Subsequent Event - Acquisition (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended		6 Months Ended
	Jun. 16, 2012	Dec. 31, 2011	Apr. 03, 2012	Jun. 16, 2012 No Frills Acquisition [Member]	Jun. 25, 2012 No Frills Acquisition [Member]
Business Acquisition, Effective Date of Acquisition	Apr. 03, 2012			Jun. 25, 2012
Business Acquisition, Name of Acquired Entity	Bag 'N Save Inc.			NF Foods, LLC
Business Acquisition, Cost of Acquired Entity, Cash Paid (in Dollars)			$ 29.7		$ 47.5
Retail Revenue (in Dollars)		$ 230.0