Accumulated Other Comprehensive Loss (Activity Associated With Accumulated Other Comprehensive Loss) (Details) (USD $) In Millions	6 Months Ended
	Jul. 30, 2011	Jul. 31, 2010
Accumulated other comprehensive loss, at beginning of period	$ (730)	$ (753)
Unrealized loss on marketable securities, net of income tax effect of $1 million and $1 million	(2)	(2)
Reclassification of realized gain on marketable securities to net income, net of income tax effect of $4 million	(8)	0
Recognition of net actuarial (gain) loss, net of income tax effect of $17 million and $12 million	28	18
Prior service cost, net of income tax effect of less than $1 million and less than $1 million	(1)	(1)
Accumulated other comprehensive loss, at end of period	(713)	(738)
Income tax effect of unrealized loss on marketable securities	1	1
Income tax effect of reclassification adjustment due to realized gain on marketable securities	4
Income tax effect of net actuarial (gain) loss	17	12
Maximum [Member]
Income tax effect of prior service cost	$ 1	$ 1