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Pension And Postretirement Benefits (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended
Oct. 27, 2019
Oct. 28, 2018
Pension Plan, Defined Benefit [Member]    
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement $ (1) $ 0