ORGANIZATION - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	9 Months Ended		1 Months Ended			1 Months Ended
	Jan. 24, 2012 Ratio	Sep. 29, 2012 Store	Dec. 31, 2011	Feb. 29, 2012 IPO [Member]	Feb. 07, 2012 IPO [Member]	Feb. 13, 2012 IPO [Member]	Feb. 29, 2012 Existing Shareholders [Member] IPO [Member]	Feb. 29, 2012 Roundy [Member] IPO [Member]	Sep. 29, 2012 Wisconsin [Member] Store	Sep. 29, 2012 Minnesota [Member] Store	Sep. 29, 2012 Illinois [Member] Store
Subsidiary, Sale of Stock [Line Items]
Retail grocery stores		160							121	32	7
Initial public offering priced date		Feb. 07, 2012
Common stock offered				22,059,091	14,706		7,353,208	14,705,883
Common stock per share						$ 8.50
Gross proceeds from IPO				$ 125.0
Net proceeds after deducting the underwriting discount and expenses				$ 111.9
Common stock authorized	150,000,000	150,000,000	150,000,000
Preferred stock authorized	5,000,000
Stock split on common shares outstanding	292
Preferred stock reflected as having been converted and then subsequently split			10,439