WORLDWIDE PANDEMIC - Narrative (Details) $ in Millions				12 Months Ended			24 Months Ended
	Dec. 31, 2022 USD ($) employee	Dec. 31, 2021 USD ($)	Jun. 01, 2020	Dec. 31, 2022 USD ($) employee	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2021 employee
Unusual or Infrequent Item, or Both [Line Items]
Extended emergency time off accrual for employees who accepted through 2020				$ 109
COVID - 19
Unusual or Infrequent Item, or Both [Line Items]
Voluntary separation program 2020 participants | employee	4,200			4,200
Number of employees who participated in extended emergency time off during 2020 | employee							12,000
Extended emergency time off accrual for employees who accepted through 2020	$ 219	$ 328			$ 446	$ 1,400
Extended emergency time off reversal for employees who accepted through March 31, 2021				$ 140
Proceeds from PSP2 payroll support program					$ 2,700
COVID - 19 | Minimum
Unusual or Infrequent Item, or Both [Line Items]
Extended emergency time off, period			6 months
COVID - 19 | Maximum
Unusual or Infrequent Item, or Both [Line Items]
Extended emergency time off, period			18 months
COVID - 19 | Maximum | Pilots
Unusual or Infrequent Item, or Both [Line Items]
Extended emergency time off, period			5 years