Summary of Cumulative Trauma Product Liability Claims Activity (Detail)	12 Months Ended
	Dec. 31, 2013 LegalMatter	Dec. 31, 2012 LegalMatter	Dec. 31, 2011 LegalMatter
Loss Contingency, Quantities [Roll Forward]
Open claims, January 1	2,609	2,321	1,900
New lawsuits	489	750	479
Settled and dismissed lawsuits	(258)	(462)	(58)
Open claims, December 31	2,840	2,609	2,321