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Financial Derivative Instruments - Fair Values of Fuel Derivatives Amounts Posted as Collateral (Details) $ in Millions | Dec. 31, 2017 USD ($)
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Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Maximum Sum Of Derivatives Of Counterparty To Be Included In Other | $ 5 |
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Cash Collateral Percent Of Fair Value Fuel Derivatives Contracts | 100.00% |
Letter of Credit Percent of Collateral | 100.00% |
Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Fair value of fuel derivatives - asset | $ 248 |
Collateral Already Posted, Aggregate Fair Value | 15 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty A | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Fair value of fuel derivatives - asset | 89 |
Collateral Already Posted, Aggregate Fair Value | 15 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty A | Minimum | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (200) | [1]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (50) |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (600) |
Fair value of fuel derivative level at which cash is received from CP | 50 | [2]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (200) | [3]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | 0 |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (600) |
Fair value of fuel derivative level at which cash is received from CP |  | [4]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (200) |
Counterparty A | Maximum | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (600) | [1]
Option to substitute LC for cash Threshold 1 |  |
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (200) |
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (600) | [3]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (200) |
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (600) |
Counterparty B | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Fair value of fuel derivatives - asset | 44 |
Collateral Already Posted, Aggregate Fair Value | 0 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty B | Minimum | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (100) | [5]
Option to substitute LC for cash Threshold 1 | (500) | [5]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (50) |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (500) |
Fair value of fuel derivative level at which cash is received from CP | 150 | [2]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (100) | [5]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | 0 |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (500) |
Fair value of fuel derivative level at which cash is received from CP |  | [4]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (100) |
Counterparty B | Maximum | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (500) | [5]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (100) |
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (500) | [5]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (100) |
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (500) |
Counterparty C | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Fair value of fuel derivatives - asset | 54 |
Collateral Already Posted, Aggregate Fair Value | 0 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty C | Minimum | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (150) | [5]
Option to substitute LC for cash Threshold 1 | (75) | [5]
Option to substitute LC for cash Threshold 2 | (550) | [5]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (75) | [2]
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (550) | [2]
Fair value of fuel derivative level at which cash is received from CP | 250 | [2]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (150) | [5]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | 0 |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (550) |
Fair value of fuel derivative level at which cash is received from CP |  | [4]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (150) |
Counterparty C | Maximum | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (550) | [5]
Option to substitute LC for cash Threshold 1 | (150) | [5]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (150) | [2]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (550) | [5]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (150) |
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (550) |
Counterparty D | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Fair value of fuel derivatives - asset | 35 |
Collateral Already Posted, Aggregate Fair Value | 0 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty D | Minimum | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (150) | [5]
Option to substitute LC for cash Threshold 1 | (125) | [6]
Option to substitute LC for cash Threshold 2 | (550) | [6]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (125) | [2]
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (550) | [2]
Fair value of fuel derivative level at which cash is received from CP | 75 | [2]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (150) | [5]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | 0 |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 2 | (550) |
Fair value of fuel derivative level at which cash is received from CP |  | [4]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (150) |
Counterparty D | Maximum | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for aircraft | (550) | [5]
Option to substitute LC for cash Threshold 1 | (150) | [6]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (150) | [2]
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (550) | [5]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (150) |
Fair value of fuel derivative levels at which aircraft or cash collateral is pledged to CP | (550) |
Counterparty E | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Fair value of fuel derivatives - asset | 15 |
Collateral Already Posted, Aggregate Fair Value | 0 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty E | Minimum | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Option to substitute LC for cash Threshold 1 |  | [6]
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (125) |
Fair value of fuel derivative level at which cash is received from CP | 100 | [2]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 |  | [4]
Fair value of fuel derivative level at which cash is received from CP |  | [4]
Counterparty F | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Fair value of fuel derivatives - asset | 6 |
Collateral Already Posted, Aggregate Fair Value | 0 |
Aircraft collateral pledged to CP | 0 |
Letters of credit (LC) | 0 |
Counterparty F | Minimum | Fuel derivatives |  |
If credit rating is investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 | (65) | [2]
Fair value of fuel derivative level at which cash is received from CP | 30 | [2]
If credit rating is non-investment grade, fair value of fuel derivative level at which: |  |
Fair value of fuel derivative levels at which cash is provided to CP Threshold 1 |  | [4]
Fair value of fuel derivative level at which cash is received from CP |  | [4]
Counterparty Other | Fuel derivatives |  |
Schedule Of Fair Values Of Fuel Derivatives Amounts Posted As Collateral And Collateral Posting Thresholds [Line Items] |  |
Fair value of fuel derivatives - asset | 5 | [7]
Collateral Already Posted, Aggregate Fair Value | 0 | [7]
Aircraft collateral pledged to CP | 0 | [7]
Letters of credit (LC) | $ 0 | [7]
[1] | The Company has the option of providing letters of credit in addition to aircraft collateral if the appraised value of the aircraft does not meet the collateral requirement.
[2] | Thresholds may vary based on changes in credit ratings within investment grade.
[3] | The Company has the option of providing cash or pledging aircraft as collateral.
[4] | Cash collateral is provided at 100 percent of fair value of fuel derivative contracts.
[5] | The Company has the option of providing cash, letters of credit, or pledging aircraft as collateral.
[6] | The Company has the option to substitute letters of credit for 100 percent of cash collateral requirement.
[7] | Individual counterparties with fair value of fuel derivatives <$5 million.

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- Definition The aggregate fair value of assets (aircraft) pledged, at the end of the reporting period, as collateral for outstanding derivative instruments with credit-risk-related contingent features. + References No definition available. + Details
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