Annual report pursuant to Section 13 and 15(d)

Income Taxes - Summary of Earnings before Income Taxes (Detail)

v3.8.0.1
Income Taxes - Summary of Earnings before Income Taxes (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Tax Disclosure [Abstract]      
Expected income tax expense $ 134,491 $ 125,819 $ 116,724
State income tax, net of federal benefit 297 2,335 2,011
Rate differential on foreign income (95,565) (58,508) (44,541)
Change in unrecognized tax benefits 1,449 135 (2,233)
Non-deductible expenses 4,451 2,330 (350)
Excess tax benefit on share based compensation (2,571)    
U.S. tax rate change 1,923    
U.S. transition tax 98,015    
Other (1,120) 575 285
Change in valuation allowance 7,786 1,439 554
Total income taxes (benefit) $ 149,156 $ 74,125 $ 72,450
Effective tax rate 38.80% 20.60% 21.70%