Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue
Total revenues from contracts with customers	$ 498,772	$ 900,527	$ 1,213,973	$ 2,172,140
Gain on derivatives not designated as hedges	26,426	407,635	415,862	275,639
Net marketing services and other	1,876	2,090	4,296	5,646
Total operating revenues	527,074	1,310,252	1,634,131	2,453,425
Natural gas sales
Disaggregation of Revenue
Total revenues from contracts with customers	468,216	843,867	1,141,446	2,037,716
NGLs sales
Disaggregation of Revenue
Total revenues from contracts with customers	28,761	46,520	64,517	116,124
Oil sales
Disaggregation of Revenue
Total revenues from contracts with customers	1,795	10,140	8,010	18,300
Net marketing services and other
Disaggregation of Revenue
Net marketing services and other	$ 1,876	$ 2,090	$ 4,296	$ 5,646