Condensed Balance Sheets (unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets
Cash and cash equivalents	$ 5,519	$ 51,041
Accounts receivable - trade, net	138,228	122,855
Derivative instruments	3,626	5,596
Other current assets	32,114	30,833
Total current assets	179,487	210,325
Noncurrent assets
Oil and natural gas properties (successful efforts method)	4,957,390	4,813,659
Less accumulated depletion and amortization	(76,083)	(10,394)
Oil and natural gas properties, net	4,881,307	4,803,265
Other property and equipment	84,957	83,126
Less accumulated depreciation	(1,972)	(233)
Other property and equipment, net	82,985	82,893
Derivative instruments	2,660	2,511
Other noncurrent assets	9,699	8,051
Noncurrent assets excluding property total	12,359	10,562
Total noncurrent assets	4,976,651	4,896,720
Total assets	5,156,138	5,107,045
Current liabilities
Accounts payable and accrued expenses	250,684	264,271
Derivative instruments	16,209	20,393
Other accrued liabilities	28,887	28,993
Current portion of long-term debt	207,502	211,558
Total current liabilities	503,282	525,215
Noncurrent liabilities
Credit facility	1,173,175	1,173,175
Senior notes, net	915,121	916,428
Derivative instruments	891	4,649
Other noncurrent liabilities	188,484	192,091
Total noncurrent liabilities	2,277,671	2,286,343
Commitments and contingencies (Note 10)
Member's equity
Additional paid-in capital	2,315,460	2,315,460
Accumulated income (deficit)	59,725	(19,973)
Total member's equity	2,375,185	2,295,487
Total liabilities and member's equity	$ 5,156,138	$ 5,107,045