Consolidated Balance Sheets (Unaudited) (USD $) In Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 181,689	$ 23,743
Accounts receivable	108,271	70,368
Short-term investments	180,585	223,991
Inventory	47,488	34,959
Other current assets	10,470	7,796
Total current assets	528,503	360,857
Oil and natural gas properties, using the full cost method including Proved, net of accumulated depletion of $466,162 and $423,691	708,981	486,423
Unproved	265,002	182,933
Total oil and gas	973,983	669,356
Other property and equipment, net	75,075	42,837
Deferred loan fees	17,512	9,064
Other noncurrent assets	5,410	3,287
Total assets	1,600,483	1,085,401
Current liabilities:
Accounts payable	84,403	50,023
Royalties payable	67,436	42,155
Accrued drilling costs	116,616	61,067
Participant advances received	10,739	3,037
Derivative liabilities	14,400	9,442
Other current liabilities	14,213	10,821
Total current liabilities	307,807	176,545
Senior Notes	600,000	300,000
Other noncurrent liabilities	23,734	15,586
Commitments and contingencies (Note 3)
Stockholders' equity:
Common stock, $.01 par value, 180 million shares authorized, 116,736,145 and 116,564,182 shares issued and 116,442,586 and 116,289,180 shares outstanding at June 30, 2011 and December 31, 2010, respectively	1,168	1,166
Additional paid-in capital	769,164	765,326
Treasury stock, at cost; 293,559 and 275,002 shares at June 30, 2011 and December 31, 2010, respectively	(3,163)	(2,657)
Accumulated other comprehensive income (loss)	(60)	(9)
Retained earnings (deficit)	(98,167)	(170,556)
Total stockholders' equity	668,942	593,270
Total liabilities and stockholders' equity	$ 1,600,483	$ 1,085,401