Income Per Share (Basic and Diluted Earnings Per Common Share) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended												4 Months Ended				12 Months Ended
	Sep. 08, 2012		Jun. 16, 2012		Mar. 24, 2012		Sep. 10, 2011		Jun. 18, 2011		Mar. 26, 2011		Dec. 29, 2012		Dec. 31, 2011		Dec. 29, 2012		Dec. 31, 2011		Jan. 01, 2011
Earnings Per Share [Abstract]
Income from continuing operations, net of tax (1)	$ 108.0		$ 121.7		$ 81.6		$ 130.3		$ 146.0		$ 25.1	[1]	$ 255.0	[2]	$ 216.8		$ 566.2		$ 518.2		$ 590.6
Noncontrolling interests																	(1.6)		(1.5)		(0.8)
Distributed and undistributed earnings allocated to participating securities																	(5.4)		(3.8)		0
Income from continuing operations available to common stockholders, diluted																	559.2		512.9		589.8
Income from continuing operations available to common stockholders, basic																	559.2		512.9		589.8
Gain from discontinued operations, net of tax	49.0	[3]	1.2	[3]	(8.6)	[3]							(9.6)	[3]			31.9	[2],[3]	0		0
Net income available to common stockholders after earnings allocated to participating securities, diluted																	591.1		512.9		589.8
Net income available to common stockholders after earnings allocated to participating securities, basic																	$ 591.1		$ 512.9		$ 589.8
Weighted-average common shares outstanding																	245.6		343.4		378.3
Common share equivalents																	0.3		0.4		1.3
Weighted average shares outstanding, diluted																	245.9		343.8		379.6
Continuing operations, Earnings per common share, diluted (usd per share)	$ 0.45		$ 0.50		$ 0.30								$ 1.06	[2]			$ 2.27		$ 1.49		$ 1.55
Continuing operations, Earnings per common share, basic (usd per share)	$ 0.45		$ 0.50		$ 0.30								$ 1.06	[2]			$ 2.28		$ 1.49		$ 1.56
Discontinued operations, Earnings per common share, diluted (usd per share)	$ 0.21	[3]	$ 0.01	[3]	$ (0.03)	[3]							$ (0.04)	[3]			$ 0.13	[2],[3]	$ 0.00		$ 0.00
Discontinued operations, Earnings per common share, basic (usd per share)	$ 0.21	[3]	$ 0.01	[3]	$ (0.03)	[3]							$ (0.04)	[3]			$ 0.13	[2],[3]	$ 0.00		$ 0.00
Total, Diluted (usd per share)	$ 0.66		$ 0.51		$ 0.27		$ 0.38	[3]	$ 0.41	[3]	$ 0.07	[1],[3]	$ 1.02	[2]	$ 0.67	[3]	$ 2.40		$ 1.49	[1],[3]	$ 1.55
Total, Basic (usd per share)	$ 0.66		$ 0.51		$ 0.27		$ 0.38	[3]	$ 0.42	[3]	$ 0.07	[1],[3]	$ 1.02	[2]	$ 0.67	[3]	$ 2.41		$ 1.49	[1],[3]	$ 1.56

[1] In the first quarter of 2011, Safeway incurred an estimated tax charge of $80.2 million as a result of the decision to repatriate $1.1 billion from Safeway's wholly-owned Canadian subsidiary.

[2] In the fourth quarter of 2012, Safeway results included a pre-tax gain from legal settlements of $46.5 million.

[3] See Note Q, Discontinued Operations.