Fair Value Measurements (Details) - Fair Value, Measurements, Recurring [Member] - Estimate of Fair Value [Member] - USD ($) $ in Millions	Oct. 28, 2016	Jan. 29, 2016	Oct. 30, 2015
Short-term Investments [Member]
Assets, Fair Value Disclosure
Available-for-sale securities, fair value	$ 123	$ 307	$ 158
Short-term Investments [Member] | Certificates Of Deposit [Member] | Fair Value (Level 1) [Member]
Assets, Fair Value Disclosure
Available-for-sale securities, fair value	55	56	96
Short-term Investments [Member] | Municipal Obligations [Member] | Fair Value (Level 2) [Member]
Assets, Fair Value Disclosure
Available-for-sale securities, fair value	37	38	1
Short-term Investments [Member] | Money Market Funds [Member] | Fair Value (Level 1) [Member]
Assets, Fair Value Disclosure
Available-for-sale securities, fair value	28	192	50
Short-term Investments [Member] | Municipal Floating Rate Obligations [Member] | Fair Value (Level 2) [Member]
Assets, Fair Value Disclosure
Available-for-sale securities, fair value	3	21	11
Long-term Investments [Member]
Assets, Fair Value Disclosure
Available-for-sale securities, fair value	436	222	382
Long-term Investments [Member] | Certificates Of Deposit [Member] | Fair Value (Level 1) [Member]
Assets, Fair Value Disclosure
Available-for-sale securities, fair value	2	5	5
Long-term Investments [Member] | Municipal Obligations [Member] | Fair Value (Level 2) [Member]
Assets, Fair Value Disclosure
Available-for-sale securities, fair value	4	5	5
Long-term Investments [Member] | Municipal Floating Rate Obligations [Member] | Fair Value (Level 2) [Member]
Assets, Fair Value Disclosure
Available-for-sale securities, fair value	$ 430	$ 212	$ 372