Supplemental Information on Natural Gas and Oil Exploration, Development and Production Activities (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2021

Extractive Industries [Abstract]

Capitalized Costs and Accumulated Depreciation, Depletion and Amortization

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

	December 31,
	2021			2020			2019
	(in thousands)
Natural gas and oil properties:
Properties subject to depletion	$	9,338,236		$	8,891,348		$	9,345,557
Unproved properties		837,334			859,766			868,180
Total		10,175,570			9,751,114			10,213,737
Accumulated depreciation, depletion and    amortization		(4,420,914	)		(4,064,305	)		(4,172,702	)
Net capitalized costs	$	5,754,656		$	5,686,809		$	6,041,035

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

Costs Incurred for Property Acquisition, Exploration and Development

Costs Incurred for Property Acquisition, Exploration and Development (a)

	December 31,
	2021		2020		2019
	(in thousands)
Acquisitions
Acreage purchases	$	21,942	$	26,166	$	57,324
Development		381,753		369,093		666,984
Exploration:
Drilling		6,329		7,709		—
Expense		22,048		31,376		35,117
Stock-based compensation expense		1,507		1,279		1,566
Gas gathering facilities:
Development		3,402		3,694		3,583
Subtotal		436,981		439,317		764,574
Asset retirement obligations		18,634		2,610		11,193
Total costs incurred	$	455,615	$	441,927	$	775,767

(a) Includes cost incurred whether capitalized or expensed.

Proved Developed and Undeveloped Reserves

	Natural Gas			NGLs			Crude Oil and Condensate			Natural Gas Equivalents
	(Mmcf)			(Mbbls)			(Mbbls)			(Mmcfe) (a)
Proved developed and undeveloped reserves:
Balance, December 31, 2018		12,027,702			921,594			85,856			18,072,406
Revisions		33,122			57,311			(12,320	)		303,068
Extensions, discoveries and additions		959,901			26,505			7,057			1,161,274
Property sales		(327,634	)		(28,324	)		(2,371	)		(511,811	)
Production		(578,114	)		(38,850	)		(3,690	)		(833,354	)
Balance, December 31, 2019		12,114,977			938,236			74,532			18,191,583
Revisions		(789,992	)		42,741			(12,444	)		(608,211	)
Extensions, discoveries and additions		1,007,415			38,298			4,512			1,264,282
Property sales		(609,311	)		(30,317	)		(6,145	)		(828,084	)
Production		(574,529	)		(37,492	)		(2,829	)		(816,456	)
Balance, December 31, 2020		11,148,560			951,466			57,626			17,203,114
Revisions		(311,410	)		16,845			(7,089	)		(252,876	)
Extensions, discoveries and additions		1,155,952			69,367			5,103			1,602,769
Production		(541,021	)		(36,373	)		(3,044	)		(777,523	)
Balance, December 31, 2021		11,452,081			1,001,305			52,596			17,775,484
Proved developed reserves:
December 31, 2019		6,486,211			535,007			34,369			9,902,468
December 31, 2020		6,350,057			550,771			22,976			9,792,540
December 31, 2021		6,809,849			577,506			23,833			10,417,887
Proved undeveloped reserves:
December 31, 2019		5,628,766			403,229			40,163			8,289,115
December 31, 2020		4,798,503			400,695			34,650			7,410,574
December 31, 2021		4,642,232			423,798			28,762			7,357,597

(a) Oil and NGLs volumes are converted to mcfe at the rate of one barrel equals six mcf based upon the approximate relative energy content of oil to natural gas, which is not indicative of the relationship between oil and natural gas prices.

Changes in Proved Undeveloped Reserves

The following details the changes in proved undeveloped reserves for 2021 (Mmcfe):

Beginning proved undeveloped reserves at December 31, 2020	7,410,574
Undeveloped reserves transferred to developed	(1,199,544	)
Revisions (a)	(393,561	)
Extension and discoveries	1,540,128
Ending proved undeveloped reserves at December 31, 2021	7,357,597

(a) Includes 1.3 Tcfe of proved undeveloped reserves removed and deferred due to the five-year rule which can be included in our future proved reserves as these locations are added back to our five-year development plan.

Standardized Measure of Discounted Future Net Cash Flows

The standardized measure of discounted future net cash flows relating to proved natural gas, NGLs, crude oil and condensate reserves is as follows and excludes cash flows associated with derivatives outstanding at each of the respective reporting dates. Future cash inflows are net of third-party transportation, gathering and compression expense.

	As of December 31,
	2021			2020
	(in thousands)
Future cash inflows	$	69,403,611		$	35,820,758
Future costs:
Production		(27,015,321	)		(23,281,268	)
Development (a)		(2,469,028	)		(2,744,539	)
Future net cash flows before income taxes		39,919,262			9,794,951
Future income tax expense		(8,146,832	)		(1,240,011	)
Total future net cash flows before 10% discount		31,772,430			8,554,940
10% annual discount		(19,287,204	)		(5,708,618	)
Standardized measure of discounted future net cash    flows	$	12,485,226		$	2,846,322

(a) 2021 includes $308.5 million of undiscounted future asset retirement costs as of December 31, 2021, using current estimates of future abandonment costs.

Changes in Discounted Future Net Cash Flows

The following table summarizes changes in the standardized measure of discounted future net cash flows.

	December 31,
	2021			2020			2019
	(in thousands)
Revisions of previous estimates:
Changes in prices and production costs	$	11,600,850		$	(4,868,371	)	$	(6,560,107	)
Revisions in quantities		577,737			(345,073	)		(12,741	)
Changes in future development and abandonment    costs		(53,818	)		107,899			104,585
Net change in income taxes		(2,248,161	)		797,816			1,125,639
Accretion of discount		298,077			756,083			1,317,349
Additions to proved reserves from extensions,    discoveries and improved recovery		1,423,510			280,441			552,710
Natural gas, NGLs and oil sales, net of production    costs		(1,934,254	)		(402,450	)		(881,883	)
Actual development costs incurred during the    period		399,681			384,530			676,520
Sales of reserves in place		—			(394,125	)		(688,937	)
Timing and other		(424,718	)		(99,001	)		(120,156	)
Net change for the year		9,638,904			(3,782,251	)		(4,487,021	)
Beginning of year		2,846,322			6,628,573			11,115,594
End of year	$	12,485,226		$	2,846,322		$	6,628,573