Long-term Debt and Short-term Borrowings (Details) shares in Millions, $ in Millions | 1 Months Ended | 3 Months Ended | 6 Months Ended | |
Jun. 30, 2015USD ($)aircraft | Jun. 30, 2015USD ($)aircraftshares | Jun. 30, 2015USD ($)aircraft | Dec. 31, 2014USD ($) |
Debt Instrument [Line Items] | | | | |
Capital Lease Obligations | $ 163 | $ 163 | $ 163 | $ 170 |
Reduction in outstanding debt and capital lease obligations | | | 94 | |
Value of aircraft, engines and other equipment and facilities which were pledged as security under various loan agreements | $ 3,140 | $ 3,140 | $ 3,140 | |
Unencumbered spare engine | aircraft | 34 | 34 | 34 | |
Weighted average interest rate of long-term debt | 4.60% | 4.60% | 4.60% | |
Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year | $ 142 | $ 142 | $ 142 | |
Long-term debt, maturities, repayments of principal in Year Two | 455 | 455 | 455 | |
Long-term debt, maturities, repayments of principal in Year Three | 196 | 196 | 196 | |
Long-term debt, maturities, repayments of principal in Year Four | 207 | 207 | 207 | |
Long-term debt, maturities, repayments of principal in Year Five | 224 | 224 | 224 | |
Long-term debt, maturities, repayments, thereafter | 808 | 808 | 808 | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Carrying Value, Total | 1,869 | 1,869 | 1,869 | 2,063 |
Estimated Fair Value, Total | 2,385 | 2,385 | 2,385 | 2,529 |
Public Debt Floating Rate Class G One Due Two Thousand Sixteen [Member] | | | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Carrying Value, Total | 32 | 32 | 32 | 35 |
Estimated Fair Value, Total | 31 | 31 | 31 | 35 |
Public Debt Floating Rate Class G Two Due Two Thousand Sixteen Member | | | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Carrying Value, Total | 186 | 186 | 186 | 185 |
Estimated Fair Value, Total | 182 | 182 | 182 | 180 |
Public Debt Fixed Rate Special Facility Bonds Due Through Two Thousand Thirty Six [Member] | | | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Carrying Value, Total | 43 | 43 | 43 | 77 |
Estimated Fair Value, Total | 44 | 44 | 44 | 78 |
Public Debt Six Point Seven Five Percentage Convertible Debentures Due In Two Thousand Thirty Nine [Member] | | | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Carrying Value, Total | 86 | 86 | 86 | 86 |
Estimated Fair Value, Total | $ 368 | 368 | $ 368 | 283 |
Public Debt Five Point Five Percentage Convertible Debentures Due In Two Thousand Thirty Eight [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Stock Issued During Period, Value, Conversion of Convertible Securities | | $ 26 | | |
Debt Instrument, Interest Rate, Stated Percentage | 5.50% | 5.50% | 5.50% | |
Stock Issued During Period, Shares, Conversion of Convertible Securities | shares | | 5.8 | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Carrying Value, Total | $ 42 | $ 42 | $ 42 | 68 |
Estimated Fair Value, Total | 196 | 196 | 196 | 241 |
Non Public Debt Fixed Rate Enhanced Equipment Notes Due Through Two Thousand And Twenty Three [Member] | | | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Carrying Value, Total | 207 | 207 | 207 | 217 |
Estimated Fair Value, Total | 212 | 212 | 212 | 224 |
Non Public Debt Floating Rate Equipment Notes Due Through Two Thousand And Twenty Five [Member] | | | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Carrying Value, Total | 252 | 252 | 252 | 276 |
Estimated Fair Value, Total | 256 | 256 | 256 | 277 |
Non Public Debt Fixed Rate Equipment Notes Due Through Two Thousand Twenty Six [Member] | | | | |
Carrying amounts and estimated fair values of long-term debt | | | | |
Carrying Value, Total | 1,021 | 1,021 | 1,021 | 1,119 |
Estimated Fair Value, Total | $ 1,096 | $ 1,096 | $ 1,096 | $ 1,211 |
A-320-200 [Member] | | | | |
Debt Instrument [Line Items] | | | | |
unencumbered aircraft | aircraft | 35 | 35 | 35 | |
A-321 [Member] | | | | |
Debt Instrument [Line Items] | | | | |
unencumbered aircraft | aircraft | 11 | 11 | 11 | |
Secured Debt [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Extinguishment of Debt, Amount | $ 52 | | | |
Secured Debt [Member] | A-320-200 [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Aircraft Pledged as Collateral | aircraft | 7 | 7 | 7 | |
unencumbered aircraft | aircraft | 1 | 1 | 1 | |
Aircraft with Reduced Outstanding Principal | aircraft | 6 | 6 | 6 | |
Municipal Bonds [Member] | | | | |
Debt Instrument [Line Items] | | | | |
Extinguishment of Debt, Amount | $ 32 | | | |