Property and Equipment, Net (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 230,584	$ 205,852
Less: accumulated depreciation and amortization	(115,066)	(129,576)
Property and equipment, net	115,518	76,276
Depreciation and amortization expense	29,500	31,100	$ 27,700
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	19,226	17,712
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	172,679	161,019
Telecommunications equipment and other
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,862	5,642
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 34,817	$ 21,479

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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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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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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