Segments and Geographic Area Analysis - Countries Where Parent Company had Material Concentration of Operating Assets (Detail)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Brazil [Member]
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]
Percentage of material concentration of operating assets	37.30%	41.90%	52.70%
South Korea [Member]
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]
Percentage of material concentration of operating assets	15.20%	10.50%
United States [Member]
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]
Percentage of material concentration of operating assets	9.10%	6.10%	14.90%
Republic of Congo [Member]
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]
Percentage of material concentration of operating assets	7.40%		9.30%
Indonesia [Member]
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]
Percentage of material concentration of operating assets	6.80%	3.40%	3.80%
Mexico [Member]
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]
Percentage of material concentration of operating assets	6.50%	7.30%	0.90%
Egypt [Member]
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]
Percentage of material concentration of operating assets	4.70%	5.50%	6.30%
Vietnam [Member]
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]
Percentage of material concentration of operating assets	1.40%	6.60%	0.60%
Angola [Member]
Entity Wide Disclosure On Geographic Areas Countries Where Parent Company Had Material Concentration Of Operating Assets [Line Items]
Percentage of material concentration of operating assets		8.00%	1.70%