Assets and Liabilities Held for Sale and Discontinued Operations (Financial Results of Discontinued Operations) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		4 Months Ended	9 Months Ended
	Sep. 06, 2014	Sep. 07, 2013	Dec. 28, 2013	Sep. 06, 2014	Sep. 07, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales and other revenue	$ 0	$ 1,976.9		$ 312.9	$ 6,044.3
(Loss) income from discontinued operations, before income taxes:	(2.9)	64.9		(70.1)	213.4
Gain (loss) on sale or disposal of operations, net of lease exit costs and transaction costs, before income taxes:	25.1	0		69.9	0
Total income (loss) from discontinued operations before income taxes	22.2	64.9		(0.2)	213.4
Income tax benefit (expense) on discontinued operations	8.5	(21.9)		31.1	(164.9)
Income from discontinued operations, net of tax	30.7	43.0		30.9	48.5
Blackhawk [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales and other revenue	0	194.4		305.6	582.8
(Loss) income from discontinued operations, before income taxes:	0	3.8		(4.4)	9.6
Gain (loss) on sale or disposal of operations, net of lease exit costs and transaction costs, before income taxes:	0.3	0		(5.2)	0
Canada Safeway Limited [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales and other revenue	0	1,454.1		0	4,469.6
(Loss) income from discontinued operations, before income taxes:	0	74.5		0	238.2
Gain (loss) on sale or disposal of operations, net of lease exit costs and transaction costs, before income taxes:	(1.2)	0		(6.4)	0
Dominick's Stores [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales and other revenue	0	328.4		7.3	991.9
(Loss) income from discontinued operations, before income taxes:	(2.9)	(13.4)		(65.7)	(34.4)
Gain (loss) on sale or disposal of operations, net of lease exit costs and transaction costs, before income taxes:	$ 26.0	$ 0	$ (493.1)	$ 81.5	$ 0