Revenues from Contracts with Customers - Disaggregation of Revenue by Identified Revenue Stream (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Total Revenue		$ 684,405	$ 382,849	$ 1,368,316	$ 843,594
Natural Gas, NGLs and Oil Sales
Disaggregation of Revenue [Line Items]
Total Revenue		621,855	349,258	1,225,202	781,354
Natural Gas, NGLs and Oil Sales | Natural gas sales
Disaggregation of Revenue [Line Items]
Total Revenue		321,565	214,207	657,366	467,456
Natural Gas, NGLs and Oil Sales | NGLs sales
Disaggregation of Revenue [Line Items]
Total Revenue		255,533	124,383	485,941	267,622
Natural Gas, NGLs and Oil Sales | Oil sales
Disaggregation of Revenue [Line Items]
Total Revenue		44,757	10,668	81,895	46,276
Brokered Natural Gas, Marketing and Other
Disaggregation of Revenue [Line Items]
Total Revenue		62,550	33,591	143,114	62,240
Brokered Natural Gas, Marketing and Other | Natural gas sales
Disaggregation of Revenue [Line Items]
Total Revenue		60,778	30,309	130,240	55,184
Brokered Natural Gas, Marketing and Other | NGLs sales
Disaggregation of Revenue [Line Items]
Total Revenue		722	1,006	1,148	2,146
Brokered Natural Gas, Marketing and Other | Other marketing revenue
Disaggregation of Revenue [Line Items]
Total Revenue	[1]	$ 1,050	$ 2,276	$ 11,726	$ 4,910

[1] The six months ended June 30, 2021 includes $8.8 million received as part of a capacity release agreement.