Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Operating activities
Net (loss) income	$ (2,875)	$ (20,443)
Adjustments to reconcile net loss to net cash provided by operating activities
Unrealized (gain) loss on derivatives	(11,844)	1,336
Depletion, depreciation and amortization	31,119	15,290
Accretion of asset retirement obligations	111	96
Full-cost ceiling impairment	33,205	35,673
Stock option and grant expense	(333)	159
Restricted stock and restricted stock units expense	161	22
Deferred income tax benefit	(649)	(6,906)
Loss on asset sales and inventory impairment	60
Changes in operating assets and liabilities
Accounts receivable	(2,761)	(3,526)
Lease and well equipment inventory	(98)	(1)
Prepaid expenses	(385)	366
Other assets	59
Accounts payable, accrued liabilities and other current liabilities	1,687	(3,330)
Royalties payable	3,642	1,643
Advances from joint interest owners		(723)
Other long-term liabilities	427	(125)
Net cash provided by operating activities	51,526	19,531
Investing activities
Oil and natural gas properties capital expenditures	(134,425)	(89,632)
Expenditures for other property and equipment	(3,521)	(1,722)
Purchases of certificates of deposit	(266)	(2,663)
Maturities of certificates of deposit	1,335	2,928
Net cash used in investing activities	(136,877)	(91,089)
Financing activities
Repayments of borrowings under Credit Agreement	(123,000)
Borrowings under Credit Agreement	70,000	60,000
Proceeds from issuance of common stock	146,510	592
Swing sale profit contribution	24
Cost to issue equity	(11,599)	(758)
Proceeds from stock options exercised	2,660	725
Payment of dividends - Class B	(96)	(137)
Net cash provided by financing activities	84,499	60,422
Decrease in cash and cash equivalents	(852)	(11,136)
Cash and cash equivalents at beginning of period	10,284	21,059
Cash and cash equivalents at end of period	$ 9,432	$ 9,923