Supplemental Financial Information - Currency Transaction Gains (Losses) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Currency Transaction Gains (Losses) [Line Items]
Net transaction (losses) gains	$ (191,332)	$ (34,006)	$ 46,887
Operating income
Currency Transaction Gains (Losses) [Line Items]
Net transaction (losses) gains	(164,042)	(25,715)	44,060
Other non-operating (expense) income, net
Currency Transaction Gains (Losses) [Line Items]
Net transaction (losses) gains	$ (27,290)	$ (8,291)	$ 2,827