CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Statement of Cash Flows [Abstract]
Net income	$ 65,607		$ 16,727
Adjustments to reconcile net income to net cash provided by operating activities:
(Gain) loss on divestiture activity	2,958		(574)
Depletion, depreciation, amortization, and asset retirement obligation liability accretion	177,215		198,709
Exploratory dry hole expense	0		159
Impairment of properties	2,801		21,521
Stock-based compensation expense	6,344		8,113
Change in Net Profits Plan liability	(1,776)		(1,925)
Derivative loss	97,662	[1]	30,572	[1]
Derivative cash settlement (loss) gain	(28,940)	[2]	11,792	[2]
Amortization of debt discount and deferred financing costs	1,477		1,077
Deferred income taxes	38,374		10,280
Plugging and abandonment	(1,325)		(1,378)
Other	(3,103)		1,836
Changes in current assets and liabilities:
Accounts receivable	9,347		(22,164)
Prepaid expenses and other	885		605
Accounts payable and accrued expenses	(61,882)		5,794
Net Cash Provided by Operating Activities	299,728		282,292
Cash flows from investing activities:
Net proceeds from sale of oil and gas properties	1,979		4,307
Capital expenditures	(351,739)		(381,185)
Other	4,227		(2,025)
Net cash used in investing activities	(345,533)		(378,903)
Cash flows from financing activities:
Proceeds from credit facility	0		223,500
Repayment of credit facility	0		(133,500)
Other	(8)		772
Net cash provided by (used in) financing activities	(8)		90,772
Net change in cash and cash equivalents	(45,813)		(5,839)
Cash and cash equivalents at beginning of period	282,248		5,926
Cash and cash equivalents at ending of period	236,435		87
Supplemental schedule of additional cash flow information and noncash investing and financing activities:
Cash paid for interest, net of capitalized interest	(37,851)		(24,721)
Net cash refunded for income taxes	14		165
Assets Held for Sale
Assets Held-for-sale Reasonably Certain Period for Sale	1
Oil and gas properties held for sale net of accumulated depletion, depreciation and amortization of $31,776 in 2014 and $7,390 in 2013	42,276
Asset retirement obligation associated with oil and gas properties held for sale	$ 4,526

[1] (2) Total derivative loss is reported in the derivative loss line item on the condensed consolidated statements of cash flows within cash provided by operating activities.

[2] (1) Total derivative cash settlement loss (gain) is reported in the derivative cash settlement (loss) gain line item on the condensed consolidated statements of cash flows within net cash provided by operating activities.