Basis of Presentation - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Jan. 03, 2012
Number of weeks in a quarter for financial reporting purposes	13- or 14-week quarter
Date of completion of acquisition of business	Jan. 03, 2012
Total consideration of the acquisition	$ 346,440	$ 346,400
Date of completion of sale of business	May 06, 2011