Geographic Information on Revenues from External Customers (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from External Customers	$ 27,745.5	$ 20,169.7	$ 16,895.2
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from External Customers	18,184.0	14,386.6	11,855.9
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from External Customers	1,180.3	809.3	652.5
Malaysia
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from External Customers	2,063.0	1,793.8	1,526.4
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from External Customers	6,144.8	3,018.7	2,838.7
Republic of the Congo
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from External Customers	148.8	156.5	16.5
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from External Customers	$ 24.6	$ 4.8	$ 5.2