Performance Contingent ROIC Shares (Detail) (Grant Date Seven July Two Thousand And Twelve, Return On Invested Capital, USD $)	9 Months Ended
	Oct. 06, 2012
Grant Date Seven July Two Thousand And Twelve | Return On Invested Capital
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	137,500
Approximate vesting date	Feb. 28, 2014
Fair value per share	$ 21.56