Long-Term Debt and Finance Lease Obligations - Long term debt (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Long-term debt
Carrying Amount	$ 9,525,996	$ 10,625,996
Fair Value	9,740,901	11,096,954
Unamortized deferred financing costs and debt discounts, net	(13,581)	(16,250)
Finance lease obligations	188,809	212,617
Total long-term debt and finance lease obligations (including current portion)	$ 9,701,224	10,822,363
5 1/8% Senior Notes due 2020
Long-term debt
Carrying Amount		1,100,000
Fair Value		$ 1,110,208
Interest rate (as a percent)	5.125%	5.125%
6 3/4% Senior Notes due 2021
Long-term debt
Carrying Amount	$ 2,000,000	$ 2,000,000
Fair Value	$ 2,045,100	$ 2,109,420
Interest rate (as a percent)	6.75%	6.75%
5 7/8% Senior Notes due 2022
Long-term debt
Carrying Amount	$ 2,000,000	$ 2,000,000
Fair Value	$ 2,043,040	$ 2,129,580
Interest rate (as a percent)	5.875%	5.875%
5% Senior Notes due 2023
Long-term debt
Carrying Amount	$ 1,500,000	$ 1,500,000
Fair Value	$ 1,495,545	$ 1,543,770
Interest rate (as a percent)	5.00%	5.00%
5 7/8% Senior Notes due 2024
Long-term debt
Carrying Amount	$ 2,000,000	$ 2,000,000
Fair Value	$ 2,000,340	$ 2,049,080
Interest rate (as a percent)	5.875%	5.875%
7 3/4% Senior Notes due 2026
Long-term debt
Carrying Amount	$ 2,000,000	$ 2,000,000
Fair Value	$ 2,130,880	$ 2,128,900
Interest rate (as a percent)	7.75%	7.75%
Other notes payable
Long-term debt
Carrying Amount	$ 25,996	$ 25,996
Fair Value	$ 25,996	$ 25,996