Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 220,512	$ 1,425,815
Joint interest and other receivables	109,853	61,592
Prepaid expenses and other current assets	26,423	23,941
Inventory	83,225	65,286
Short-term restricted funds	228,533	90,440
Short-term investments	1,221,552	789,668
Total current assets	1,890,098	2,456,742
Property, plant, and equipment:
Oil and gas properties, successful efforts method of accounting, net of accumulated depletion of $-0-	1,411,999	1,094,464
Other property and equipment, net of accumulated depreciation and amortization of $3,865 and $2,533, as of September 30, 2013 and December 31, 2012, respectively	11,627	5,292
Total property, plant, and equipment, net	1,423,626	1,099,756
Long-term restricted funds	166,701	395,652
Long-term investments	200,597	36,267
Other assets	34,809	23,042
Total assets	3,715,831	4,011,459
Current liabilities:
Trade and other accounts payable	10,418	67,876
Accrued liabilities	163,056	44,061
Short-term contractual obligations	49,019	49,019
Total current liabilities	222,493	160,956
Long-term debt	1,024,445	991,191
Long-term contractual obligations	124,901	168,238
Other long-term liabilities	2,686	1,856
Total long-term liabilities	1,152,032	1,161,285
Stockholders' Equity:
Common stock, $0.01 par value per share; 2,000,000,000 shares authorized, 406,943,582 and 406,596,884 issued and outstanding as of September 30, 2013 and December 31, 2012, respectively	4,069	4,066
Additional paid-in capital	3,631,977	3,612,987
Accumulated deficit during the development stage	(1,294,740)	(927,835)
Total stockholders' equity	2,341,306	2,689,218
Total liabilities and stockholders' equity	$ 3,715,831	$ 4,011,459