Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
OPERATING ACTIVITIES:
Net income (loss)	$ (553,828)	$ (39,767)	$ 117,848
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion, and amortization	275,573	243,605	209,257
Impairments (Note 3)	625,716	147,884	0
Amortization of debt issuance costs and debt discount (Note 8)	2,241	2,198	2,159
(Gain) loss on derivatives (Note 14)	(4,225)	3,184	(14,732)
Derivative Instruments Not Designated Amount Paid (Received) During Period	16,196	(22,803)	173
(Gain) loss on disposition of assets	3,502	(704)	(327)
Deferred tax benefit (Note 10)	(131,045)	(10,865)	(57,683)
Employee stock compensation plans	12,932	22,899	17,747
Bad debt expense	527	81	348
ARO liability accretion (Note 9)	2,343	2,393	2,886
Contract assets and liabilities, net (Note 4)	2,577	4,970	0
Other, net	1,766	2,032	(865)
Changes in operating assets and liabilities increasing (decreasing) cash:
Accounts receivable	33,323	(7,967)	(27,941)
Materials and supplies	24	32	2,835
Prepaid expenses and other	195	(4,950)	1,527
Accounts payable	(15,558)	28,013	8,192
Accrued liabilities	3,142	(5,465)	6,996
Income taxes	298	(1,993)	38
Contract advances	(1,149)	(90)	1,630
Net cash provided by operating activities	269,396	352,747	270,088
INVESTING ACTIVITIES:
Capital expeditures	(406,665)	(446,282)	(255,553)
Producing property and other oil and natural gas acquisitions	(3,653)	(29,970)	(58,026)
Payments to Acquire Other Property, Plant, and Equipment	(16,109)	0	0
Proceeds from disposition of property and equipment	31,864	25,910	21,713
Other	0	0	(1,500)
Net cash used in investing activities	(394,563)	(450,342)	(293,366)
FINANCING ACTIVITIES:
Borrowings under line of credit	493,500	99,100	343,900
Payments under line of credit	(368,800)	(277,100)	(326,700)
Payments on finance leases	(4,001)	(3,843)	(3,694)
Proceeds from common stock issued, net of issue costs (Note 19)	0	0	18,623
Proceeds from investments of non-contolling interests	0	300,000	0
Payments Related to Tax Withholding for Share-based Compensation	(4,158)	(4,988)	(4,132)
Transaction costs associated with sale of non-controlling interest	0	(2,503)	0
Payments to Noncontrolling Interests	(918)	0	0
Bank overdrafts (Note 3)	3,663	(7,320)	(4,911)
Net cash provided by financing activities	119,286	103,346	23,086
Net increase (decrease) in cash and cash equivalents	(5,881)	5,751	(192)
Cash and cash equivalents, beginning of year	6,452	701	893
Cash and cash equivalents, end of year	571	6,452	701
Supplemental disclosure of cash flow information:
Interest paid (net of capitalization)	33,694	34,535	33,931
Income taxes	273	3,600	0
Changes in accounts payable and accrued liabilities related to purchases of property, plant, and equipment	54,549	(18,119)	(20,574)
Non-cash reductions to oil and natural gas properties related to asset retirement obligations	$ (76)	$ 7,629	$ 3,613