Revenues from Contracts with Customers - Disaggregation of Revenue by Identified Revenue Stream (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Disaggregation of Revenue [Line Items]
Total Revenue	$ 3,333,836
Natural gas sales
Disaggregation of Revenue [Line Items]
Total Revenue	2,137,573	[1]
NGLs sales
Disaggregation of Revenue [Line Items]
Total Revenue	940,378	[2]
Crude oil and condensate sales
Disaggregation of Revenue [Line Items]
Total Revenue	$ 255,885

[1] Natural gas sales revenue reported above includes $460.3 million of brokered revenues and $13.4 million of marketing revenue.

[2] NGLs sales revenue reported above includes $9.0 million of brokered revenues.