Accumulated Other Comprehensive Loss (Activity Associated With Accumulated Other Comprehensive Loss) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Oct. 29, 2011	Oct. 30, 2010
Accumulated Other Comprehensive Loss [Abstract]
Accumulated other comprehensive loss, at beginning of period	$ (730)	$ (753)
Unrealized loss on marketable securities, net of income tax effect of $1 million and $0 million	(2)	0
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 $26 million and $17 million	42	27
Prior service cost, net of income tax effect of $1 million and $1 million	(1)	(1)
Accumulated other comprehensive loss, at end of period	(699)	(727)
Income tax effect of unrealized loss on marketable securities	1	0
Income tax effect of reclassification adjustment due to realized gain on marketable securities	4
Income tax effect of net actuarial (gain) loss	26	17
Income tax effect of prior service cost	$ 1	$ 1