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Income Taxes - Additional Information (Detail) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2019 | Dec. 31, 2018
Income Tax Contingency [Line Items] |  |
Increase in effective tax rate due to GILTI provisions | 8.00% |
Valuation allowance with tax impact | $ 0.2 |
Gross unrecognized tax benefits | 29.9 | $ 29.6
Unrecognized tax benefits that would impact effective tax rate | $ 19.9 |
Maximum [Member] |  |
Income Tax Contingency [Line Items] |  |
Percentage of deduction in GILTI Income | 50.00% |
Gross unrecognized tax benefits balance may decrease within the next twelve months | $ 6.3 |
Minimum [Member] |  |
Income Tax Contingency [Line Items] |  |
Gross unrecognized tax benefits balance may decrease within the next twelve months | $ 0.0 |

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- Definition Tax cuts and jobs act of 2017 change in effective tax rate due to global intangible low-taxed income provisions. + References No definition available. + Details
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