Fair Value Measurements and Derivative Instruments (Details 10) (Cash flow hedge, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Effect of derivative instruments involved in cash flow hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	$ 58,138	$ 70,480
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	109,385	146,586
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness testing)	(1,389)	6,050
Cross currency swaps | Other income (expense)
Effect of derivative instruments involved in cash flow hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	851	(6,013)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	2,505	(15,011)
Cross currency swaps | Interest Expense
Effect of derivative instruments involved in cash flow hedging on the consolidated financial statements
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(2,209)
Interest rate swaps | Other income (expense)
Effect of derivative instruments involved in cash flow hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	(44,971)	(10,131)
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness testing)	(348)	(21)
Foreign currency forward contracts | Other income (expense)
Effect of derivative instruments involved in cash flow hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)		(12,375)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(953)	(285)
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness testing)		(1,015)
Foreign currency forward contracts | Depreciation and amortization expenses
Effect of derivative instruments involved in cash flow hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	11,928	(22,263)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(953)	(734)
Foreign currency collar options | Depreciation and amortization expenses
Effect of derivative instruments involved in cash flow hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	3,316
Fuel contracts | Swaps | Other income (expense)
Effect of derivative instruments involved in cash flow hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness testing)	(1,041)	7,086
Fuel contracts | Swaps | Fuel cost
Effect of derivative instruments involved in cash flow hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion)	87,014	121,262
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ 110,995	$ 162,616