Income Taxes - Differences between Total Income Tax Expense and Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Computed “expected” Federal income tax expense	$ 20,081	$ 34,277	$ 49,578
(Decrease) increase in income taxes resulting from:
State income taxes, net	1,331	637	7,975
Foreign non-taxed income, rate differential	(2,076)	(7,609)	(5,453)
Other adjustments, net	18,869	(143)	(3,531)
Total income tax expense (benefit)	$ 38,205	$ 27,162	$ 48,569