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Income Taxes - Additional Information (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Income Tax Expense Benefit [Line Items] |  |  |  |
Earnings (losses) before income taxes, foreign |  | $ 99.5 | $ 5.6 | $ (52.1)
Interest expense, foreign deposits |  | 64.2 | 110.7 | 107.0
Interest expense, domestic deposits |  | 64.2 | 110.7 | $ 107.0
Net unrecognized tax benefits |  | 9.0 | 10.0 |
Accrued interest and penalties related to unrecognized tax benefits |  | 2.9 | 2.8 |
Deferred tax liabilities |  | 332.0 | 371.1 |
Undistributed earnings of foreign subsidiaries |  | $ 330.0 | 243.0 |
Unrecognized deferred tax liability on undistributed earnings |  |  | $ 15.6 |
Federal statutory rate |  | 35.00% | 35.00% | 35.00%
Deferred income taxes |  | $ 905.1 | $ 796.5 |
U.S. repatriation tax rate |  | 9.70% |  |
U.S. repatriation tax amount |  | $ 36.8 |  |
Noncurrent Liabilities [Member] |  |  |  |
Income Tax Expense Benefit [Line Items] |  |  |  |
Deferred tax liabilities |  | 332.0 | $ 371.1 |
Deferred minimum tax credits |  | 108.2 |  |
General Business Tax Credits [Member] |  |  |  |
Income Tax Expense Benefit [Line Items] |  |  |  |
Deferred tax credits |  | $ 571.6 |  |
Deferred tax credits expiration year |  | 2034 |  |
State Tax Credits [Member] |  |  |  |
Income Tax Expense Benefit [Line Items] |  |  |  |
Deferred tax credits |  | $ 3.5 |  |
Deferred tax credits expiration year |  | 2021 |  |
HR One [Member] |  |  |  |
Income Tax Expense Benefit [Line Items] |  |  |  |
Deferred income taxes |  | $ 1.0 |  |
U.S. repatriation tax rate |  | 10.00% |  |
U.S. repatriation tax amount |  | $ 40.0 |  |
Scenario, Forecast [Member] |  |  |  |
Income Tax Expense Benefit [Line Items] |  |  |  |
Federal statutory rate | 21.00% |  |  |

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