Summary of Significant Accounting Policies - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Interest, net of amount capitalized	$ 198,562	$ 260,959	$ 189,371
Income taxes, net	(1,710)	(3,675)	3,637
Changes in property, plant and equipment accruals	170,848	(274,219)	4,439
Increase in asset retirement costs and obligations	169,387	34,602	143,578
Increase in right-of-use lease assets and liabilities	113,350	0	0
Capitalization of non-cash equity share-based compensation	0	4,314	8,993
Assumption of net liabilities from current period acquisitions	0	0	10,004
Measurement period adjustments for prior period acquisitions	0	14,377	(14,315)
Mountain Valley Pipeline
Condensed Cash Flow Statements, Captions [Line Items]
Increase in capital contributions payable to Mountain Valley Pipeline, LLC	$ 0	$ 176,551	$ 94,263