Long-term Debt, Short-term Borrowings and Finance Lease Obligations (Details) - USD ($) $ in Millions | 1 Months Ended | 6 Months Ended | | |
May 08, 2020 | Jun. 30, 2020 | Apr. 23, 2020 | Dec. 31, 2019 |
Debt Instrument [Line Items] | | | | |
Long-term Debt | | $ 3,711 | | $ 2,245 |
Reduction in outstanding debt and capital lease obligations | | 180 | | |
Value of aircraft, engines and other equipment and facilities which were pledged as security under various loan agreements | | 6,300 | | |
Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year | | 177 | | |
Long-term debt, maturities, repayments of principal in Year Two | | 1,400 | | |
Long-term debt, maturities, repayments of principal in Year Three | | 348 | | |
Long-term debt, maturities, repayments of principal in Year Four | | 878 | | |
Long-term debt, maturities, repayments of principal in Year Five | | 897 | | |
Long-term debt, maturities, repayments of principal after Year Five | | 1,100 | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Estimated Fair Value, Total | | 3,532 | | 2,367 |
Public Debt Fixed Rate Special Facility Bonds Due Through Two Thousand Thirty Six [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Long-term Debt | | 42 | | 42 |
Carrying amounts and estimated fair values of long-term debt | | | | |
Estimated Fair Value, Total | | 43 | | 46 |
Fixed rate enhanced equipment notes, due through 2032 [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Long-term Debt | | 574 | | 581 |
Carrying amounts and estimated fair values of long-term debt | | | | |
Estimated Fair Value, Total | | 419 | | 586 |
Fixed rate enhanced equipment notes, due through 2028 [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Long-term Debt | | 179 | | 181 |
Carrying amounts and estimated fair values of long-term debt | | | | |
Estimated Fair Value, Total | | 147 | | 186 |
Non Public Debt Fixed Rate Enhanced Equipment Notes Due Through Two Thousand And Twenty Three [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Long-term Debt | | 125 | | 133 |
Carrying amounts and estimated fair values of long-term debt | | | | |
Estimated Fair Value, Total | | 125 | | 141 |
Non Public Debt Floating Rate Equipment Notes Due Through Two Thousand And Twenty Eight [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Long-term Debt | | 176 | | 201 |
Carrying amounts and estimated fair values of long-term debt | | | | |
Estimated Fair Value, Total | | 162 | | 207 |
Non Public Debt Fixed Rate Equipment Notes Due Through Two Thousand Twenty Eight [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Long-term Debt | | 984 | | 1,107 |
Carrying amounts and estimated fair values of long-term debt | | | | |
Estimated Fair Value, Total | | 1,001 | | 1,201 |
Non Public Debt Floating Rate Term Loan Credit Facility Due Through 2024 [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Long-term Debt | | 717 | | 0 |
Carrying amounts and estimated fair values of long-term debt | | | | |
Estimated Fair Value, Total | | 764 | | 0 |
Non Public Debt Unsecured CARES Act Payroll Support Program loan due through 2025 [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Long-term Debt | | 251 | | 0 |
Carrying amounts and estimated fair values of long-term debt | | | | |
Estimated Fair Value, Total | | 217 | | 0 |
Non Public Debt Sale Leaseback Transactions due through 2024 [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Long-term Debt | | 117 | | 0 |
Carrying amounts and estimated fair values of long-term debt | | | | |
Estimated Fair Value, Total | | 134 | | 0 |
Non Public Debt Citibank Line of Credit due through 2023 [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Long-term Debt | | 546 | | 0 |
Carrying amounts and estimated fair values of long-term debt | | | | |
Estimated Fair Value, Total | | 520 | | 0 |
Barclays [Member] | Non Public Debt Floating Rate Term Loan Credit Facility Due Through 2024 [Member] | Long-term Debt [Member] | | | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Debt Instrument, Face Amount | | 750 | | |
US Department of Treasury [Member] | Unsecured Debt [Member] | | | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Debt Instrument, Face Amount | | 251 | | |
Debt Instrument, Interest Rate, Stated Percentage | | | 1.00% | |
Long-term Debt, Term | | | 10 years | |
Citibank [Member] | Non Public Debt Citibank Line of Credit due through 2023 [Member] | Line of Credit [Member] | | | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Line of Credit, Current | | 550 | | |
Morgan Stanley [Member] | | | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Line of Credit, Current | | $ 0 | | $ 0 |
Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] | US Department of Treasury [Member] | Unsecured Debt [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Debt Instrument, Basis Spread on Variable Rate | 2.00% | | | |
London Interbank Offered Rate (LIBOR) [Member] | Barclays [Member] | Non Public Debt Floating Rate Term Loan Credit Facility Due Through 2024 [Member] | Long-term Debt [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Debt Instrument, Description of Variable Rate Basis | | LIBOR (subject to a 1.00% floor), or at our election another rate, in each case, plus a specified margin | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Debt Instrument, Interest Rate, Stated Percentage | | 6.25% | | |
London Interbank Offered Rate (LIBOR) [Member] | Citibank [Member] | Non Public Debt Citibank Line of Credit due through 2023 [Member] | Line of Credit [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Debt Instrument, Description of Variable Rate Basis | | LIBOR, plus a margin | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Line of Credit Facility, Interest Rate During Period | | 2.99% | | |
Short-term Debt [Member] | Morgan Stanley [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Short-term Debt, Fair Value | | $ 997 | | |
Debt Issuance Costs, Net | | 13 | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Debt Instrument, Face Amount | | $ 1,000 | | |
Short-term Debt [Member] | London Interbank Offered Rate (LIBOR) [Member] | Morgan Stanley [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Debt Instrument, Description of Variable Rate Basis | | LIBOR (but not less than 1% per annum), plus a margin | | |
Short-term Debt, Weighted Average Interest Rate, at Point in Time | | 2.75% | | |
Line of Credit [Member] | Morgan Stanley [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Line of Credit Facility, Maximum Borrowing Capacity | | $ 200 | | |
Line of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member] | Morgan Stanley [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Debt Instrument, Description of Variable Rate Basis | | LIBOR, plus a margin | | |