Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Acquisition (Intangible Assets) (Details) - Quarton - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jan. 02, 2019
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross					$ 22,200
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life				2 years 9 months 18 days
Amortization of Intangible Assets	$ 2,200	$ 6,700	$ 2,200	$ 6,700
Trade name
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross					900
Finite-Lived Intangible Asset, Useful Life				3 years
Customer relationships
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross					7,100
Finite-Lived Intangible Asset, Useful Life				4 years
Backlog
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross					12,600
Finite-Lived Intangible Asset, Useful Life				2 years
Proprietary software
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Gross					$ 1,600
Finite-Lived Intangible Asset, Useful Life				3 years