Stockholders' Equity Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Jul. 31, 2021	Jul. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (422)
Net other comprehensive income (loss)	8	$ 24
Ending balance	(414)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(179)
Net other comprehensive income (loss)	(10)	62
Ending balance	(189)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(16)
Net other comprehensive income (loss)	14	(45)
Ending balance	(2)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(227)
Net other comprehensive income (loss)	4	7
Ending balance	(223)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net other comprehensive income (loss)	$ 8	$ 24