
Lessee, operating lease, annual expense									$ 26,700,000
Lease arrangements annual rent increase percentage		3.00%								3.00%
Lessee, operating sublease, payment commencement, term									90 days
Upfront payment for purchase of furniture and equipment		$ 7,500,000							$ 7,500,000	$ 7,500,000
Payment for purchase of furniture and equipment, upon lease commencement									$ 7,500,000
Annual base rent of sub-sublease		28,000,000								28,000,000
50 Binney Street sublease | Selling, general and administrative
Lessee, Lease, Description [Line Items]
Loss on unrecoverable upfront payment		$ 7,500,000
Assembly Row lease
Lessee, Lease, Description [Line Items]
Lease building space (in sq ft) | ft²				61,180
Annual lease rent per square foot (in dollars per sq ft) | $ / ft²				45
Lease rent, annual increase percentage				2.50%
Tenant work allowance (in dollars per sq ft) | $ / ft²				160
Manufacturing Facility
Lessee, Lease, Description [Line Items]
Lessee, operating lease, annual expense										$ 5,100,000
Lease period						5 years	5 years							5 years	12 years
Milestone paid													$ 12,000,000
Lease extension terms														3 years
Lessee, operating lease, termination fees, term										24 months
Lessee, operating lease, maximum potential annual maintenance and production fees | €								€ 16.5
Lessee, operating lease, termination notice period						18 months	18 months	12 months
Payment of termination fee | €			€ 1.0
Lessee, operating lease, maximum potential annual maintenance fees						$ 4,200,000	$ 5,400,000
Lessee, operating lease, termination notice period, after stage 5 commencement						8 months