CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 14,582	$ 66,192
Accounts receivable	25,981	35,654
Derivative instruments	395	5,192
Other current assets	8,894	6,756
Total current assets	49,852	113,794
Oil and natural gas properties, full cost method of accounting:
Proved, net of accumulated depletion of $8,575,255 and $8,460,589	737,260	753,079
Unproved	49,146	53,645
Net oil and natural gas properties	786,406	806,724
Other property and equipment, net of accumulated depreciation and amortization of $45,265 and $50,058	9,376	11,845
Net property and equipment	795,782	818,569
Deferred income taxes	444	2,230
Goodwill	134,434	134,434
Derivative instruments	363	400
Other assets	15,950	48,525
TOTAL ASSETS	996,825	1,117,952
Current liabilities:
Accounts payable and accrued liabilities	129,744	141,107
Accrued interest	6,653	6,654
Derivative instruments	13,503	4,542
Deferred income taxes	444	2,230
Other current liabilities	4,864	12,201
Total current liabilities	155,208	166,734
Long-term debt	800,163	800,179
Asset retirement obligations	21,821	22,629
Derivative instruments	1,940	0
Other liabilities	63,332	73,941
Total liabilities	1,042,464	1,063,483
Shareholders’ equity:
Preferred stock, none issued and outstanding	0	0
Common stock, 119,347,173 and 119,399,983 shares issued and outstanding	11,935	11,940
Capital surplus	2,558,271	2,554,997
Accumulated deficit	(2,605,794)	(2,502,070)
Accumulated other comprehensive loss	(10,051)	(10,398)
Total shareholders’ equity	(45,639)	54,469
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 996,825	$ 1,117,952