Financing Agreements - Additional Information (Detail) In Millions, unless otherwise specified	1 Months Ended	6 Months Ended			6 Months Ended					6 Months Ended
	Jan. 31, 2011 Senior Notes USD ($)	Jun. 30, 2012 Senior Notes USD ($)	Jan. 31, 2011 Senior Notes Due 2019 USD ($)	Jan. 31, 2011 Senior Notes Due 2021 USD ($)	Jun. 30, 2012 Revolving Facility USD ($)	Jun. 30, 2012 Revolving Facility Minimum	Jun. 30, 2012 Revolving Facility Maximum	Jun. 30, 2012 Revolving Facility Letter of Credit	Jun. 30, 2012 Revolving Facility Letter of Credit Maximum USD ($)	Jun. 30, 2012 European Receivables Loan Facility USD ($)	Jun. 30, 2012 European Receivables Loan Facility EUR (€)	Jun. 30, 2012 Covenant Requirement Green Zone Minimum USD ($)	Jun. 30, 2012 Covenant Requirement Yellow Zone CreditScore	Jun. 30, 2012 Covenant Requirement Yellow Zone Minimum USD ($)
Debt Instrument [Line Items]
Net proceeds of the offerings	$ 733
Cash and cash equivalents paid for debt extinguishment	127
Senior notes issued			400	350
Senior notes issued, interest rate			6.50%	6.75%
Gross borrowings		750
Weighted-average interest rate on the Senior Notes		6.62%
Interest payment dates		February 15 and August 15 of each year
Current aggregate facility					500				300	95	75
Percentage of applicable commitment fee						0.50%	0.625%
Percentage of fronting fee								0.25%
Utilized letters of credit					67
Borrowing base collateral					460
Available borrowing capacity					393					95
Revolving facility expiration					Feb. 29, 2016					Mar. 31, 2016	Mar. 31, 2016
Borrowings					0					0	0
Pro forma excess borrowing availability												$ 125		$ 75
Fixed charge coverage ratio													1.1
Debt covenants, description					The incurrence-based covenants in the revolving facility permit us to, among other things, (i) issue foreign subsidiary indebtedness, (ii) incur general secured indebtedness and (iii) incur additional unsecured debt so long as the pro forma minimum fixed charge coverage ratio is at least 1.11.0.
Debt covenants, dividend payment conditions					We may also make dividend payments in respect of our common stock as well as certain investments and acquisitions so long as there is (i) at least $125 of pro forma excess borrowing availability or (ii) at least $75 of pro forma excess borrowing availability and the pro forma minimum fixed charge coverage ratio is at least 1.11.0.