Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 26, 2015	Jul. 27, 2014	Jul. 26, 2015	Jul. 27, 2014
Income Taxes
Income tax expense	$ 46	$ 27	$ 84	$ 53
Effective Income Tax Rate, Continuing Operations	64.00%	17.20%	34.30%	16.80%
Icera deferred tax asset write-off	$ 27
Tax benefit related to the restructuring charges	$ 13
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate			35.00%
Annual projected effective tax rate			22.20%