Callon Petroleum (CPE) 10-Q 5 Aug 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Jul. 31, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	CALLON PETROLEUM CO
Entity Central Index Key	928,022
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		66,279,074

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 2,028	$ 968
Accounts receivable	34,499	30,198
Fair value of derivatives	6,889	27,850
Other current assets	1,525	1,441
Total current assets	44,941	60,457
Oil and natural gas properties, full-cost accounting method:
Evaluated properties	2,207,999	2,077,985
Less accumulated depreciation, depletion and amortization	(1,514,036)	(1,478,355)
Net oil and natural gas properties	693,963	599,630
Unevaluated properties	131,121	142,525
Total oil and natural gas properties	825,084	742,155
Other property and equipment, net	7,874	7,118
Restricted investments	3,299	3,810
Deferred tax asset	46,497	44,688
Deferred financing costs	16,639	18,200
Other assets, net	658	342
Total assets	944,992	876,770
Current liabilities:
Accounts payable and accrued liabilities	65,792	76,753
Accrued interest	5,974	5,993
Cash-settled restricted stock unit awards	8,172	3,856
Asset retirement obligations	872	4,747
Deferred tax liability	830	6,214
Fair value of derivatives	1,622	1,249
Total current liabilities	83,262	98,812
Senior secured revolving credit facility	75,000	35,000
Secured second lien term loan	300,000	300,000
Asset retirement obligations	3,249	1,927
Cash-settled restricted stock unit awards	3,086	7,175
Other long-term liabilities	219	121
Total liabilities	464,816	443,035
Stockholders' equity:
Preferred stock, series A cumulative, $0.01 par value and $50.00 liquidation preference, 2,500,000 shares authorized: 1,578,948 and 1,578,948 shares outstanding, respectively	16	16
Common stock, $0.01 par value, 110,000,000 shares authorized; 66,190,660 and 55,225,288 shares outstanding, respectively	662	552
Capital in excess of par value	591,604	526,162
Accumulated deficit	(112,106)	(92,995)
Total stockholders' equity	480,176	433,735
Total liabilities and stockholders' equity	$ 944,992	$ 876,770

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Stockholders' equity:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	110,000,000	110,000,000
Common stock, shares outstanding	66,190,660	55,225,288
Series A Preferred Stock [Member]
Stockholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, liquidation preference (in dollars per share)	$ 50	$ 50
Preferred stock, shares authorized	2,500,000	2,500,000
Preferred stock, shares outstanding	1,578,948	1,578,948

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Operating revenues:
Oil sales	$ 36,093	$ 37,710	$ 64,002	$ 68,619
Natural gas sales	3,149	2,792	5,631	5,168
Total operating revenues	39,242	40,502	69,633	73,787
Operating expenses:
Lease operating expenses	6,575	4,363	13,534	8,593
Production taxes	2,952	2,265	5,217	4,182
Depreciation, depletion and amortization	17,587	11,982	35,691	22,520
General and administrative	5,763	9,639	17,865	20,446
Accretion expense	134	173	343	401
Rig termination fee			3,641
Gain on sale of other property and equipment				(1,080)
Total operating expenses	33,011	28,422	76,291	55,062
Income (loss) from operations	6,231	12,080	(6,658)	18,725
Other (income) expenses:
Interest expense	5,106	1,825	9,964	2,802
Gain on early extinguishment of debt		(3,205)		(3,205)
Loss on derivative contracts	8,249	4,685	5,820	7,198
Other income	(41)	(93)	(85)	(142)
Total other expenses	13,314	3,212	15,699	6,653
Income (loss) before income taxes	(7,083)	8,868	(22,357)	12,072
Income tax expense (benefit)	(2,116)	4,128	(7,193)	5,469
Net income (loss)	(4,967)	4,740	(15,164)	6,603
Preferred stock dividends	(1,973)	(1,973)	(3,947)	(3,947)
Income (loss) available to common stockholders	$ (6,940)	$ 2,767	$ (19,111)	$ 2,656
Income (loss) per common share:
Basic	$ (0.11)	$ 0.07	$ (0.31)	$ 0.07
Diluted	$ (0.11)	$ 0.07	$ (0.31)	$ 0.06
Shares used in computing income (loss) per common share:
Basic	66,038	40,606	61,759	40,467
Diluted	66,038	41,605	61,759	41,652

