Property and equipment, net - Property and equipment, net (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Property and equipment, net
Property and Equipment, gross	$ 455,533	$ 422,982
Less accumulated depreciation and amortization	(116,411)	(103,231)
Property and Equipment, net	339,122	319,751
Office equipment
Property and equipment, net
Property and Equipment, gross	15,240	16,955
Laboratory equipment
Property and equipment, net
Property and Equipment, gross	65,439	61,697
Computer equipment
Property and equipment, net
Property and Equipment, gross	56,687	55,436
Land
Property and equipment, net
Property and Equipment, gross	10,161	10,122
Building and leasehold improvements
Property and equipment, net
Property and Equipment, gross	211,346	213,196
Operating lease right-of-use assets
Property and equipment, net
Property and Equipment, gross	27,622
Construction in Progress
Property and equipment, net
Property and Equipment, gross	$ 69,038	$ 65,576

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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