Segments and Geographic Area Analysis - Revenues by Geographic Area Presented by Attributing Revenues to Individual Country (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 706,165	$ 729,141	$ 2,193,924	$ 2,235,971
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	69,627	49,443	253,654	146,009
South America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	311,708	360,617	896,029	1,084,210
Europe/Africa/Mediterranean [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	185,335	162,324	559,290	484,229
Australia/Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	88,054	111,850	333,728	379,240
Mexico [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 51,441	$ 44,907	$ 151,223	$ 142,283