Income Taxes (Detail) - USD ($) $ in Millions	6 Months Ended
Nov. 30, 2019	Nov. 30, 2018	May 31, 2019
Income Tax Disclosure [Abstract]
Federal income tax rate	11.70%	14.50%
Total gross unrecognized tax benefits, excluding related interest and penalties	$ 804		$ 808
Total gross unrecognized tax benefits, excluding related interest and penalties, amount which would affect the Company's effective tax rate if recognized in future periods	545
Increase (decrease) in liability for payment of interest and penalties	(30)
Accrued interest and penalties related to uncertain tax positions (excluding federal benefit)	144		$ 174
Estimated decrease in total gross unrecognized tax benefits as a result of resolutions of global tax examinations and expiration of applicable statutes of limitations	$ 50

Amount of decrease reasonably possible in the next twelve months for the unrecognized tax benefit.

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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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The amount the liability recorded for the income tax examination increased or decreased in the current year/accounting period.

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Amount of unrecognized tax benefits.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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