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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No definition available.

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- Definition

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to intangibles acquired in connection with a business combination for which the initial accounting was incomplete.

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- Definition

The amount of identifiable intangible assets recognized as of the acquisition date.

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- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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- Definition

Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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Acquisitions - ObjectVideo (Details) - USD ($) $ in Thousands		3 Months Ended
	Jan. 01, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill			$ 63,591	$ 24,723	$ 24,723
ObjectVideo
Business Acquisition [Line Items]
Cash paid to acquire business	$ 6,000
Goodwill	2,258
Decrease in goodwill due to working capital adjustment		$ (400)
Developed Technology \| ObjectVideo
Business Acquisition [Line Items]
Increase to intangible assets		$ 400
Intangible assets acquired	$ 3,800
Weighted-average estimated useful life of intangible assets acquired (years)	2 years