Discontinued Operations - Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations after income taxes	$ 0	$ 190,795	$ 0	$ 537,673
Net income from discontinued operations	$ 0	87,654	$ 0	174,977
Midstream Business | Discontinued Operations, Disposed of by Means Other than Sale, Spinoff
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating revenues		108,824		334,394
Transportation and processing		(234,340)		(688,876)
Operation and maintenance		29,909		82,458
Selling, general and administrative		13,584		41,238
Depreciation		47,295		138,458
Transaction costs		22,714		69,246
Amortization of intangible assets		10,387		31,160
Other income		17,432		39,029
Interest expense		36,862		68,848
Income from discontinued operations before income taxes		199,845		630,891
Income tax expense		9,050		93,218
Income from discontinued operations after income taxes		190,795		537,673
Less: Net income from discontinued operations attributable to noncontrolling interests		103,141		362,696
Net income from discontinued operations		$ 87,654		$ 174,977