Consolidated statements of cash flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:
Net income	$ 64,295	$ 49,764
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income tax expense	35,511	31,970
Depletion, depreciation and amortization	166,605	187,346
Bad debt expense	0	653
Non-cash stock-based compensation, net of amount capitalized	16,919	13,556
Accretion of asset retirement obligations	1,279	1,154
Loss on derivatives, net	1,447	2,732
Cash settlements (paid) received for matured derivatives, net	(1,320)	588
Cash settlements received for early terminations of derivatives, net	76,660	5,366
Change in net present value of deferred premiums paid for derivatives	170	384
Cash premiums paid for derivatives	(5,599)	(7,920)
Amortization of deferred loan costs	3,823	3,905
Write-off of deferred loan costs	124	1,502
Other	2,734	(662)
(Increase) decrease in accounts receivable	(26,449)	5,873
Increase in other assets	(8,656)	(1,383)
Increase (decrease) in accounts payable	39,456	(17,724)
Increase (decrease) in undistributed revenues and royalties	14,105	(5,780)
Decrease in other accrued liabilities	(7,908)	(1,406)
Increase in other noncurrent liabilities	2,373	570
Increase in fair value of performance unit awards	767	4,950
Net cash provided by operating activities	376,336	275,438
Capital expenditures:
Acquisition of oil and natural gas properties	(6,493)	(33,710)
Acquisition of mineral interests	(7,305)	0
Oil and natural gas properties	(925,121)	(538,395)
Midstream service assets	(45,263)	(15,394)
Other fixed assets	(13,612)	(13,874)
Investment in equity method investee	(37,581)	(3,287)
Proceeds from dispositions of capital assets, net of costs	1,627	429,702
Net cash used in investing activities	(1,033,748)	(174,958)
Cash flows from financing activities:
Borrowings on Senior Secured Credit Facility	75,000	230,000
Payments on Senior Secured Credit Facility	0	(395,000)
Issuance of January 2022 Notes	450,000	0
Proceeds from issuance of common stock, net of offering costs	0	298,104
Purchase of treasury stock	(4,075)	(1,478)
Proceeds from exercise of employee stock options	1,885	654
Payments for loan costs	(7,791)	(714)
Net cash provided by financing activities	515,019	131,566
Net (decrease) increase in cash and cash equivalents	(142,393)	232,046
Cash and cash equivalents at beginning of period	198,153	33,224
Cash and cash equivalents at end of period	$ 55,760	$ 265,270