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v3.19.1

Segment and Geographic Information - Additional Information (Details) - Segment | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2018 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Operating Segments [Abstract] |  |  |  |
Number of operating segments | 2 |  |  |
Number of reportable segments |  | 2 |  |
Revenue | Customer concentration risk | Cisco Systems |  |  |  |
Disclosure of major customers [line items] |  |  |  |
Concentration risk percentage |  | 14.00% | 18.00% | 19.00%
Revenue | Customer concentration risk | Dell Inc |  |  |  |
Disclosure of major customers [line items] |  |  |  |
Concentration risk percentage |  | 10.00% |  |
Revenue | Customer concentration risk | Top two customers |  |  |  |
Disclosure of major customers [line items] |  |  |  |
Concentration risk percentage |  |  | 31.00% | 30.00%

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- Definition Concentration Risk, Percentage + References No definition available. + Details
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- Definition Number of Operating Segments1 + References No definition available. + Details
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- Definition Number of Reportable Segments + References No definition available. + Details
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- Definition Operating Segments [Abstract] + References No definition available. + Details
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- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table. + References No definition available. + Details
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- Details
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- Details
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- Details
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- Details
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