Commitments - Schedule of Aircraft Purchase Commitments (Details)	9 Months Ended
Feb. 28, 2022 AirCraft
Schedule of Aircraft Commitments [Line Items]
2022 (remainder)	11
2023	33
2024	36
2025	30
2026	12
Total	122
Cessna SkyCourier 408 [Member]
Schedule of Aircraft Commitments [Line Items]
2022 (remainder)	3
2023	12
2024	12
2025	12
2026	11
Total	50
ATR 72-600F [Member]
Schedule of Aircraft Commitments [Line Items]
2022 (remainder)	5
2023	6
2024	6
2025	6
2026	1
Total	24
B767F [Member]
Schedule of Aircraft Commitments [Line Items]
2022 (remainder)	3
2023	13
2024	14
2025	10
Total	40
B777F [Member]
Schedule of Aircraft Commitments [Line Items]
2023	2
2024	4
2025	2
Total	8

The total number of aircraft committed to be purchased.

No definition available.

Name:	fdx_AircraftPurchaseObligation
Namespace Prefix:	fdx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Aircraft purchase obligation with delivery due in first fiscal year.

No definition available.

Name:	fdx_AircraftPurchaseObligationWithDeliveryDueInFirstFiscalYear
Namespace Prefix:	fdx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The number of aircraft committed to be purchased with a delivery date in the fourth fiscal year.

No definition available.

Name:	fdx_AircraftPurchaseObligationWithDeliveryDueInFourthFiscalYear
Namespace Prefix:	fdx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The number of aircraft committed to be purchased with a delivery date in the second fiscal year.

No definition available.

Name:	fdx_AircraftPurchaseObligationWithDeliveryDueInSecondFiscalYear
Namespace Prefix:	fdx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The number of aircraft committed to be purchased with a delivery date in the third fiscal year.

No definition available.

Name:	fdx_AircraftPurchaseObligationWithDeliveryDueInThirdFiscalYear
Namespace Prefix:	fdx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Aircraft purchase obligation with delivery within remainder of fiscal year.

No definition available.

Name:	fdx_AircraftPurchaseObligationWithDeliveryWithinRemainderOfFiscalYear
Namespace Prefix:	fdx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Schedule of Aircraft Commitments [Line Items]

No definition available.

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Namespace Prefix:	fdx_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

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Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=fdx_ATR72600FreighterMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=fdx_Boeing767FreighterMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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Namespace Prefix:
Data Type:	na
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Period Type: