XML 63 R51.htm IDEA: XBRL DOCUMENT v3.10.0.1
Commitments and Contingencies - Aircraft Purchase Commitments By Period (Details) - Future aircraft purchase commitments
$ in Millions
Sep. 30, 2018
USD ($)
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity  
Three months ending December 31, 2018 $ 640
2019 3,330
2020 3,420
2021 3,920
2022 2,440
Thereafter 1,770
Total $ 15,520