Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income tax expense (benefit) related to continuing operations	$ 28	$ (294)	$ 178	$ (158)
Reported income tax rates (percent)	4.30%	(30.30%)	13.70%	(45.00%)
Discrete tax benefit recognized due to temporary difference arising from buyer's excess tax basis	$ 105
Deferred tax asset for the 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	$ 1,000		$ 1,000
Unrecognized tax benefits that would reduce income tax expense and the effective tax rate	882		882
Possible decrease in unrecognized tax benefits during the next twelve months	$ 105		$ 105