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Jurisdictions the Company Remains Subject to Tax Examinations (Detail) | 12 Months Ended
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Dec. 31, 2018
United States | Earliest Tax Year | Federal |
Income Taxes [Line Items] |
Tax Years | 2015
United States | Earliest Tax Year | State |
Income Taxes [Line Items] |
Tax Years | 2012
United States | Latest Tax Year | Federal |
Income Taxes [Line Items] |
Tax Years | 2018
United States | Latest Tax Year | State |
Income Taxes [Line Items] |
Tax Years | 2018
Ireland | Earliest Tax Year |
Income Taxes [Line Items] |
Tax Years | 2014
Ireland | Latest Tax Year |
Income Taxes [Line Items] |
Tax Years | 2018
United Kingdom | Earliest Tax Year |
Income Taxes [Line Items] |
Tax Years | 2017
United Kingdom | Latest Tax Year |
Income Taxes [Line Items] |
Tax Years | 2018

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