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Fair Value Measurements - Measured on Recurring Basis (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2016 | Dec. 31, 2015
Fuel derivatives: |  |  |  |  |
Derivative Asset, Fair Value, Gross Asset | [1] | $ 1,437 |  | $ 1,937 |
Total gains or (losses) (realized or unrealized) |  |  |  |  |
Included in earnings |  | 34 |  |  |
Included in other comprehensive income |  | (53) |  |  |
Purchases |  | 71 |  |  |
Accounts payable trade |  | 191 |  | 178 |
Sales |  | (29) |  |  |
Settlements |  | (239) |  |  |
The amount of total losses for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at March 31, 2016 |  | 21 |  |  |
Fuel derivatives: |  |  |  |  |
Derivative Liability, Fair Value, Gross Liability | [1] | (2,875) |  | (3,465) |
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount |  | 0 |  | 0 |
Fair Value, Liabilities, Level 1 to Level 2 Transfers, Amount |  | 0 |  | 0 |
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount |  | 0 |  | 0 |
Fair Value, Liabilities, Level 2 to Level 1 Transfers, Amount |  | 0 |  | 0 |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net |  | 0 |  | 0 |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Transfers, Net |  | 0 |  | 0 |
Fair Value, Measurements, Recurring | Period end date |  |  |  |  |
Assets |  |  |  |  |
Treasury bills |  | 968 |  | 1,248 |
Interest rate derivatives (see Note 3) |  | 16 |  | 2 |
Fuel derivatives: |  |  |  |  |
Other available for sale securities |  | 89 |  | 93 |
Total gains or (losses) (realized or unrealized) |  |  |  |  |
Total assets |  | 5,108 |  | 5,081 |
Liabilities |  |  |  |  |
Interest rate derivatives (see Note 3) |  | (46) |  | (49) |
Total Liabilities |  | (2,875) |  | (3,465) |
Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) |  |  |  |  |
Assets |  |  |  |  |
Treasury bills |  | 968 |  | 1,248 |
Interest rate derivatives (see Note 3) |  | 0 |  | 0 |
Fuel derivatives: |  |  |  |  |
Other available for sale securities |  | 63 |  | 66 |
Total gains or (losses) (realized or unrealized) |  |  |  |  |
Total assets |  | 3,214 |  | 2,651 |
Liabilities |  |  |  |  |
Interest rate derivatives (see Note 3) |  | 0 |  | 0 |
Total Liabilities |  | 0 |  | 0 |
Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) |  |  |  |  |
Assets |  |  |  |  |
Treasury bills |  | 0 |  | 0 |
Interest rate derivatives (see Note 3) |  | 16 |  | 2 |
Fuel derivatives: |  |  |  |  |
Other available for sale securities |  | 0 |  | 0 |
Total gains or (losses) (realized or unrealized) |  |  |  |  |
Total assets |  | 1,119 |  | 1,437 |
Liabilities |  |  |  |  |
Interest rate derivatives (see Note 3) |  | (46) |  | (49) |
Total Liabilities |  | (645) |  | (823) |
Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) |  |  |  |  |
Assets |  |  |  |  |
Treasury bills |  | 0 |  | 0 |
Interest rate derivatives (see Note 3) |  | 0 |  | 0 |
Fuel derivatives: |  |  |  |  |
Other available for sale securities |  | 26 |  | 27 |
Total gains or (losses) (realized or unrealized) |  |  |  |  |
Total assets |  | 775 |  | 993 |
Liabilities |  |  |  |  |
Interest rate derivatives (see Note 3) |  | 0 |  | 0 |
Total Liabilities |  | (2,230) |  | (2,642) |
Cash Equivalents | Fair Value, Measurements, Recurring | Period end date |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 2,183 | [2] | 1,337 | [3]
Cash Equivalents | Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 2,183 | [2] | 1,337 | [3]
Cash Equivalents | Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 0 | [2] | 0 | [3]
Cash Equivalents | Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 0 | [2] | 0 | [3]
Commercial paper | Fair Value, Measurements, Recurring | Period end date |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 125 |  | 200 |
Commercial paper | Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 0 |  | 0 |
Commercial paper | Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 125 |  | 200 |
Commercial paper | Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 0 |  | 0 |
Certificates of deposit | Fair Value, Measurements, Recurring | Period end date |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 10 |  | 13 |
Certificates of deposit | Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 0 |  | 0 |
Certificates of deposit | Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 10 |  | 13 |
Certificates of deposit | Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 0 |  | 0 |
Eurodollar time deposits | Fair Value, Measurements, Recurring | Period end date |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 70 |  | 33 |
Eurodollar time deposits | Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 0 |  | 0 |
Eurodollar time deposits | Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 70 |  | 33 |
Eurodollar time deposits | Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) |  |  |  |  |
Assets |  |  |  |  |
Cash equivalents |  | 0 |  | 0 |
Certificates of deposit | Fair Value, Measurements, Recurring | Period end date |  |  |  |  |
