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	6 Months Ended
	Jun. 14, 2014	Jun. 15, 2013	Dec. 28, 2013	Jun. 14, 2014	Jun. 15, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales and other revenue	$ 82.4	$ 2,068.6		$ 312.9	$ 4,067.4
Income (loss) from discontinued operations, before income taxes	0.2	83.2		(67.3)	148.5
(Loss) gain on sale or disposal of operations, net of lease exit costs and transaction costs, before income taxes	7.8	0		44.9	0
Total income (loss) from discontinued operations before income taxes	8.0	83.2		(22.4)	148.5
Income taxes on discontinued operations	7.0	(136.9)		22.5	(143.0)
Income (loss) from discontinued operations, net of tax	15.0	(53.7)		0.1	5.5
Blackhawk [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales and other revenue	82.4	212.7		305.6	388.4
Income (loss) from discontinued operations, before income taxes	1.3	5.5		(4.4)	5.8
(Loss) gain on sale or disposal of operations, net of lease exit costs and transaction costs, before income taxes	(5.5)	0		(5.5)	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	1,522.3		0	3,015.5
Income (loss) from discontinued operations, before income taxes	0	87.4		0	163.7
(Loss) gain on sale or disposal of operations, net of lease exit costs and transaction costs, before income taxes	(0.2)	0		(5.2)	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	333.6		7.3	663.5
Income (loss) from discontinued operations, before income taxes	(1.1)	(9.7)		(62.9)	(21.0)
(Loss) gain on sale or disposal of operations, net of lease exit costs and transaction costs, before income taxes	$ 13.5	$ 0	$ (493.1)	$ 55.6	$ 0