XML 68 R50.htm IDEA: XBRL DOCUMENT v3.10.0.1
Debt - Contractual Principal Payments (Details) - UAL And United
$ in Millions
Sep. 30, 2018
USD ($)
Debt Instrument [Line Items]  
Last three months of 2018 $ 208
2019 1,205
2020 1,242
2021 1,230
2022 1,565
After 2022 7,838
Long-term debt $ 13,288