| Financial Instruments - Fair Value of Financial Instruments by Balance Sheet Location (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 3 Months Ended | 3 Months Ended | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mar. 31, 2013 | Mar. 31, 2012 | Mar. 31, 2013
 Prepaid Expenses and Other [Member]
 Fair Value, Inputs, Level 2 [Member]
 Fair Value, Measurements, Recurring [Member] | Mar. 31, 2013
 Other Current Liabilities [Member]
 Fair Value, Inputs, Level 2 [Member]
 Fair Value, Measurements, Recurring [Member] | Mar. 31, 2013
 LNG Inventory Derivatives [Member] | Mar. 31, 2012
 LNG Inventory Derivatives [Member] | Dec. 31, 2012
 LNG Inventory Derivatives [Member]
 Fair Value, Inputs, Level 2 [Member]
 Fair Value, Measurements, Recurring [Member] | Mar. 31, 2013
 LNG Inventory Derivatives [Member]
 Other Current Liabilities [Member]
 Fair Value, Inputs, Level 2 [Member]
 Fair Value, Measurements, Recurring [Member] | Dec. 31, 2012
 LNG Inventory Derivatives [Member]
 Prepaid Expenses And Other [Member]
 Fair Value, Inputs, Level 2 [Member]
 Fair Value, Measurements, Recurring [Member] | Mar. 31, 2013
 Fuel Derivatives [Member] | Mar. 31, 2012
 Fuel Derivatives [Member] | Dec. 31, 2012
 Fuel Derivatives [Member]
 Fair Value, Inputs, Level 2 [Member] | Dec. 31, 2012
 Fuel Derivatives [Member]
 Other Current Liabilities [Member]
 Fair Value, Inputs, Level 2 [Member]
 Fair Value, Measurements, Recurring [Member] | Mar. 31, 2013
 Fuel Derivatives [Member]
 Prepaid Expenses And Other [Member]
 Fair Value, Inputs, Level 2 [Member]
 Fair Value, Measurements, Recurring [Member] | |
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||||||||||||
| Derivative gain (loss) | $ (17,468) | $ (836) | $ (524) | $ 1,859 | $ 515 | $ (836) | ||||||||
| Derivative Assets, Current | 420 | 237 | (420) | 237 | ||||||||||
| Derivative Liabilities, Current | $ (420) | $ (98) | $ (98) | $ 420 | ||||||||||