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Income Taxes - Additional Information (Detail) - USD ($) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Income Tax Contingency [Line Items] |  |  |  |  |
Corporate income tax rate |  |  | 35.00% | 35.00% | 35.00%
Provisional Income tax expense | $ 81,800,000 |  | $ 81,800,000 |  |
Income tax expense related to one time mandatory tax | 83,500,000 |  |  |  |
Income tax expense due to tax rate reform | 1,700,000 |  |  |  |
Total taxes paid |  |  | 131,100,000 | $ 117,400,000 | $ 97,500,000
Cash and cash equivalents and marketable securities were held by foreign subsidiaries |  |  | 815,200,000 |  |
Unrecognized tax benefits that would affect the effective tax rate, if recognized | 600,000 |  | 600,000 |  |
Anticipated decrease in unrecognized tax benefits | 0 |  | $ 0 |  |
State and local | Earliest Tax Year |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Income tax examinations, years under examination |  |  | 2001 |  |
State and local | Latest Tax Year |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Income tax examinations, years under examination |  |  | 2017 |  |
Non-U.S. | Earliest Tax Year |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Income tax examinations, years under examination |  |  | 2009 |  |
Non-U.S. | Latest Tax Year |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Income tax examinations, years under examination |  |  | 2017 |  |
U.S. federal | Earliest Tax Year |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Income tax examinations, years under examination |  |  | 2015 |  |
U.S. federal | Latest Tax Year |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Income tax examinations, years under examination |  |  | 2017 |  |
Scenario, Forecast |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Corporate income tax rate |  | 21.00% |  |  |
Discontinued Operations |  |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |  |
Additional income tax accrual | $ 38,600,000 |  | $ 38,600,000 |  |

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