Debt - Schedule of Long-Term Debt (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Principal Value	$ 5,020,259,000	$ 4,724,920,000
Carrying Value	4,998,979,000	4,697,381,000
Fair Value	4,985,429,000	4,553,427,000
Debt payable within one year, principal value	16,204,000	704,661,000
Debt payable within one year, carrying value	16,204,000	704,390,000
Debt payable within one year, fair value	17,436,000	717,609,000
Total long-term debt, principal value	5,004,055,000	4,020,259,000
Total long-term debt, carrying value	4,982,775,000	3,992,991,000
Total long-term debt, fair value	4,967,993,000	3,835,818,000
Term Loan Facility due May 31, 2021
Debt Instrument [Line Items]
Principal Value	1,000,000,000
Carrying Value	999,353,000
Fair Value	999,353,000
8.125% notes due June 1, 2019
Debt Instrument [Line Items]
Principal Value		700,000,000
Carrying Value		699,729,000
Fair Value		$ 712,663,000
Interest rate		8.125%
Floating rate notes due October 1, 2020
Debt Instrument [Line Items]
Principal Value	500,000,000	$ 500,000,000
Carrying Value	499,238,000	498,222,000
Fair Value	500,290,000	490,730,000
2.50% notes due October 1, 2020
Debt Instrument [Line Items]
Principal Value	500,000,000	500,000,000
Carrying Value	499,228,000	498,198,000
Fair Value	$ 500,950,000	489,690,000
Interest rate	2.50%
8.81% to 9.00% series A due 2020 – 2021
Debt Instrument [Line Items]
Principal Value	$ 35,200,000	35,200,000
Carrying Value	35,200,000	35,200,000
Fair Value	$ 37,380,000	37,920,000
8.81% to 9.00% series A due 2020 – 2021 | Minimum
Debt Instrument [Line Items]
Interest rate	8.81%
8.81% to 9.00% series A due 2020 – 2021 | Maximum
Debt Instrument [Line Items]
Interest rate	9.00%
4.875% notes due November 15, 2021
Debt Instrument [Line Items]
Principal Value	$ 750,000,000	750,000,000
Carrying Value	747,571,000	746,245,000
Fair Value	$ 774,173,000	762,555,000
Interest rate	4.875%
3.00% notes due October 1, 2022
Debt Instrument [Line Items]
Principal Value	$ 750,000,000	750,000,000
Carrying Value	745,579,000	743,972,000
Fair Value	$ 737,025,000	712,980,000
Interest rate	3.00%
7.42% series B due 2023
Debt Instrument [Line Items]
Principal Value	$ 10,000,000	10,000,000
Carrying Value	10,000,000	10,000,000
Fair Value	$ 10,788,000	10,666,000
Interest rate	7.42%
7.75% debentures due July 15, 2026
Debt Instrument [Line Items]
Principal Value	$ 115,000,000	115,000,000
Carrying Value	111,727,000	111,229,000
Fair Value	$ 129,466,000	128,808,000
Interest rate	7.75%
3.90% notes due October 1, 2027
Debt Instrument [Line Items]
Principal Value	$ 1,250,000,000	1,250,000,000
Carrying Value	1,241,024,000	1,239,866,000
Fair Value	$ 1,167,763,000	1,085,663,000
Interest rate	3.90%
EQM Midstream Notes
Debt Instrument [Line Items]
Principal Value	$ 110,059,000	114,720,000
Carrying Value	110,059,000	114,720,000
Fair Value	$ 128,241,000	$ 121,752,000