Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2019	Apr. 30, 2019	Apr. 30, 2018
Effective Income Tax Rate Reconciliation, Percent		19.20%
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		$ 90
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
Foreign Earnings Repatriated	$ 120
Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act, Amount		$ 8
Scenario, Forecast [Member]
Expected Tax Rate on Ordinary Income			21.90%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21.00%
Predecessor [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%
Minimum [Member] | Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, Percent			19.00%
Maximum [Member] | Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, Percent			20.00%