Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
	Jan. 31, 2019	Oct. 31, 2018	Apr. 30, 2019	Apr. 30, 2018
Expected Tax Rate on Ordinary Income		21.40%
Effective Income Tax Rate Reconciliation, Percent		18.60%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%		30.40%
Income Tax Benefit from Reduction in Federal Statutory Income Tax Rate		$ 60
Tax Cuts and Jobs Act, Incomplete Accounting, Provisional Income Tax Expense (Benefit)				$ 43
Tax Cuts and Jobs Act, Incomplete Accounting, Transition Tax for Accumulated Foreign Earnings, Provisional Income Tax Expense				91
Tax Cuts and Jobs Act, Incomplete Accounting, Change in Tax Rate, Provisional Income Tax Expense (Benefit)				$ (48)
Tax Cuts and Jobs Act, Incomplete Accounting, Measurement Period Adjustment, Provisional Income Tax Expense (Benefit)		4
Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act, Amount		$ 7
Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21.00%
Foreign Earnings Repatriated	$ 120
Predecessor [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%