CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues
Crude oil	$ 347,407	$ 229,572	$ 119,582
Natural gas liquids (NGLs)	30,748	31,051	43,394
Natural gas	52,538	49,861	137,070
Gain (loss) on sales of property and equipment, net	(266)	4,282	3,570
Other	1,041	2,383	2,389
Total revenues	431,468	317,149	306,005
Operating expenses
Lease operating	35,461	31,266	36,988
Gathering, processing and transportation	12,839	14,196	15,157
Production and ad valorem taxes	22,404	10,634	13,690
General and administrative	53,998	45,900	48,328
Exploration	20,994	34,092	78,943
Depreciation, depletion and amortization	245,594	206,336	162,534
Impairments	132,224	104,484	104,688
Loss on firm transportation commitment	0	17,332	0
Other	0	0	1,096
Total operating expenses	523,514	464,240	461,424
Operating loss	(92,046)	(147,091)	(155,419)
Other income (expense)
Interest expense	(78,841)	(59,339)	(56,216)
Loss on extinguishment of debt	(29,174)	(3,164)	(25,421)
Derivatives	(20,852)	36,187	15,651
Other	147	116	335
Loss before income taxes	(220,766)	(173,291)	(221,070)
Income tax benefit	77,696	68,702	88,155
Net loss	(143,070)	(104,589)	(132,915)
Preferred stock dividends	(6,900)	(1,687)	0
Net loss attributable to common shareholders	$ (149,970)	$ (106,276)	$ (132,915)
Net loss per share:
Net loss (in dollars per share)	$ (2.41)	$ (2.22)	$ (2.90)
Net loss (in dollars per share)	$ (2.41)	$ (2.22)	$ (2.90)
Weighted average shares outstanding - basic	62,335	47,919	45,784
Weighted average shares outstanding - diluted	62,335	47,919	45,784