Consolidated Statements of Changes in Common Stockholders' Investment - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		May 31, 2020		Aug. 31, 2019		May 31, 2019		Aug. 31, 2018		May 31, 2020	May 31, 2019	May 31, 2018
Beginning Balance				$ 17,757				$ 19,416		$ 17,757	$ 19,416	$ 16,073
Net income		$ (334)	[1],[2]	745	[1],[2]	$ (1,969)	[3],[4]	835	[3],[4]	1,286	540	4,572
Other comprehensive loss, net of tax										(333)	(287)	(163)
Purchase of treasury stock										(3)	(1,480)	(1,017)
Cash dividends declared										(679)	(683)	(535)
Employee incentive plans and other										220	251	486
Ending Balance		18,295				17,757				18,295	17,757	19,416
Accounting Standards Update 2016-02 and 2018-02
Adoption of new accounting standards on June 1, 2019	[5]									(4)
Accounting Standards Update 2018-02
Reclassification to retained earnings due to the adoption of a new accounting standard on June 1, 2019	[6]									51
Common Stock
Beginning Balance				32				32		32	32	32
Ending Balance		32				32				32	32	32
Additional Paid-In Capital
Beginning Balance				3,231				3,117		3,231	3,117	3,005
Employee incentive plans and other										125	114	112
Ending Balance		3,356				3,231				3,356	3,231	3,117
Retained Earnings
Beginning Balance				24,648				24,823		24,648	24,823	20,833
Net income										1,286	540	4,572
Cash dividends declared										(679)	(683)	(535)
Employee incentive plans and other										(35)	(32)	(47)
Ending Balance		25,216				24,648				25,216	24,648	24,823
Retained Earnings | Accounting Standards Update 2016-02 and 2018-02
Adoption of new accounting standards on June 1, 2019	[5]									(4)
Accumulated Other Comprehensive Loss
Beginning Balance				(865)				(578)		(865)	(578)	(415)
Other comprehensive loss, net of tax										(333)	(287)	(163)
Ending Balance		(1,147)				(865)				(1,147)	(865)	(578)
Accumulated Other Comprehensive Loss | Accounting Standards Update 2018-02
Reclassification to retained earnings due to the adoption of a new accounting standard on June 1, 2019	[6]									51
Treasury Stock
Beginning Balance				$ (9,289)				$ (7,978)		(9,289)	(7,978)	(7,382)
Purchase of treasury stock										(3)	(1,480)	(1,017)
Employee incentive plans and other										130	169	421
Ending Balance		$ (9,162)				$ (9,289)				$ (9,162)	$ (9,289)	$ (7,978)

[1] The fourth quarter of 2020 includes a tax benefit of $71 million in connection with the 2020 U.S. tax loss that can be offset against income in prior years under the CARES Act and a tax expense of $51 million due to a change in deferred tax balances related to foreign tax operations. The second quarter of 2020 includes a tax benefit of $133 million from the reduction of a valuation allowance on certain foreign tax loss carryforwards.

[2] The fourth quarter, third quarter, second quarter and first quarter of 2020 include $63 million, $72 million, $64 million and $71 million, respectively, of TNT Express integration expenses. The fourth quarter includes $369 million of goodwill and other asset impairment charges associated with the FedEx Office and FedEx Logistics operating segments and a net loss of $794 million related to the annual MTM retirement plans accounting adjustment. The second quarter of 2020 includes asset impairment charges of $66 million related to the permanent retirement of 10 Airbus A310-300 aircraft and 12 related engines at FedEx Express.

[3] The fourth quarter, third quarter, second quarter and first quarter of 2019 include $84 million, $69 million, $114 million and $121 million, respectively, of TNT Express integration expenses (including any restructuring charges). The fourth quarter and third quarter of 2019 include business realignment costs of $316 million and $4 million, respectively. The fourth quarter includes a net loss of $3.9 billion related to the annual MTM retirement plans accounting adjustment. The second quarter of 2019 includes costs incurred in connection with the settlement of a legal matter involving FedEx Ground of $46 million.

[4] The third quarter of 2019 includes a tax benefit of $90 million from the reduction of a valuation allowance on certain tax loss carryforwards and a tax expense of $50 million related to a lower tax rate in the Netherlands applied to our deferred tax balances. The second quarter of 2019 includes a tax benefit of approximately $60 million from accelerated deductions claimed on our 2018 U.S. income tax return. In addition, we recognized a tax expense of $4 million in the second quarter of 2019 as a revision of the provisional benefit associated with the remeasurement of our net U.S. deferred tax liability upon completion of the accounting for the tax effects of the TCJA.

[5] ^{Relates to the adoption of Accounting Standards Update (“ASU”) 2016-02 and ASU 2018-02}

[6] ^{Relates to the adoption of ASU 2018-02.}