Leases and Aircraft Maintenance Deposits - Future Minimum Lease Payments Under Finance and Operating Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Finance Leases
2020	$ 44,980
2021	606
2022	578
2023	202
2024	0
2025 and thereafter	0
Total minimum lease payments	46,366
Less amount representing interest	285
Present value of minimum lease payments	46,081
Less current portion	44,796
Long-term portion	1,285
Operating Leases
Less current portion	120,662	$ 0
Long-term portion	1,218,014	$ 0
Total Operating and Finance Lease Obligations
2020	241,978
2021	196,677
2022	197,415
2023	184,439
2024	161,714
2025 and thereafter	1,060,417
Total minimum lease payments	2,042,640
Less amount representing interest	657,883
Present value of minimum lease payments	1,384,757
Less current portion	165,458
Long-term portion	1,219,299
Aircraft and Spare Engine Leases
Operating Leases
2020	192,937
2021	192,539
2022	193,616
2023	181,667
2024	159,668
2025 and thereafter	921,721
Total minimum lease payments	1,842,148
Less amount representing interest	526,760
Present value of minimum lease payments	1,315,388
Less current portion	117,861
Long-term portion	1,197,527
Property Facility Leases
Operating Leases
2020	3,544
2021	3,532
2022	3,221
2023	2,570
2024	2,046
2025 and thereafter	138,696
Total minimum lease payments	153,609
Less amount representing interest	130,825
Present value of minimum lease payments	22,784
Less current portion	2,297
Long-term portion	20,487
Other
Operating Leases
2020	517
2021	0
2022	0
2023	0
2024	0
2025 and thereafter	0
Total minimum lease payments	517
Less amount representing interest	13
Present value of minimum lease payments	504
Less current portion	504
Long-term portion	$ 0