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		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Property and Equipment [Line Items]
Property and Equipment, gross	$ 549,950		$ 549,950		$ 514,312
Less: Accumulated depreciation	(367,677)		(367,677)		(353,453)
Property and Equipment, net	182,273		182,273		160,859
Depreciation expense	7,640	$ 7,422	15,113	$ 14,753
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	137,698		137,698		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	145,816		145,816		143,705
Furniture and fixtures
Property and Equipment [Line Items]
Property and Equipment, gross	20,032		20,032		18,835
Leasehold improvements
Property and Equipment [Line Items]
Property and Equipment, gross	20,109		20,109		20,700
Construction in progress
Property and Equipment [Line Items]
Property and Equipment, gross	$ 52,466		$ 52,466		$ 33,415