Segment Information Reconciliation of Earnings Before Income Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss)	$ 1,098,668	$ 118,581	$ (585,348)
Gain on Certain Asset Sales	14,571	(3,825)	(4,783)
Gain on Certain Asset Sales	157,015	188,063	14,270
Loss on Debt Extinguishment	(54,118)	(2,129)	0
Impairment of Other Intangible Assets	(18,650)	0	0
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss)	378,427	(63,527)	(594,394)
Corporate, Non-Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss)	720,241	182,108	9,046
Gain on Certain Asset Sales	14,571	(3,826)	(5,224)
Gain on Certain Asset Sales	154,775	188,063	14,270
Gain on Previously Held Equity Interest	623,663	0	0
Loss on Debt Extinguishment	(54,118)	(2,129)	0
Impairment of Other Intangible Assets	(18,650)	0	0
Exploration and Production Equipment | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss)	244,616	(63,527)	(594,394)
Midstream | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss)	$ 133,811	$ 0	$ 0