CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating Activities
Net income (loss)	$ 13,743	$ 1,766	$ (28,525)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Equity in (income) loss of joint venture	(2,187)	473	0
Change in derivative fair value	(7,680)	(10,451)	25,740
Monetization of derivative contracts	0	0	26,736
Depreciation, depletion, and amortization	16,194	16,212	17,886
Impairment	0	4,787	0
Accretion of future site restoration	452	516	558
Amortization of deferred financing fees	1,762	2,479	1,326
Stock-based compensation	1,987	1,560	1,239
Registration fees previously capitalized	0	0	2,210
Loss on disposal of assets	0	0	289
Other non-cash transactions	0	24	78
Changes in operating assets and liabilities:
Accounts receivable	(182)	(3,976)	(803)
Other assets and liabilities	(17)	(113)	(7)
Accounts payable	756	14,210	(1,545)
Accrued expenses	(333)	(3,385)	(1,046)
Net cash provided by operating activites	24,495	24,102	44,136
Investing Activities
Capital expenditures, including purchases and development of properties	(79,012)	(36,448)	(16,471)
Proceeds from the sale of oil and gas properties	8,457	21,400	2,375
Net cash used in investing activities	(70,555)	(15,048)	(14,096)
Financing Activities
Proceeds from exercise of stock options and warrants	83	69	203
Proceeds from issuance of common stock, net of offering costs	62,346	0	0
Transaction costs on exchange of partnership units	0	0	(2,557)
Proceeds from long-term borrowings	50,500	3,000	13,500
Payments on long-term borrowings	(65,153)	(13,641)	(32,736)
Partnership distribution to non-controlling interest	0	0	(2,257)
Deferred financing fees	(1,758)	(169)	(5,687)
Other	(52)	(75)	(569)
Net cash (used in) provided by financing activities	45,966	(10,816)	(30,103)
Effect of exchange rate changes on cash	(5)	0	0
Decrease in cash	(99)	(1,762)	(63)
Cash at beginning of year	99	1,861	1,924
Cash at end of year	0	99	1,861
Supplemental disclosures of cash flow information:
Interest paid	4,514	8,876	10,575
Non-Cash Investing Activities:
Asset retirement obligation cost and liabilities	(8)	(83)	(80)
Asset retirement obligations associated with property acquisitions and dispositions	306	(2,735)	2
Properties contributed to joint venture	$ 0	$ 24,500	$ 0