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.

+ References

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services 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
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Property and Equipment [Line Items]
Property and Equipment, gross	$ 462,525		$ 456,383
Less: Accumulated depreciation	(317,245)		(309,955)
Property and Equipment, net	145,280		146,428
Depreciation expense	7,122	$ 6,800
Building [Member]
Property and Equipment [Line Items]
Property and Equipment, gross	154,007		153,961
Equipment [Member]
Property and Equipment [Line Items]
Property and Equipment, gross	118,823		115,546
Land [Member]
Property and Equipment [Line Items]
Property and Equipment, gross	10,557		10,030
Purchased Software [Member]
Property and Equipment [Line Items]
Property and Equipment, gross	136,226		134,610
Furniture and Fixtures [Member]
Property and Equipment [Line Items]
Property and Equipment, gross	18,320		18,114
Leasehold Improvements [Member]
Property and Equipment [Line Items]
Property and Equipment, gross	18,851		18,017
Construction in Progress [Member]
Property and Equipment [Line Items]
Property and Equipment, gross	$ 5,741		$ 6,105