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 expense recognized in the current period that allocates the cost of nonproduction tangible assets over their useful lives.

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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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Composition of Certain Financial Statement Captions (Property And Equipment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Property and Equipment [Line Items]
Property and Equipment, gross	$ 550,603		$ 550,603		$ 514,312
Less: Accumulated depreciation	(370,072)		(370,072)		(353,453)
Property and Equipment, net	180,531		180,531		160,859
Depreciation expense	7,945	$ 7,409	23,058	$ 22,162
Buildings
Property and Equipment [Line Items]
Property and Equipment, gross	162,999		162,999		162,882
Equipment
Property and Equipment [Line Items]
Property and Equipment, gross	134,827		134,827		123,945
Land
Property and Equipment [Line Items]
Property and Equipment, gross	10,830		10,830		10,830
Purchased software
Property and Equipment [Line Items]
Property and Equipment, gross	145,110		145,110		143,705
Furniture and fixtures
Property and Equipment [Line Items]
Property and Equipment, gross	20,726		20,726		18,835
Leasehold improvements
Property and Equipment [Line Items]
Property and Equipment, gross	20,712		20,712		20,700
Construction in progress
Property and Equipment [Line Items]
Property and Equipment, gross	$ 55,399		$ 55,399		$ 33,415