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Retirement Plans - Additional Information (Detail) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items] |  |  |
Expected period of return on plan assets, years | 10 years | 10 years |
Minimum contribution by employer | $ 30,000,000 | $ 0 | $ 0
Discretionary contributions by employer | 30,000,000 | 0 | 0
Fair value of plan assets | 220,000,000 | 219,400,000 | 207,800,000
Postretirement benefit obligation and unfunded status of plan | 253,200,000 | 271,400,000 | 261,300,000
Net periodic postretirement benefit cost | $ (1,000,000) | 2,700,000 | 3,000,000
Foreign Retirement Plans [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Percentage of eligible compensation for matching contributions by employer | 5.00% |  |
Contribution expense to plan | $ 34,900,000 | 32,000,000 | 30,600,000
Matching contributions by employer, percentage | 100.00% |  |
Additional percentage of eligible compensation for matching contributions by employer | 5.00% |  |
Qualified Contributory Savings and Thrift 401(k) Plan [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Percentage of eligible compensation for matching contributions by employer | 5.00% |  |
Contribution expense to plan | $ 53,900,000 | 51,600,000 | 47,700,000
Matching contributions by employer, percentage | 100.00% |  |
Matching contributions vesting schedule | 5 years |  |
Nonqualified Deferred Compensation Plan [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Percentage of eligible compensation for matching contributions by employer | 5.00% |  |
Contribution expense to plan | $ 6,500,000 | 6,400,000 | 5,800,000
Fair value of plan assets | 355,000,000 | 329,000,000 |
Retiree Health Plan [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Postretirement benefit obligation and unfunded status of plan | 2,000,000 | 2,500,000 |
Net periodic postretirement benefit cost | $ (300,000) | $ (300,000) | $ (300,000)

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