Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue
Revenues from contracts with customers	$ 896,612	$ 1,019,555	$ 2,980,757	$ 2,865,104
Income from derivatives and other sources	222,269	56,977	475,195	228,874
Total revenue	1,118,881	1,076,532	3,455,952	3,093,978
Natural gas sales
Disaggregation of Revenue
Revenues from contracts with customers	524,448	527,122	1,735,086	1,498,324
Oil sales
Disaggregation of Revenue
Revenues from contracts with customers	40,561	59,722	137,675	128,869
Marketing
Disaggregation of Revenue
Revenues from contracts with customers	46,645	89,598	200,911	394,189
Other income
Disaggregation of Revenue
Revenues from contracts with customers	1,481		3,348
Exploration and production | Natural gas sales
Disaggregation of Revenue
Revenues from contracts with customers	524,448	527,122	1,735,086	1,498,324
Exploration and production | Natural gas liquids sales (ethane)
Disaggregation of Revenue
Revenues from contracts with customers	26,488	56,185	92,378	115,947
Exploration and production | Natural gas liquids sales (C3+ NGLs)
Disaggregation of Revenue
Revenues from contracts with customers	258,470	282,084	810,228	712,477
Exploration and production | Oil sales
Disaggregation of Revenue
Revenues from contracts with customers	40,561	59,722	137,675	128,869
Gathering and compression | Gathering and compression
Disaggregation of Revenue
Revenues from contracts with customers		4,439	3,972	12,848
Water handling and treatment | Water handling and treatment
Disaggregation of Revenue
Revenues from contracts with customers		405	507	2,450
Marketing | Marketing
Disaggregation of Revenue
Revenues from contracts with customers	$ 46,645	$ 89,598	$ 200,911	$ 394,189