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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Composition of Certain Financial Statement Captions (Property And Equipment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Property and Equipment [Line Items]
Property and Equipment, gross	$ 578,785		$ 578,785		$ 567,691
Less: Accumulated depreciation	(394,743)		(394,743)		(378,639)
Property and Equipment, net	184,042		184,042		189,052
Depreciation expense	8,424	$ 7,640	16,733	$ 15,113
Buildings
Property and Equipment [Line Items]
Property and Equipment, gross	210,053		210,053		206,151
Equipment
Property and Equipment [Line Items]
Property and Equipment, gross	147,224		147,224		141,820
Land
Property and Equipment [Line Items]
Property and Equipment, gross	24,344		24,344		24,179
Purchased software
Property and Equipment [Line Items]
Property and Equipment, gross	152,259		152,259		147,838
Furniture and fixtures
Property and Equipment [Line Items]
Property and Equipment, gross	21,535		21,535		21,439
Leasehold improvements
Property and Equipment [Line Items]
Property and Equipment, gross	22,246		22,246		21,604
Construction in progress
Property and Equipment [Line Items]
Property and Equipment, gross	$ 1,124		$ 1,124		$ 4,660