Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Intangible Drilling Cost	$ 4,764,284	$ 4,688,497
Gas Gathering Equipment	2,477,889	2,463,866
Proved Gas Properties	1,209,521	1,208,046
Gas Wells and Related Equipment	1,067,318	1,042,000
Unproved Gas Properties	756,151	755,590
Surface Land and Other Equipment	225,074	226,285
Other	191,279	187,722
Total Property, Plant and Equipment	10,691,516	10,572,006
Less: Accumulated Depreciation, Depletion and Amortization	3,622,413	3,435,431
Total Property, Plant and Equipment—Net	$ 7,069,103	$ 7,136,575