CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (in thousands) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income (loss)		$ 334,598	$ (45,473)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Net (gain) loss on divestiture activity		(424,870)	129,670
Depletion, depreciation, amortization, and asset retirement obligation liability accretion		282,238	291,044
Abandonment and impairment of unproved properties		17,560	157
Stock-based compensation expense		10,676	9,813
Net derivative (gain) loss		71,278	(169,963)
Derivative settlement gain (loss)		(61,193)	16,310
Amortization of debt discount and deferred financing costs		7,750	8,679
Loss on extinguishment of debt		0	35
Deferred income taxes		97,505	(30,790)
Other, net		(2,302)	4,464
Net change working capital		(21,722)	28,182
Net cash provided by operating activities		311,518	242,128
Cash flows from investing activities:
Net proceeds from the sale of oil and gas properties		742,215	766,247
Capital expenditures		(723,319)	(366,743)
Acquisition of proved and unproved oil and gas properties		(24,615)	(88,140)
Net cash provided by (used in) investing activities		(5,719)	311,364
Cash flows from financing activities:
Proceeds from credit facility		0	406,000
Repayment of credit facility		0	(406,000)
Cash paid to repurchase Senior Notes		0	(2,344)
Cash paid for extinguishment of debt		0	(13)
Net proceeds from sale of common stock		1,881	1,738
Dividends paid		(5,584)	(5,563)
Other, net		(133)	(161)
Net cash used in financing activities		(3,836)	(6,343)
Net change in cash, cash equivalents, and restricted cash	[1]	301,963	547,149
Cash, cash equivalents, and restricted cash at beginning of period	[1]	313,943	12,372
Cash, cash equivalents, and restricted cash at end of period	[1]	615,906	559,521
Operating activities:
Cash paid for interest, net of capitalized interest		(77,803)	(83,493)
Net cash (paid) refunded for income taxes		207	(8,220)
Investing activities:
Changes in capital expenditure accruals and other		62,167	44,770
Supplemental non-cash investing activities:
Carrying value of properties exchanged		0
Supplemental non-cash financing activities:
Non-cash (gain) loss on extinguishment of debt, net		$ 0	$ 22

[1] (1) Refer to Note 1 - Summary of Significant Accounting Policies for a reconciliation of cash, cash equivalents, and restricted cash reported to the amounts reported within the accompanying unaudited condensed consolidated balance sheets (“accompanying balance sheets”).