Retirement Plans - Additional Information (Details) - USD ($)	12 Months Ended
	May 31, 2024	May 31, 2023	May 31, 2022	May 31, 2021	May 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Weighted average discount rate percent all pension postretirement plans		5.17%	4.21%	3.11%	3.05%
U.S. pension plan actual rate of return on assets		(2.70%)	(10.80%)	12.90%
401(k)-plan description		In 2020, we announced the closing of our U.S.-based defined benefit pension plans to new non-union employees hired on or after January 1, 2020. We introduced an all-401(k) plan retirement benefit structure for eligible employees with a higher company match of up to 8% across all U.S.-based operating companies in 2022. During calendar 2021, current eligible employees under the PPA pension formula were given a one-time option to continue to be eligible for pension compensation credits under the existing PPA formula and remain in the existing 401(k) plan with its company match of up to 3.5%, or to cease receiving compensation credits under the PPA and move to the new 401(k) plan with the higher match of up to 8%. Changes to the new 401(k) plan structure became effective January 1, 2022. See Note 1 for additional information on expected amendments to our pension plan offered to FedEx Express pilots.
Actual rate of return on plan assets for the 15-year period		5.70%
Amounts recognized in other comprehensive income primarily related to amortization of prior service cost, net of tax		$ 10,000,000	$ 8,000,000	$ 7,000,000
Defined benefit plan health care cost trend rate assumed for next fiscal year		6.40%
Defined benefit plan ultimate health care cost trend rate		4.00%
Defined benefit plan year that rate reaches ultimate trend rate		2045
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return on assets		6.50%	6.50%	6.75%
Pension Plans [Member] | U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return on assets		6.50%	6.50%	6.75%
Defined benefit plan contributions by employer		$ 826,000,000	$ 533,000,000
Amounts recognized in other comprehensive income primarily related to amortization of prior service cost		7,000,000	7,000,000
Amounts recognized in other comprehensive income primarily related to amortization of prior service cost, net of tax		$ 6,000,000	$ 6,000,000
Pension Plans [Member] | U.S. Plans [Member] | Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer	$ 0
Future Plan Structure [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Company matching contributions to eligible employees		8.00%
Current Plan Structure [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Company matching contributions to eligible employees		3.50%
Voluntary Contribution [Member] | U.S. Plans [Member] | Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer	$ 800,000,000