Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 34	$ 69	$ 296	$ 178
Effective tax rate	16.00%	24.00%	23.00%	26.00%
Deferred tax assets	$ 1,400		$ 1,400		$ 2,900
Net deferred income tax liability	$ 5,656		$ 5,656		$ 5,452

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences without jurisdictional netting.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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