Property and equipment, net - Buildings and construction (Details) $ in Thousands	1 Months Ended	6 Months Ended
	Jul. 31, 2018 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jun. 30, 2019 USD ($)	Feb. 28, 2018 ft²
Property and equipment, net
Finance lease right-of-use assets, net		$ 28,133	$ 29,058
Costs for architectural and engineering studies and initial ground preparation		584,213	499,437
Construction in Progress
Property and equipment, net
Costs for architectural and engineering studies and initial ground preparation		$ 196,850	$ 116,387
Office Building in Morges, Switzerland
Property and equipment, net
Initial lease term					15 years
Options to extend		true
Renewal term of agreement to rent					20 years
Square footage | ft²					100,000
Financing lease liabilities				$ 31,100
Finance lease right-of-use assets, net				29,100
Finance Lease, Lease Incentive Receivable				$ 2,000
Site preparation, design and construction costs		$ 22,400
Land in Y-PARC, Switzerland's largest technology park, Yverdon
Property and equipment, net
Purchase price	$ 4,800
Land in Y-PARC, Switzerland's largest technology park, Yverdon | Construction in Progress
Property and equipment, net
Costs for architectural and engineering studies and initial ground preparation		$ 127,400