Property And Equipment (Schedule Of Property And Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 208,785	$ 175,831
Less: accumulated depreciation and amortization	(131,865)	(107,089)
Property and equipment, net	76,920	68,742
Computers and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	27,519	22,702
Software and software development costs
Property, Plant and Equipment [Line Items]
Property and equipment, gross	144,260	120,278
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	8,123	7,754
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 28,883	$ 25,097

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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