Impairments of Property, Equipment, Goodwill and Intangible Assets (Narrative) (Details)	9 Months Ended
	Sep. 30, 2020 USD ($) segment property	Sep. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Impairment of property and equipment	$ 417,384,000
Property and equipment, net	5,193,378,000			$ 5,516,347,000
Intangible assets, net	1,127,279,000			$ 1,163,063,000
Impairment of intangible assets	0
Adjustments to contingent consideration	$ 16,852,000	$ 1,466,000
Number of geographic operating segments | segment	5
E&P [Member]
Decline in revenue from prior year period	$ 75,158,000
Exploration and Production [Member]
Impairment of property and equipment	417,384,000
Adjustments to contingent consideration	$ (4,145,000)
Contingent consideration			$ 0
Exploration and Production [Member] | Valuation Technique, Discounted Cash Flow [Member]
Number of landfills impaired | property	4
Impairment charge if estimated annual cash flows was changed by ten percent	$ 3,000,000
Exploration and Production [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rate [Member]
Derivative Asset (Liability) Net, Measurement Input			0.12
Exploration and Production [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Expected Term [Member]
Derivative Asset (Liability) Net, Measurement Input			40
Exploration and Production [Member] | Four Landfill [Member]
Intangible assets, net			$ 0
Exploration and Production [Member] | Certain Basins [Member]
Percentage decline in revenue from prior year period	72.00%