Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v3.10.0.1
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
Schedule Of Income Taxes [Line Items]          
Maximum measurement period to complete accounting   1 year      
Tax cuts and jobs act of 2017, incomplete accounting, provisional income tax expense (benefit) $ 99,900,000 $ 89,000,000 $ 99,900,000    
Reduction in provisional tax   $ 10,900,000      
U.S. federal and state statutory rate   26.00%      
Income (loss) before income taxes   $ 431,884,000 384,260,000 $ 359,484,000  
Income tax expense   $ 60,611,000 $ 149,156,000 $ 74,125,000  
Effective tax rate   14.00% 38.80% 20.60%  
Foreign tax benefit   $ 49,111,000 $ 35,549,000 $ 29,471,000  
Prior year tax refunds received   3,400,000      
Cash and cash equivalents 736,431,000 872,237,000 736,431,000 718,536,000 $ 507,991,000
Cumulative total earnings   522,200,000      
Increase in valuation allowance   2,900,000      
Increase in unrecognized tax benefits   600,000      
Unrecognized tax benefits that would be recorded as reduction in income tax expense if recognized   8,000,000      
Interest and penalties   200,000 500,000 400,000  
Accrued interest and penalties 1,500,000 1,800,000 1,500,000    
Prior year unrecognized tax benefits by result of expiring statutes   512,000 355,000    
Reduction in prior period unrecognized tax benefits   0      
Income Tax Examination [Member]          
Schedule Of Income Taxes [Line Items]          
Reasonably possible decrease in unrecognized tax benefits in next twelve month   900,000      
Non-US [Member]          
Schedule Of Income Taxes [Line Items]          
Cash and cash equivalents   $ 522,200,000      
Non-US [Member] | Geographic concentration risk [Member] | Cash and Cash Equivalents Geographical Area [Member]          
Schedule Of Income Taxes [Line Items]          
Percentage of cash and cash equivalents   59.90%      
Non-US [Member] | Funds Available For Repatriation [Member]          
Schedule Of Income Taxes [Line Items]          
Cash and cash equivalents   $ 276,900,000      
Non-U.S jurisdictions [Member]          
Schedule Of Income Taxes [Line Items]          
Income (loss) before income taxes   $ 415,300,000      
Average income tax rate   11.80%      
Income tax expense   $ 49,100,000      
Income before income taxes relates to foreign losses   11,200,000      
Foreign tax benefit   0      
Net operating loss carry-forwards 94,900,000 121,500,000 94,900,000    
Valuation allowance against deferred tax assets 21,400,000 21,400,000 21,400,000    
U.S Jurisdictions [Member]          
Schedule Of Income Taxes [Line Items]          
Income (loss) before income taxes   $ 16,597,000 25,628,000 105,589,000  
Average income tax rate   69.00%      
Income tax expense   $ 11,500,000 113,607,000 44,654,000  
Jersey [Member]          
Schedule Of Income Taxes [Line Items]          
Income (loss) before income taxes   213,327,000 198,048,000 146,880,000  
Increase in earnings before income taxes   15,300,000      
Other jurisdictions [Member]          
Schedule Of Income Taxes [Line Items]          
Income (loss) before income taxes   75,601,000 64,488,000 35,464,000  
Income tax expense   24,797,000 14,242,000 $ 12,533,000  
State [Member]          
Schedule Of Income Taxes [Line Items]          
Tax credits due to operating loss carried back 6,600,000 8,900,000 6,600,000    
Net operating loss carry-forwards 31,300,000 31,100,000 31,300,000    
Valuation allowance against deferred tax assets $ 0 $ 0 $ 0    
Tax credit and operating loss carry-forward expiration, description   These tax credit and net operating loss carry-forward amounts do not begin to expire until 2032 and 2025, respectively.      
Domestic and Foreign [Member] | Settlement with Taxing Authority [Member]          
Schedule Of Income Taxes [Line Items]          
Reasonably possible decrease in unrecognized tax benefits in next twelve month   $ 800,000      
Minimum [Member] | Non-U.S jurisdictions [Member]          
Schedule Of Income Taxes [Line Items]          
Statutory federal rate   0.00%      
Minimum [Member] | Other jurisdictions [Member]          
Schedule Of Income Taxes [Line Items]          
Consolidated earnings (loss) before taxes, percent   5.00%      
Maximum [Member] | Non-U.S jurisdictions [Member]          
Schedule Of Income Taxes [Line Items]          
Statutory federal rate   34.60%