Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income tax expense (benefit) related to continuing operations	$ 132	$ 28	$ 158	$ 178
Reported income tax expense (benefit) rates (percent)	29.90%	4.30%	15.70%	13.70%
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Charge for remeasurement to fair value			$ 470	$ 0
Discrete tax benefit recognized due to GILTI	$ 55
Discrete tax benefit recognized due to temporary difference arising from buyer's excess tax basis		$ 105		$ 105
Effect of discrete tax benefit on reported income tax rates (percent)		16.00%		8.10%
Unrecognized tax benefits	1,700		1,700
Unrecognized tax benefits that would reduce income tax expense and the effective tax rate	$ 1,300		1,300
Discrete tax benefit recognized			97
European Businesses (Disposal Group)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Charge for remeasurement to fair value			$ 491