Assets |  |  |  |  |
Investments |  | 226 |  | 220 |
Certificates of deposit | Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) |  |  |  |  |
Assets |  |  |  |  |
Investments |  | 0 |  | 0 |
Certificates of deposit | Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) |  |  |  |  |
Assets |  |  |  |  |
Investments |  | 226 |  | 220 |
Certificates of deposit | Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) |  |  |  |  |
Assets |  |  |  |  |
Investments |  | 0 |  | 0 |
Swap | Fair Value, Measurements, Recurring | Period end date |  |  |  |  |
Fuel derivatives: |  |  |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 28 | [4] | 38 | [5]
Derivative Liability, Fair Value, Gross Asset |  | 644 | [6] | 931 | [7]
Fuel derivatives: |  |  |  |  |
Derivative Liability, Fair Value, Gross Liability |  | (599) | [6] | (774) | [7]
Swap | Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) |  |  |  |  |
Fuel derivatives: |  |  |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 0 | [4] | 0 | [5]
Derivative Liability, Fair Value, Gross Asset |  | 0 | [6] | 0 | [7]
Fuel derivatives: |  |  |  |  |
Derivative Liability, Fair Value, Gross Liability |  | 0 | [6] | 0 | [7]
Swap | Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) |  |  |  |  |
Fuel derivatives: |  |  |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 28 | [4] | 38 | [5]
Derivative Liability, Fair Value, Gross Asset |  | 644 | [6] | 931 | [7]
Fuel derivatives: |  |  |  |  |
Derivative Liability, Fair Value, Gross Liability |  | (599) | [6] | (774) | [7]
Swap | Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) |  |  |  |  |
Fuel derivatives: |  |  |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 0 | [4] | 0 | [5]
Derivative Liability, Fair Value, Gross Asset |  | 0 | [6] | 0 | [7]
Fuel derivatives: |  |  |  |  |
Derivative Liability, Fair Value, Gross Liability |  | 0 | [6] | 0 | [7]
Options Held | Fair Value, Measurements, Recurring | Period end date |  |  |  |  |
Fuel derivatives: |  |  |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 47 | [4] | 10 | [5]
Derivative Liability, Fair Value, Gross Asset |  | 702 | [6] | 956 | [7]
Fuel derivatives: |  |  |  |  |
Derivative Asset, Fair Value, Gross Liability |  | (45) | [4] | (26) | [5]
Derivative Liability, Fair Value, Gross Liability |  | (2,185) | [6] | (2,616) | [7]
Options Held | Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) |  |  |  |  |
Fuel derivatives: |  |  |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 0 | [4] | 0 | [5]
Derivative Liability, Fair Value, Gross Asset |  | 0 | [6] | 0 | [7]
Fuel derivatives: |  |  |  |  |
Derivative Asset, Fair Value, Gross Liability |  | 0 | [4] | 0 | [5]
Derivative Liability, Fair Value, Gross Liability |  | 0 | [6] | 0 | [7]
Options Held | Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) |  |  |  |  |
Fuel derivatives: |  |  |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 0 | [4] | 0 | [5]
Derivative Liability, Fair Value, Gross Asset |  | 0 | [6] | 0 | [7]
Fuel derivatives: |  |  |  |  |
Derivative Asset, Fair Value, Gross Liability |  | 0 | [4] | 0 | [5]
Derivative Liability, Fair Value, Gross Liability |  | 0 | [6] | 0 | [7]
Options Held | Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) |  |  |  |  |
Fuel derivatives: |  |  |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 47 | [4] | 10 | [5]
Derivative Liability, Fair Value, Gross Asset |  | 702 | [6] | 956 | [7]
Fuel derivatives: |  |  |  |  |
Derivative Asset, Fair Value, Gross Liability |  | (45) | [4] | (26) | [5]
Derivative Liability, Fair Value, Gross Liability |  | $ (2,185) | [6] | $ (2,616) | [7]
[1] | Represents the position of each trade before consideration of offsetting positions with each counterparty and does not include the impact of cash collateral deposits provided to or received from counterparties. See discussion of credit risk and collateral following in this Note.
[2] | Cash equivalents are primarily composed of money market investments.
[3] | Cash equivalents are primarily composed of money market investments.
[4] | In the unaudited Condensed Consolidated Balance Sheet amounts are presented as a net asset. See Note 3.
[5] | In the unaudited Consolidated Balance Sheet amounts are presented as a net asset. See Note 3.
[6] | In the unaudited Condensed Consolidated Balance Sheet amounts are presented as a net liability. See Note 3.
[7] | In the unaudited Consolidated Balance Sheet amounts are presented as a net liability. See Note 3.

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- Definition Carrying value as of the balance sheet date of obligations incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Current Liabilities -URI http://asc.fasb.org/extlink&oid=6509677 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6935-107765 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(a)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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