Investments - Narrative (Details)	1 Months Ended		3 Months Ended			12 Months Ended
	May 31, 2020 USD ($) aircraft	Jan. 31, 2020 USD ($) aircraft joint_venture_party $ / shares	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) aircraft	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2015 USD ($)
Schedule of Equity Method Investments [Line Items]
Short-term investments							$ 5,789,000,000	$ 0
Short-term investments expected to mature in one year or less							4,900,000,000
Restructuring charges							8,219,000,000	0	$ 0
Impairments and equity method losses							2,432,000,000	62,000,000	60,000,000
Long-term investments							1,417,000,000	1,099,000,000
Net gain (loss) on investments							(105,000,000)	$ 119,000,000	$ 38,000,000
Number of parties in joint venture | joint_venture_party		3
Receivables from investees and other airlines
Schedule of Equity Method Investments [Line Items]
Reserve against outstanding receivables from Virgin Atlantic, Virgin Australia, LATAM, Grupo Aeromexico, and others							$ 100,000,000
LATAM
Schedule of Equity Method Investments [Line Items]
Ownership interest (percent)		20.00%		20.00%
Acquisition of strategic investments		$ 1,900,000,000
Per share price in tender offer (USD per share) | $ / shares		$ 16
Total consideration for investment					$ 2,300,000,000
Carrying value of equity investment					1,100,000,000
Impairments and equity method losses				$ 1,100,000,000
Grupo Aeromexico
Schedule of Equity Method Investments [Line Items]
Ownership interest (percent)			51.00%	51.00%
Impairments and equity method losses				$ 770,000,000
Voting interest limit per bylaws (percent)			49.00%
Virgin Atlantic
Schedule of Equity Method Investments [Line Items]
Ownership interest (percent)							49.00%	49.00%
Carrying value of equity investment			$ 0				$ 0	$ 375,000,000
Impairments and equity method losses							$ 510,000,000
Unifi Aviation
Schedule of Equity Method Investments [Line Items]
Ownership interest (percent)							49.00%	49.00%
Carrying value of equity investment							$ 154,000,000	$ 142,000,000
Alliance related
Schedule of Equity Method Investments [Line Items]
Consideration allocated to indefinite-lived intangible asset							1,200,000,000
Indefinite-lived intangibles							1,863,000,000	$ 1,005,000,000
Alliance related | LATAM
Schedule of Equity Method Investments [Line Items]
Consideration allocated to indefinite-lived intangible asset					1,200,000,000
Indefinite-lived intangibles							$ 1,200,000,000
LATAM
Schedule of Equity Method Investments [Line Items]
Planned investment to support establishment of strategic alliance		$ 350,000,000
Restructuring charges	$ 62,000,000			$ 62,000,000
LATAM | Forecast
Schedule of Equity Method Investments [Line Items]
Payments to support establishment of strategic alliance						$ 75,000,000
LATAM | A350
Schedule of Equity Method Investments [Line Items]
Number of aircraft agreed to acquire | aircraft		4
Number of purchase commitments assumed | aircraft		10					10
Number of aircraft in terminated purchase agreement | aircraft	4
LATAM and Grupo Aeromexico
Schedule of Equity Method Investments [Line Items]
Note payable							$ 165,000,000
Receivable							165,000,000
GOL | Loan receivable
Schedule of Equity Method Investments [Line Items]
Loan issued			$ 250,000,000
Loan receivable							93,000,000
Wheels Up
Schedule of Equity Method Investments [Line Items]
Gain on transaction to combine subsidiary with Wheels Up					$ 240,000,000
Virgin Atlantic
Schedule of Equity Method Investments [Line Items]
Receivable							$ 115,000,000
LATAM
Schedule of Equity Method Investments [Line Items]
Ownership interest (percent)							20.00%
Long-term investments							$ 0
Grupo Aeromexico
Schedule of Equity Method Investments [Line Items]
Long-term investments							$ 0
Wheels Up
Schedule of Equity Method Investments [Line Items]
Ownership interest (percent)							24.00%
Related agreements for Virgin Atlantic recapitalization process
Schedule of Equity Method Investments [Line Items]
Note payable							$ 115,000,000
Term loan facility | Financial Guarantee | GOL
Schedule of Equity Method Investments [Line Items]
Guarantee borrowings on third party debt										$ 300,000,000
Guarantee borrowings on third party debt, term (in years)										5 years