Consolidated Statements Of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
OIL AND GAS REVENUES	$ 144,329	$ 96,197	$ 390,454	$ 260,730
COSTS AND EXPENSES
Lease operating	12,934	7,145	34,926	22,599
Production tax	5,590	3,449	14,687	9,676
Ad valorem tax	2,125	2,327	6,848	8,238
Depreciation, depletion and amortization	55,234	46,518	151,232	121,459
General and administrative (inclusive of stock-based compensation expense of $9,872 and $5,091 for the three months ended September 30, 2013 and 2012, respectively, and $19,338 and $10,622 for the nine months ended September 30, 2013 and 2012, respectively)	19,715	12,354	53,722	36,974
Accretion related to asset retirement obligations	128	86	355	280
TOTAL COSTS AND EXPENSES	95,726	71,879	261,770	199,226
OPERATING INCOME	48,603	24,318	128,684	61,504
OTHER INCOME AND EXPENSES
Gain (loss) on derivative instruments, net	(27,658)	(14,718)	(16,486)	26,975
Interest expense	(20,887)	(18,074)	(64,158)	(51,298)
Capitalized interest	7,485	5,917	21,791	17,951
Other income, net	28	20	95	254
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	7,571	(2,537)	69,926	55,386
INCOME TAX (EXPENSE) BENEFIT	(1,859)	592	(25,853)	(20,972)
NET INCOME (LOSS) FROM CONTINUING OPERATIONS	5,712	(1,945)	44,073	34,414
NET INCOME (LOSS) FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES	(1,191)	1,015	23,599	2,583
NET INCOME (LOSS)	$ 4,521	$ (930)	$ 67,672	$ 36,997
NET INCOME (LOSS) PER COMMON SHARE - BASIC
Net income from continuing operations - basic (in dollars per share)	$ 0.14	$ (0.05)	$ 1.10	$ 0.87
Net income from discontinued operations - basic (in dollars per share)	$ (0.03)	$ 0.03	$ 0.59	$ 0.07
Net income per share, basic (in dollars per share)	$ 0.11	$ (0.02)	$ 1.69	$ 0.94
NET INCOME (LOSS) PER COMMON SHARE - DILUTED
Net income from continuing operations - diluted (in dollars per share)	$ 0.14	$ (0.05)	$ 1.09	$ 0.86
Net income from discontinued operations - diluted (in dollars per share)	$ (0.03)	$ 0.03	$ 0.58	$ 0.07
Net income per share, diluted (in dollars per share)	$ 0.11	$ (0.02)	$ 1.67	$ 0.93
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING
Basic (in shares)	40,386	39,634	40,083	39,559
Diluted (in shares)	40,927	39,634	40,601	39,992

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 410

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 410

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)(3)

-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 143

-Paragraph 22

-Subparagraph c(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 143

-Paragraph 13, 14

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.