Short-Term Borrowings and Credit Lines - Additional Information (Detail) - USD ($)	Mar. 15, 2021	Aug. 16, 2019	May 31, 2021	Feb. 28, 2021	May 31, 2020	Apr. 06, 2020	Aug. 28, 2015
Short-term Debt [Line Items]
Notes payable			$ 2,000,000		$ 248,000,000
Revolving Credit Facility
Short-term Debt [Line Items]
Borrowing capacity		$ 2,000,000,000					$ 2,000,000,000
Maximum borrowing capacity, additional amount		$ 3,000,000,000
Line of credit facility extension period after maturity		1 year
Revolving credit facility, fee		0.04%
Line of Credit
Short-term Debt [Line Items]
Borrowing capacity	$ 1,000,000,000					$ 2,000,000,000
Basis spread on variable rate, above LIBOR	0.50%
Revolving credit facility, fee	0.03%
Extension term	364 days
Extension term, period prior to termination	30 days
Commercial paper
Short-term Debt [Line Items]
Borrowing capacity	$ 3,000,000,000			$ 4,000,000,000
Notes payable			0		248,000,000
London Interbank Offered Rate (LIBOR) | Revolving Credit Facility
Short-term Debt [Line Items]
Basis spread on variable rate, above LIBOR		0.46%
Option To Increase Upon Lender Approval | Line of Credit
Short-term Debt [Line Items]
Borrowing capacity	$ 1,500,000,000
Committed Credit Facility, Maturing April 5, 2021 | Line of Credit
Short-term Debt [Line Items]
Notes payable			$ 0		$ 0