Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended							1 Months Ended	6 Months Ended		1 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012 Antitrust Lawsuits Defendant	Jun. 30, 2012 Antitrust Lawsuits Canada	Jun. 30, 2011 Antitrust Lawsuits Canada Defendant	Jun. 30, 2012 Antitrust Lawsuits Punitive Damages Canada	Jun. 30, 2011 Antitrust Lawsuits Direct Purchaser Class Action Cases	Jun. 30, 2011 Antitrust Lawsuits Individual Direct Purchaser Cases	Apr. 16, 2009 Brazilian Value- Added Tax Matters	Jun. 30, 2012 Brazilian Value- Added Tax Matters	Jun. 30, 2012 Brazilian Value- Added Tax Matters Tax Credit Matters	Jan. 24, 2012 Patent Infringement Claim	Jun. 30, 2012 Patent Infringement Claim	Jun. 30, 2011 Patent Infringement Claim
Commitments And Contingencies [Line Items]
Charges against earnings	$ 0
Number of defendants		20		15
Named as a defendant in pending cases			2			3	29
General and special damages			100.0		10.0			3.3	4.0	1.0	5.0
Number of patents infringed													3
Alleged damages amount												$ 16.2