Income Taxes (Loss Carryforwards) (Details) - USD ($) $ in Millions	Apr. 30, 2022		Apr. 30, 2021
Operating Loss Carryforwards [Line Items]
Loss and Credit Carryforwards	$ 294		$ 327
Deferred Tax Assets, Loss and Credit Carryforwards	69		63
Loss and Credit Carryforwards, Valuation Allowance	(27)		(20)
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Loss and Credit Carryforwards	53		99
Deferred Tax Assets, Loss and Credit Carryforwards	19	[1]	15
Loss and Credit Carryforwards, Valuation Allowance	(8)		(5)
Domestic Tax Authority | Not Subject to Expiration [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Loss and Credit Carryforwards	8
Domestic Tax Authority | Subject to Expiration [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Loss and Credit Carryforwards	11
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Loss and Credit Carryforwards	241		228
Deferred Tax Assets, Loss and Credit Carryforwards	50	[2]	48
Loss and Credit Carryforwards, Valuation Allowance	(19)		$ (15)
Foreign Tax Authority [Member] | Not Subject to Expiration [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Loss and Credit Carryforwards	19
Foreign Tax Authority [Member] | Subject to Expiration [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Loss and Credit Carryforwards	$ 31

[1] As of April 30, 2022, the deferred tax asset amount includes credit carryforwards of $8 that do not expire and loss and credit carryforwards of $11 that expire in varying amounts from 2023 to 2039.

[2] As of April 30, 2022, the deferred tax asset includes loss carryforwards of $19 that do not expire and $31 that expire in varying amounts over the next 9 years.