Stockholders' Equity Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended
	May 01, 2019	Jul. 31, 2019	Jul. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (363)	$ (363)
Adoption of ASU 2018-02 (Note 1)	(43)
Net other comprehensive income (loss)		(1)	$ 14
Ending balance		(407)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(207)	(207)
Adoption of ASU 2018-02 (Note 1)	(1)
Net other comprehensive income (loss)		(13)	(12)
Ending balance		(221)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	31	31
Adoption of ASU 2018-02 (Note 1)	(1)
Net other comprehensive income (loss)		9	23
Ending balance		39
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(187)	(187)
Adoption of ASU 2018-02 (Note 1)	(41)
Net other comprehensive income (loss)		3	3
Ending balance		(225)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Adoption of ASU 2018-02 (Note 1)	$ (43)
Net other comprehensive income (loss)		$ (1)	$ 14