Quarterly report pursuant to Section 13 or 15(d)

Income Taxes - Additional Information (Detail)

v3.8.0.1
Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Dec. 31, 2015
Schedule Of Income Taxes [Line Items]            
Effective tax rate 9.40% 24.20% 12.90% 19.90%    
U.S. federal and state statutory rate     39.00%      
Cash and cash equivalents $ 802,932 $ 665,291 $ 802,932 $ 665,291 $ 718,536 $ 507,991
Non-US [Member]            
Schedule Of Income Taxes [Line Items]            
Cash and cash equivalents 503,100   $ 503,100      
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     62.70%      
Non-US [Member] | Funds Available For Repatriation [Member]            
Schedule Of Income Taxes [Line Items]            
Cash and cash equivalents 54,100   $ 54,100      
ASU 2016-09 [Member]            
Schedule Of Income Taxes [Line Items]            
Tax (expense) benefit from share-based compensation $ 200   $ 1,100      
Minimum [Member] | Non-U.S jurisdictions [Member]            
Schedule Of Income Taxes [Line Items]            
Statutory federal rate     0.00%      
Maximum [Member] | Non-U.S jurisdictions [Member]            
Schedule Of Income Taxes [Line Items]            
Statutory federal rate     34.00%