Summary of Impact of Translating Financial Statements (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Foreign Currency Translation [Line Items]
Total Assets of the Company's Subsidiaries	$ 3,857,199		$ 3,863,226
Other comprehensive Income (Loss)	1,586	15,799
Brazil
Foreign Currency Translation [Line Items]
Exchange Rate	2.03		2.05
Total Assets of the Company's Subsidiaries	334,374
Other comprehensive Income (Loss)	2,860
Mexico
Foreign Currency Translation [Line Items]
Exchange Rate	12.33		13.02
Total Assets of the Company's Subsidiaries	118,434
Other comprehensive Income (Loss)	4,821
Argentina
Foreign Currency Translation [Line Items]
Exchange Rate	5.14		4.91
Total Assets of the Company's Subsidiaries	129,019
Other comprehensive Income (Loss)	(4,294)
Colombia
Foreign Currency Translation [Line Items]
Exchange Rate	1,832.20		1,768.23
Total Assets of the Company's Subsidiaries	46,193
Other comprehensive Income (Loss)	(1,244)
Peru
Foreign Currency Translation [Line Items]
Exchange Rate	2.65		2.56
Total Assets of the Company's Subsidiaries	38,223
Other comprehensive Income (Loss)	(1,252)
All other
Foreign Currency Translation [Line Items]
Other comprehensive Income (Loss)	651
Total International Subsidiaries
Foreign Currency Translation [Line Items]
Other comprehensive Income (Loss)	$ 1,542