Leases Finance and Operating Lease Maturities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Finance Leases
remainder of 2019	$ 94,751
2020	780
2021	606
2022	578
2023	202
2024 and thereafter	0
Total minimum lease payments	96,917
Less amount representing interest	535
Present value of minimum lease payments	96,382
Less current portion	94,834
Long-term portion	1,548
Operating Leases
Less current portion	114,877	$ 0
Long-term portion	915,288	$ 0
Total Operating and Finance Lease Obligations
remainder of 2019	184,973
2020	176,123
2021	173,683
2022	174,609
2023	156,333
2024 and thereafter	597,642
Total minimum lease payments	1,463,363
Less amount representing interest	336,816
Present value of minimum lease payments	1,126,547
Less current portion	209,711
Long-term portion	916,836
Aircraft and Spare Engine Leases
Operating Leases
remainder of 2019	88,536
2020	172,409
2021	171,168
2022	172,951
2023	155,076
2024 and thereafter	592,704
Total minimum lease payments	1,352,844
Less amount representing interest	332,667
Present value of minimum lease payments	1,020,177
Less current portion	112,189
Long-term portion	907,988
Property Facility Leases
Operating Leases
remainder of 2019	1,396
2020	2,417
2021	1,909
2022	1,080
2023	1,055
2024 and thereafter	4,938
Total minimum lease payments	12,795
Less amount representing interest	3,583
Present value of minimum lease payments	9,212
Less current portion	2,137
Long-term portion	7,075
Other
Operating Leases
remainder of 2019	290
2020	517
2021	0
2022	0
2023	0
2024 and thereafter	0
Total minimum lease payments	807
Less amount representing interest	31
Present value of minimum lease payments	776
Less current portion	551
Long-term portion	$ 225