Consolidated Balance Sheets (Unaudited) (USD $) In Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 91,544	$ 23,743
Accounts receivable	131,332	70,368
Short-term investments	114,738	223,991
Inventory	53,238	34,959
Other current assets	26,106	7,796
Total current assets	416,958	360,857
Oil and natural gas properties, using the full cost method including Proved, net of accumulated depletion of $495,115 and $423,691	761,999	486,423
Unproved	433,848	182,933
Total oil and gas	1,195,847	669,356
Other property and equipment, net	95,887	42,837
Deferred loan fees	17,159	9,064
Other noncurrent assets	20,876	3,287
Total assets	1,746,727	1,085,401
Current liabilities:
Accounts payable	89,840	50,023
Royalties payable	82,992	42,155
Accrued drilling costs	155,888	61,067
Participant advances received	5,511	3,037
Derivative liabilities	69	9,442
Other current liabilities	27,315	10,821
Total current liabilities	361,615	176,545
Senior Notes	600,000	300,000
Other noncurrent liabilities	12,074	15,586
Commitments and contingencies (Note 3)
Stockholders' equity:
Common stock, $.01 par value, 180 million shares authorized, 116,800,125 and 116,564,182 shares issued and 116,498,651 and 116,289,180 shares outstanding at September 30, 2011 and December 31, 2010, respectively	1,168	1,166
Additional paid-in capital	770,920	765,326
Treasury stock, at cost; 301,474 and 275,002 shares at September 30, 2011 and December 31, 2010, respectively	(3,388)	(2,657)
Accumulated other comprehensive income (loss)	(8)	(9)
Retained earnings (deficit)	4,346	(170,556)
Total stockholders' equity	773,038	593,270
Total liabilities and stockholders' equity	$ 1,746,727	$ 1,085,401