Fresh Start Accounting - Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Feb. 09, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 1,079	$ 130	$ 905	$ 40
Restricted cash				86
Accounts receivable, net				843
Short-term derivative assets	637	34		0
Other current assets				61
Total current assets	2,609	2,698		1,030
Property and equipment:
Proved natural gas and oil properties	11,468	11,096		4,686
Unproved properties	1,806	2,022		483
Other property and equipment	497	500		499
Total property and equipment	13,771	13,618		5,668
Less: accumulated depreciation, depletion and amortization	(3,674)	(2,431)		0
Property and equipment held for sale, net				2
Total property and equipment, net	10,097	11,187		5,670
Other long-term assets	663	185		114
Total assets	14,376	15,468		6,814
Current liabilities:
Accounts payable	425	603		415
Current maturities of long-term debt, net				0
Accrued interest	39	42		0
Short-term derivative liabilities	3	432		398
Other current liabilities	847	1,627		769
Total current liabilities	1,314	2,704		1,582
Net impact to long-term debt, net	1,950			1,313
Long-term derivative liabilities	9	174		90
Asset retirement obligations, net of current portion	265	323		236
Other long-term liabilities	31	50		7
Liabilities subject to compromise				0
Total liabilities	3,647	6,344		3,228
Contingencies and commitments (Note 7)
Stockholders’ equity (deficit):
Predecessor preferred stock				0
Predecessor additional paid-in capital	5,754	5,724		0
Successor common stock	1	1		1
Successor additional paid-in-capital				3,585
Accumulated other comprehensive income				0
Retained earnings	4,974	3,399		0
Total stockholders' equity	10,729	9,124	$ 5,671	3,586	$ (5,341)
Total liabilities and stockholders' equity	$ 14,376	$ 15,468		6,814
Predecessor
Current assets:
Cash and cash equivalents				243
Restricted cash				0
Accounts receivable, net				861
Short-term derivative assets				0
Other current assets				66
Total current assets				1,170
Property and equipment:
Proved natural gas and oil properties				25,794
Unproved properties				1,546
Other property and equipment				1,755
Total property and equipment				29,095
Less: accumulated depreciation, depletion and amortization				(23,877)
Property and equipment held for sale, net				9
Total property and equipment, net				5,227
Other long-term assets				198
Total assets				6,595
Current liabilities:
Accounts payable				391
Current maturities of long-term debt, net				1,929
Accrued interest				4
Short-term derivative liabilities				398
Other current liabilities				645
Total current liabilities				3,367
Net impact to long-term debt, net				0
Long-term derivative liabilities				90
Asset retirement obligations, net of current portion				139
Other long-term liabilities				5
Liabilities subject to compromise				9,574
Total liabilities				13,175
Contingencies and commitments (Note 7)
Stockholders’ equity (deficit):
Predecessor preferred stock				1,631
Predecessor additional paid-in capital				16,940
Successor common stock				0
Successor additional paid-in-capital				0
Accumulated other comprehensive income				48
Retained earnings				(25,199)
Total stockholders' equity				(6,580)
Total liabilities and stockholders' equity				6,595
Reorganization Adjustments
Current assets:
Cash and cash equivalents				(203)
Restricted cash				86
Accounts receivable, net				(18)
Short-term derivative assets				0
Other current assets				(5)
Total current assets				(140)
Property and equipment:
Proved natural gas and oil properties				0
Unproved properties				0
Other property and equipment				0
Total property and equipment				0
Less: accumulated depreciation, depletion and amortization				0
Property and equipment held for sale, net				0
Total property and equipment, net				0
Other long-term assets				0
Total assets				(140)
Current liabilities:
Accounts payable				24
Current maturities of long-term debt, net				(1,929)
Accrued interest				(4)
Short-term derivative liabilities				0
Other current liabilities				124
Total current liabilities				(1,785)
Net impact to long-term debt, net				1,261
Long-term derivative liabilities				0
Asset retirement obligations, net of current portion				0
Other long-term liabilities				2
Liabilities subject to compromise				(9,574)
Total liabilities				(10,096)
Contingencies and commitments (Note 7)
Stockholders’ equity (deficit):
Predecessor preferred stock				(1,631)
Predecessor additional paid-in capital				(16,940)
Successor common stock				1
Successor additional paid-in-capital				3,585
Accumulated other comprehensive income				0
Retained earnings				24,941
Total stockholders' equity				9,956
Total liabilities and stockholders' equity				(140)
Reorganization, Chapter 11, Fresh-Start Adjustment
Current assets:
Cash and cash equivalents				48
Restricted cash				8
Accounts receivable, net				0
Short-term derivative assets				0
Other current assets				0
Total current assets				0
Property and equipment:
Proved natural gas and oil properties				(21,108)
Unproved properties				(1,063)
Other property and equipment				(1,256)
Total property and equipment				(23,427)
Less: accumulated depreciation, depletion and amortization				23,877
Property and equipment held for sale, net				(7)
Total property and equipment, net				443
Other long-term assets				(84)
Total assets				359
Current liabilities:
Accounts payable				0
Current maturities of long-term debt, net				0
Accrued interest				0
Short-term derivative liabilities				0
Other current liabilities				0
Total current liabilities				0
Net impact to long-term debt, net				52
Long-term derivative liabilities				0
Asset retirement obligations, net of current portion				97
Other long-term liabilities				0
Liabilities subject to compromise				0
Total liabilities				149
Contingencies and commitments (Note 7)
Stockholders’ equity (deficit):
Predecessor preferred stock				0
Predecessor additional paid-in capital				0
Successor common stock				0
Successor additional paid-in-capital				0
Accumulated other comprehensive income				(48)
Retained earnings				258
Total stockholders' equity				210
Total liabilities and stockholders' equity				$ 359