Leases (Future Minimum Lease Payments for Operating Leases) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	[1]
Leases
July 1, 2019, to December 31, 2019	$ 159,243
2020	309,828
2021	281,443
2022	256,477
2023	225,877
Thereafter	1,202,770
Total operating lease payments	2,435,638
Less: present value discount	499,885
Total operating lease liabilities	1,935,753
Less: current portion of operating lease liabilities	304,034	$ 0
Operating lease liabilities, less current portion	1,631,719	$ 0
Related parties [Member]
Leases
July 1, 2019, to December 31, 2019	2,375
2020	3,988
2021	3,521
2022	2,763
2023	2,540
Thereafter	3,544
Total operating lease payments	18,731
Less: present value discount	2,054
Total operating lease liabilities	16,677
Less: current portion of operating lease liabilities	4,418
Operating lease liabilities, less current portion	12,259
Non-related parties [Member]
Leases
July 1, 2019, to December 31, 2019	156,868
2020	305,840
2021	277,922
2022	253,714
2023	223,337
Thereafter	1,199,226
Total operating lease payments	2,416,907
Less: present value discount	497,831
Total operating lease liabilities	1,919,076
Less: current portion of operating lease liabilities	299,616
Operating lease liabilities, less current portion	$ 1,619,460

[1] The balance sheet at December 31, 2018, has been derived from the audited consolidated financial statements at that date but does not include all of the information and footnotes required by United States generally accepted accounting principles for complete financial statements.