XML 62 R50.htm IDEA: XBRL DOCUMENT v3.3.1.900
Financial Instruments - Narrative (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jan. 29, 2016
Jan. 23, 2015
Jan. 29, 2016
Jan. 23, 2015
Apr. 24, 2015
Schedule of Investments [Line Items]          
Marketable securities $ 14,692   $ 14,692   $ 14,746
Cost 524   524   520
Other expense, net [Member]          
Schedule of Investments [Line Items]          
Impairment, cost method investments 2 $ 1 23 $ 14  
Other assets [Member]          
Schedule of Investments [Line Items]          
Marketable securities 202   202   186
Cost 524   524   520
Debt securities [Member]          
Schedule of Investments [Line Items]          
Credit loss portion of other-than-temporary impairments 0   0   0
Reductions for available-for-sale securities sold 0 0 0 0  
Other-than-temporary impairment losses on available-for-sale securities 0 $ 0 0 0  
Marketable equity securities [Member] | Other expense, net [Member]          
Schedule of Investments [Line Items]          
Impairment charges, marketable securities 0   20 $ 7  
Marketable equity securities [Member] | Other assets [Member]          
Schedule of Investments [Line Items]          
Marketable securities $ 96   $ 96   $ 80