Description of Business Segments and Summary of Significant Accounting Policies - Additional Information (Details) $ / shares in Units, € in Millions, $ in Millions		1 Months Ended	3 Months Ended	12 Months Ended			29 Months Ended
	Jun. 14, 2022 $ / shares	Jan. 31, 2021 Employee	Feb. 28, 2022 shares	May 31, 2022 USD ($) AirCraft $ / shares shares	May 31, 2021 USD ($) $ / shares	May 31, 2020 USD ($) AirCraft $ / shares shares	May 31, 2023 USD ($)	May 31, 2022 EUR (€) AirCraft shares	Dec. 16, 2021 USD ($)	Dec. 08, 2021 USD ($)	Jan. 26, 2016 shares
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Gross contract assets related to in-transit shipments				$ 861	$ 715
Contract assets net of deferred unearned revenue				623	572
Contract liabilities related to advance payments from customers				$ 8	9
Payment terms of customer contracts				Under the typical payment terms of our customer contracts, the customer pays at periodic intervals (e.g., every 15 days, 30 days, 45 days, etc.) for shipments included on invoices received. It is not customary business practice to extend payment terms past 90 days, and as such, we do not have a practice of including a significant financing component within our revenue contracts with customers.
Advertising and promotion expenses				$ 470	428	$ 427
Depreciable life range for majority of aircraft costs				15 to 30 years
Depreciation expense, excluding gains and losses on sales of property and equipment				$ 3,970	3,793	3,615
Interest costs capitalized				$ 62	68	$ 54
Number of aircraft to be permanently retired from service | AirCraft						10
Number of aircraft engines to be permanently retired from service | AirCraft						12
Noncash impairment charges						$ 66
Noncash impairment charges net of tax						$ 50
Noncash impairment charges net of tax per diluted share | $ / shares						$ 0.19
Number of Idle Aircraft | AirCraft				8				8
Number of months aircraft remained idle				an average of 24 months
Denominated debt as a net investment hedge | €								€ 107
Number of shares repurchased | shares				8,900,000		20,000.00
Treasury stock acquired, average cost per share | $ / shares				$ 253.85		$ 156.90
Payments for repurchase of common stock				$ 2,248		$ 3
Business realignment costs				$ 278	116
Number of employees left or voluntarily leaving | Employee		5,000
Restructuring plan execution period				2023
Business realignment costs, net of tax				$ 214	$ 90
Business realignment costs per diluted share | $ / shares				$ 0.80	$ 0.33
Business employee severance costs paid				$ 225	$ 15
Subsequent Event [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Cash dividend payable amount per share | $ / shares	$ 1.15
Cash dividend payable, date declared	Jun. 14, 2022
Cash dividend payable, date of record	Jun. 27, 2022
Cash dividend payable, date to be paid	Jul. 11, 2022
Equity and Commercial Agreements | Delhivery
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Equity investment										$ 100
2016 Repurchase Program
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Stock repurchase program number of shares authorized to be repurchased | shares											25,000,000
Stock repurchase program, remaining number of shares authorized to be available for repurchase | shares				0				0
2022 Repurchase Program
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Stock repurchase program amount authorized to be repurchased, remaining available amount				$ 4,100
Stock repurchase program amount authorized to be repurchased									$ 5,000
Accelerated Share Repurchase Agreement
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Stock repurchase program amount authorized to be repurchased									$ 1,500
Number of shares repurchased | shares			6,100,000
Forecast [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Business realignment costs							$ 420
Minimum [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Intangible assets amortization periods				1 year
Maximum [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Intangible assets amortization periods				15 years