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Retirement Plans - Additional Information (Detail) - USD ($)
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]      
Expected period of return on plan assets, years 10 years 10 years  
Minimum contribution by employer $ 0 $ 0 $ 0
Discretionary contributions by employer 0 0 0
Fair value of plan assets 219,400,000 207,800,000 207,500,000
Postretirement benefit obligation and unfunded status of plan 271,400,000 261,300,000 261,800,000
Net periodic postretirement benefit cost $ 2,700,000 3,000,000 2,800,000
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 $ 32,000,000 30,600,000 31,700,000
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 $ 51,600,000 47,700,000 42,500,000
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 $ 6,400,000 5,800,000 4,700,000
Fair value of plan assets 329,000,000 263,300,000  
Retiree Health Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Postretirement benefit obligation and unfunded status of plan 2,500,000 2,700,000  
Net periodic postretirement benefit cost $ (300,000) $ (300,000) $ (300,000)