Changes in Accumulated Other Comprehensive Income (Loss) (Reclassifications) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense, net of interest capitalized	$ (844,238)	$ (408,513)	$ (333,672)
Depreciation and amortization expenses	(1,279,254)	(1,245,942)	(1,033,697)
Other income (Expense)	(137,085)	(24,513)	11,107
Fuel	(371,015)	(697,962)	(710,617)
Reclassification out of accumulated other comprehensive income (loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period	(150,230)	4,426	(12,620)
Reclassification out of accumulated other comprehensive income (loss) | Gain (loss) on cash flow derivative hedges:
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period	(79,119)	5,205	(11,133)
Reclassification out of accumulated other comprehensive income (loss) | Gain (loss) on cash flow derivative hedges: | Interest rate swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense, net of interest capitalized	(25,267)	(4,289)	(10,931)
Reclassification out of accumulated other comprehensive income (loss) | Gain (loss) on cash flow derivative hedges: | Foreign currency forward contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Depreciation and amortization expenses	(14,679)	(14,063)	(12,843)
Other income (Expense)	(7,315)	(5,080)	12,855
Reclassification out of accumulated other comprehensive income (loss) | Gain (loss) on cash flow derivative hedges: | Fuel swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (Expense)	3,549	(1,292)	(1,580)
Fuel	(35,407)	29,929	1,366
Reclassification out of accumulated other comprehensive income (loss) | Actuarial loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Payroll and related	(2,067)	(779)	(1,487)
Reclassification out of accumulated other comprehensive income (loss) | Prior service costs
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Payroll and related	0	0	0
Reclassification out of accumulated other comprehensive income (loss) | Amortization of defined benefit plans:
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period	$ (2,067)	$ (779)	$ (1,487)