Fair Value Measurements (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Millions, unless otherwise specified	Jan. 26, 2014	Jan. 27, 2013
Total [Member]
Assets:
Foreign exchange derivative assets	$ 43	$ 20
Total	2,217	2,229
Total [Member] | Money market funds [Member]
Assets:
Investment securities	1,267	1,095
Total [Member] | U.S. Treasury and agency securities [Member]
Assets:
Investment securities	74	170
Total [Member] | Non-US government securities [Member]
Assets:
Investment securities	14	11
Total [Member] | Municipal securities [Member]
Assets:
Investment securities	387	386
Total [Member] | Commercial paper, corporate bonds and medium-term notes [Member]
Assets:
Investment securities	149	219
Total [Member] | Asset-backed Securities [Member]
Assets:
Investment securities	233	268
Total [Member] | Publicly traded equity securities [Member]
Assets:
Investment securities	50	60
Level 1 [Member]
Assets:
Foreign exchange derivative assets	0	0
Total	1,350	1,221
Level 1 [Member] | Money market funds [Member]
Assets:
Investment securities	1,267	1,095
Level 1 [Member] | U.S. Treasury and agency securities [Member]
Assets:
Investment securities	33	66
Level 1 [Member] | Non-US government securities [Member]
Assets:
Investment securities	0	0
Level 1 [Member] | Municipal securities [Member]
Assets:
Investment securities	0	0
Level 1 [Member] | Commercial paper, corporate bonds and medium-term notes [Member]
Assets:
Investment securities	0	0
Level 1 [Member] | Asset-backed Securities [Member]
Assets:
Investment securities	0	0
Level 1 [Member] | Publicly traded equity securities [Member]
Assets:
Investment securities	50	60
Level 2 [Member]
Assets:
Foreign exchange derivative assets	43	20
Total	867	1,008
Level 2 [Member] | Money market funds [Member]
Assets:
Investment securities	0	0
Level 2 [Member] | U.S. Treasury and agency securities [Member]
Assets:
Investment securities	41	104
Level 2 [Member] | Non-US government securities [Member]
Assets:
Investment securities	14	11
Level 2 [Member] | Municipal securities [Member]
Assets:
Investment securities	387	386
Level 2 [Member] | Commercial paper, corporate bonds and medium-term notes [Member]
Assets:
Investment securities	149	219
Level 2 [Member] | Asset-backed Securities [Member]
Assets:
Investment securities	233	268
Level 2 [Member] | Publicly traded equity securities [Member]
Assets:
Investment securities	$ 0	$ 0