Capitalized Costs and Accumulated Depreciation, Depletion and Amortization (Tables)

3 Months Ended

Mar. 31, 2021

Extractive Industries [Abstract]

Capitalized Costs and Accumulated Depreciation, Depletion and Amortization

	March 31, 2021			December 31, 2020
	(in thousands)
Natural gas properties:
Properties subject to depletion	$	8,991,165		$	8,891,348
Unproved properties		862,741			859,766
Total		9,853,906			9,751,114
Accumulated depletion and depreciation		(4,150,811	)		(4,064,305	)
Net capitalized costs	$	5,703,095		$	5,686,809

^(a) Includes capitalized asset retirement costs and the associated accumulated amortization.