Property and Equipment Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 155,267	$ 152,289
Accumulated depreciation and amortization	103,228	100,789
Total property and equipment, net	52,039	51,500
Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	76,668	75,417
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	8,122	7,844
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	16,381	16,274
Software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	42,305	42,048
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 11,791	$ 10,706

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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