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net income (loss)	$ (15,164)	$ 6,603
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation, depletion and amortization	36,557	22,976
Accretion expense	343	401
Amortization of non-cash debt related items	1,561	298
Amortization of deferred credit		(433)
Deferred income tax (benefit) expense	(7,193)	5,469
Net loss on derivatives, net of settlements	21,129	4,677
Gain on sale of other property and equipment		(1,080)
Non-cash gain on early debt extinguishment		(3,205)
Non-cash expense related to equity share-based awards	(668)	(36)
Change in the fair value of liability share-based awards	4,695	8,070
Payments to settle asset retirement obligations	(1,905)	(1,469)
Changes in current assets and liabilities:
Accounts receivable	(6,946)	(5,268)
Other current assets	(85)	265
Current liabilities	5,549	2,014
Payments to settle vested liability share-based awards related to early retirements	(3,538)	(1,417)
Payments to settle vested liability share-based awards	(3,925)	(2,052)
Change in other long-term liabilities	100
Change in other assets, net	(528)	(216)
Net cash provided by operating activities	29,982	35,597
Cash flows from investing activities:
Capital expenditures	(130,847)	(127,219)
Proceeds from sale of mineral interest and equipment	326	2,267
Net cash used in investing activities	(130,521)	(124,952)
Cash flows from financing activities:
Borrowings on credit facility	103,000	150,000
Payments on credit facility	(63,000)	(55,610)
Payment of deferred financing costs		(2,928)
Issuance of common stock	65,546
Payment of preferred stock dividends	(3,947)	(3,947)
Net cash provided by financing activities	101,599	87,515
Net change in cash and cash equivalents	1,060	(1,840)
Balance, beginning of period	968	3,012
Balance, end of period	$ 2,028	$ 1,172

