Financial Derivative Instruments (Details 2) | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Mar. 31, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Mar. 31, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Mar. 31, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2013 | Dec. 31, 2013 |
Interest rate derivatives | Interest rate derivatives | Foreign currency derivatives | Foreign currency derivatives | Fuel derivative contracts | Fuel derivative contracts | Negative arbitrage derivative | Negative arbitrage derivative | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Derivatives not designated as hedging instruments | Enhanced Equipment Trust Certificates (EETC) |
USD ($) | USD ($) | USD ($) | USD ($) | USD ($) | USD ($) | USD ($) | USD ($) | Interest rate derivatives | Interest rate derivatives | Interest rate derivatives | Interest rate derivatives | Interest rate derivatives | Interest rate derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Foreign currency derivatives | Fuel derivative contracts | Fuel derivative contracts | Negative arbitrage derivative | Negative arbitrage derivative | Negative arbitrage derivative | Negative arbitrage derivative | Negative arbitrage derivative | USD ($) |
| | | | | | | | USD ($) | USD ($) | Prepaid expenses and other | Prepaid expenses and other | Long-term prepayments and other | Long-term prepayments and other | Prepaid expenses and other | Prepaid expenses and other | Long-term prepayments and other | Long-term prepayments and other | Other liabilities and deferred credits | Japanese yen | Japanese yen | Japanese yen | Japanese yen | Japanese yen | Korean Won | Korean Won | Australian dollar | Australian dollar | Australian dollar | Australian dollar | Australian dollar | New Zealand Dollars | New Zealand Dollars | Prepaid expenses and other | Prepaid expenses and other | Other accrued liabilities | Other accrued liabilities | Long-term prepayments and other | Other liabilities and deferred credits | Japanese yen | Japanese yen | Japanese yen | Japanese yen | Australian dollar | Australian dollar | Australian dollar | Australian dollar | Australian dollar | Prepaid expenses and other | Other accrued liabilities | USD ($) | USD ($) | Other accrued liabilities | Other accrued liabilities | Other liabilities and deferred credits | item |
| | | | | | | | | | USD ($) | USD ($) | USD ($) | USD ($) | USD ($) | USD ($) | USD ($) | USD ($) | USD ($) | Prepaid expenses and other | Prepaid expenses and other | Long-term prepayments and other | Long-term prepayments and other | Other liabilities and deferred credits | Prepaid expenses and other | Prepaid expenses and other | Prepaid expenses and other | Prepaid expenses and other | Long-term prepayments and other | Long-term prepayments and other | Other liabilities and deferred credits | Prepaid expenses and other | Prepaid expenses and other | USD ($) | USD ($) | USD ($) | USD ($) | USD ($) | USD ($) | Prepaid expenses and other | Prepaid expenses and other | Other accrued liabilities | Long-term prepayments and other | Prepaid expenses and other | Prepaid expenses and other | Other accrued liabilities | Long-term prepayments and other | Other liabilities and deferred credits | USD ($) | USD ($) | | | USD ($) | USD ($) | USD ($) | |
| | | | | | | | | | | | | | | | | | | JPY (¥) | JPY (¥) | JPY (¥) | JPY (¥) | JPY (¥) | KRW | KRW | AUD | AUD | AUD | AUD | AUD | NZD | NZD | | | | | | | JPY (¥) | JPY (¥) | JPY (¥) | JPY (¥) | AUD | AUD | AUD | AUD | AUD | gal | gal | | | | | | |
Fair Value of Derivatives | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Number of pass-through trusts | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 2 |
Aggregate principal amount issued | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | $444,500,000 |
Amount reduced in connection with the first interest payment made to the trust | ' | ' | ' | ' | ' | ' | 9,200,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Notional Amount | ' | ' | ' | ' | ' | ' | ' | ' | 62,200,000 | 63,800,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | 8,178,790,000 | 10,500,321,000 | 293,400,000 | 1,980,949,000 | 1,694,160,000 | 4,660,979,000 | 10,895,370,000 | 48,823,000 | 62,659,000 | 451,000 | 16,681,000 | 9,146,000 | 2,415,000 | 4,821,000 | ' | ' | ' | ' | ' | ' | 4,169,111,000 | 6,180,000 | 5,290,000 | 647,300,000 | 26,741,000 | 58,000 | 912,000 | 3,840,000 | 648,000 | ' | ' | 444,540,000 | 444,540,000 | ' | ' | ' | ' |
Notional Amount | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 84,714,000 | 94,114,000 | ' | ' | ' | ' | ' | ' |
Gross fair value of assets, current | 91,000 | 196,000 | 3,365,000 | 9,844,000 | ' | 6,093,000 | ' | ' | ' | ' | 91,000 | 196,000 | ' | ' | 2,769,000 | 9,946,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 1,769,000 | 577,000 | 153,000 | 298,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 13,587,000 | 3,753,000 | ' | ' | ' | ' | ' | ' |
Gross fair value of assets, noncurrent | 684,000 | 925,000 | 358,000 | 1,673,000 | ' | ' | ' | ' | ' | ' | ' | ' | 684,000 | 925,000 | ' | ' | 49,000 | 1,673,000 | 191,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 324,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
Gross fair value of liabilities, current | ' | ' | -124,000 | -211,000 | -3,537,000 | ' | -3,668,000 | -12,250,000 | ' | ' | ' | ' | ' | ' | -996,000 | -450,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -177,000 | -229,000 | -277,000 | -509,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -7,494,000 | -7,290,000 | ' | ' | -3,668,000 | -12,250,000 | ' | ' |
Gross fair value of liabilities, noncurrent | ' | ' | -173,000 | ' | ' | ' | ' | -615,000 | ' | ' | ' | ' | ' | ' | ' | ' | -15,000 | ' | -346,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -18,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | -615,000 | ' |
Net derivative position | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | $91,000 | $196,000 | $684,000 | $925,000 | $1,773,000 | $9,496,000 | $34,000 | $1,673,000 | ($155,000) | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | $1,592,000 | $348,000 | ($124,000) | ($211,000) | $324,000 | ($18,000) | ' | ' | ' | ' | ' | ' | ' | ' | ' | $6,093,000 | ($3,537,000) | ' | ' | ($3,668,000) | ($12,250,000) | ($615,000) | ' |