CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating activities:
Net income	$ 27,151	$ 166,195
Adjustments to reconcile net income to net cash provided from
Deferred income tax expense	2,521	29,361
Depletion, depreciation and amortization and impairment of proved properties	88,383	179,986
Abandonment and impairment of unproved properties	3,029	5,413
Derivative fair value loss (income)	57,879	(233,175)
Cash settlements on derivative financial instruments	(39,395)	99,929
Divestiture contract obligation accretion	12,995	0
Allowance for bad debt	0	400
Amortization of deferred financing costs and other	2,081	1,657
Deferred and stock-based compensation	30,054	476
Loss (gain) on the sale of assets	1,860	(122,099)
Loss (gain) on early extinguishment of debt	35	(12,923)
Changes in working capital:
Accounts receivable	(33,146)	84,345
Other current assets	122	(4,432)
Accounts payable	34,418	18,660
Accrued liabilities and other	(78,735)	(89,287)
Net cash provided from operating activities	109,252	124,506
Investing activities:
Additions to natural gas properties	(99,233)	(129,962)
Additions to field service assets	(487)	(896)
Acreage purchases	(11,849)	(10,811)
Proceeds from disposal of assets	8	1,059
Purchases of marketable securities held by the deferred compensation plan	(3,172)	(7,648)
Proceeds from the sales of marketable securities held by the deferred compensation plan	2,333	8,393
Net cash used in investing activities	(112,400)	(139,865)
Financing activities:
Borrowings on credit facilities	478,000	543,000
Repayments on credit facilities	(1,056,000)	(463,000)
Issuance of senior notes	600,000	550,000
Repayment of senior or senior subordinated notes	0	(580,099)
Treasury stock purchases	0	(22,548)
Debt issuance costs	(8,559)	(8,538)
Taxes paid for shares withheld	(9,097)	(1,554)
Change in cash overdrafts	(1,646)	(1,933)
Proceeds from the sales of common stock held by the deferred compensation plan	441	13
Net cash provided from financing activities	3,139	15,341
Decrease in cash and cash equivalents	(9)	(18)
Cash and cash equivalents at beginning of period	458	546
Cash and cash equivalents at end of period	$ 449	$ 528