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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services 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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Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 68,696	$ 57,522
Less accumulated depreciation and amortization	(18,402)	(15,818)
Property and equipment, net	50,294	41,704
Depreciation expense	3,700	3,800	$ 4,000
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	15,734	11,051
Buildings
Property, Plant and Equipment [Line Items]
Property and equipment, gross	25,283	23,749
Land
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,479	5,930
Land Improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,195	6,906
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,341	1,435
Furniture, fixtures and other
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 8,664	$ 8,451