Property and Equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 81,061	$ 43,741
Less accumulated depreciation	(29,201)	(26,218)
Net property and equipment	51,860	17,523
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	20,612	18,724
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,178	5,580
Construction in progress, gross	3,800
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	50,271	19,437
Construction in progress, gross	$ 30,500
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Construction in progress, gross		$ 3,800

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 of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

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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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