Stockholders' Equity Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
	May 01, 2019	Oct. 31, 2019	Jul. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (363)		$ (363)			$ (363)
Adoption of ASU 2018-02 (Note 1)	(43)
Net other comprehensive income (loss)		$ 7	(1)	$ (1)	$ 14	6	$ 13
Ending balance		(400)				(400)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(207)		(207)			(207)
Adoption of ASU 2018-02 (Note 1)	(1)
Net other comprehensive income (loss)		11		(27)		(3)	(39)
Ending balance		(211)				(211)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	31		31			31
Adoption of ASU 2018-02 (Note 1)	(1)
Net other comprehensive income (loss)		(7)		22		2	45
Ending balance		32				32
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(187)		(187)			(187)
Adoption of ASU 2018-02 (Note 1)	(41)
Net other comprehensive income (loss)		3		4		7	$ 7
Ending balance		(221)				$ (221)
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)		$ 7	$ (1)	$ (1)	$ 14