Commitments and contingencies - Narrative (Details) $ in Millions		3 Months Ended
	Sep. 28, 2021 USD ($)	Sep. 30, 2022 USD ($) aircraft	Dec. 31, 2022 aircraft
Other Commitments [Line Items]
Aircrafts to be purchased | aircraft		632
MAX aircrafts to be delivered this year | aircraft		114
Cash Capital Commitments, Boeing Orders
Other Commitments [Line Items]
Remainder of 2022		$ 1,900
2023		2,300
2024		932
2025		853
2026		999
2027		1,100
Thereafter		$ 6,400
-8 Firm Orders
Other Commitments [Line Items]
Aircrafts to be purchased | aircraft		278
Estimated MAX aircrafts to be delivered this year | aircraft		66
-8 Firm Orders | Forecast
Other Commitments [Line Items]
Estimated MAX aircrafts to be delivered this year | aircraft			31
-7 Firm Orders
Other Commitments [Line Items]
Exercised, 2022 | aircraft		5
Exercised, 2023 | aircraft		4
Aircrafts to be purchased | aircraft		196
Estimated MAX aircrafts to be delivered this year | aircraft		0
Payment Guarantee, Dallas Love Field Series 2010 Bonds
Other Commitments [Line Items]
Principal amount of guarantee		$ 79
Net present value of future principal and interest payments		$ 88
Love Field Airport Modernization Corporation | Series 2010 Bonds
Other Commitments [Line Items]
Cash paid for debt and interest	$ 310