Description of Business and Bas

Description of Business and Basis of Presentation	6 Months Ended
	Jun. 30, 2015
Description of Business and Basis of Presentation [Abstract]
Description of Business and Basis of Presentation	Note 1 - Description of Business and Basis of Presentation Description of business Callon Petroleum Company is an independent oil and natural gas company established in 1950. The Company was incorporated under the laws of the state of Delaware in 1994 and succeeded to the business of a publicly traded limited partnership, a joint venture with a consortium of European investors and an independent energy company partially owned by a member of current management. As used herein, the “Company,” “Callon,” “we,” “us,” and “our” refer to Callon Petroleum Company and its predecessors and subsidiaries unless the context requires otherwise. Callon is focused on the acquisition, development, exploration and exploitation of unconventional, onshore, oil and natural gas reserves in the Permian Basin in West Texas, and more specifically, the Midland Basin. The Company’s operations to date have been predominantly focused on horizontal drilling of several prospective intervals, including multiple levels of the Wolfcamp formation. Callon has assembled a multi-year inventory of potential horizontal well locations and intends to add to this inventory through delineation drilling of emerging zones on our existing acreage and acquisition of additional locations through acreage purchases, joint ventures and asset swaps. Basis of presentation Unless otherwise indicated, all dollar amounts included within the Footnotes to the Financial Statements are presented in thousands, except for per share and per unit data. The interim consolidated financial statements of the Company have been prepared in accordance with (1) GAAP, (2) the SEC’s instructions to Quarterly Report on Form 10-Q and (3) Rule 10-01 of Regulation S-X, and include the accounts of the Company, and its subsidiary, Callon Petroleum Operating Company (“CPOC”). CPOC also has subsidiaries, namely Callon Offshore Production, Inc. and Mississippi Marketing, Inc. These interim consolidated financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 . The balance sheet at December 31, 2014 has been derived from the audited financial statements at that date. Operating results for the periods presented are not necessarily indicative of the results that may be expected for the year ended December 31, 2015 . In the opinion of management, the accompanying unaudited consolidated financial statements reflect all adjustments, including normal recurring adjustments and all intercompany account and transaction eliminations, necessary to present fairly the Company’s financial position, the results of its operations and its cash flows for the periods indicated. Certain prior year amounts have been reclassified to conform to current year presentation. Recently issued accounting policies In April 2015, the Financial Accounting Standards Board issued accounting standards update (“ASU”) No. 2015-03, Interest – Imputation of Interest: Simplifying the Presentation of Debt Issuance Costs. The standard requires that the costs for issuing debt should appear on the balance sheet as direct reduction from the debt’s value. The guidance in ASU No. 2015-03 is effective for public entities for annual reporting periods beginning after December 15, 2015, including interim periods therein. Early adoption is permitted. The Company is currently evaluating the method of adoption and impact this standard will have on its financial statements and related disclosures.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2015
Acquisitions [Abstract]
Acquisitions	Note 2 – Acquisitions On October 8, 2014, the Company completed the acquisition of certain undeveloped acreage and producing oil and gas properties located in Midland, Andrews, Ector and Martin Counties, Texas (the “Central Midland Basin Acquisition”) for an aggregate cash purchase price of $210,205 . The Company assumed operatorship of the properties on November 1, 2014, and acquired a 62% working interest ( 46.5% net revenue interest) in the Central Midland Basin Acquisition. The aggregate cash purchase price was funded with a combination of the net proceeds from an equity offering of $122,450 and a portion of the net proceeds from borrowings under a secured second lien term loan. The Central Midland Basin Acquisition was accounted for under the acquisition method of accounting, which involves determining the fair value of the assets acquired and liabilities assumed. The following purchase price allocation is based on management’s estimates of the fair value of the assets acquired and liabilities assumed. The following table summarizes the acquisition date fair values of the net assets acquired: Oil and natural gas properties $ Unevaluated oil and natural gas properties Asset retirement obligations Net assets acquired $ The following unaudited summary pro forma financial information for the three and six months ended June 30, 2014 has been presented for illustrative purposes only and does not purport to represent what the Company’s results of operations would have been if the Central Midland Basin Acquisition had occurred as presented, or to project the Company’s results of operations for any future periods. The pro forma financial information was prepared assuming the Central Midland Basin Acquisition occurred as of January 1, 2013. The pro forma adjustments are based on available information and certain assumptions that management believes are reasonable, including revenue, lease operating expenses, production taxes, depreciation, depletion and amortization expense, accretion expense, interest expense and capitalized interest. Three Months Ended Six Months Ended June 30, 2014 June 30, 2014 Revenues $ $ Income from operations Income available to common stockholders Net income per common share: Basic $ $ Diluted $ $

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Earnings Per Share	Note 3 - Earnings Per Share The following table sets forth the computation of basic and diluted earnings per share: (share amounts in thousands) Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Net income (loss) $ $ $ $ Preferred stock dividends Income (loss) available to common stockholders $ $ $ $ Weighted average shares outstanding Dilutive impact of restricted stock — — Weighted average shares outstanding for diluted loss per share Basic income (loss) per share $ $ $ $ Diluted income (loss) per share $ $ $ $ Stock options (a) Restricted stock (a) — — (a) Shares excluded from the diluted earnings per share calculation because their effect would be anti-dilutive.

Borrowings

Borrowings	6 Months Ended
	Jun. 30, 2015
Borrowings [Abstract]
Borrowings	Note 4 – Borrowings The Company’s borrowings consisted of the following at: June 30, 2015 December 31, 2014 Principal components: Senior secured revolving credit facility $ $ Secured second lien term loan Total carrying value of borrowings $ $ Senior secured revolving credit facility (the “Credit Facility”) On March 11, 2014, the Company entered into the Fifth Amended and Restated Credit Agreement to the Credit Facility with a maturity date of March 11, 2019 . JPMorgan Chase Bank, N.A. is Administrative Agent, and participating lenders include Regions Bank, Citibank, N.A., Capital One, N.A., KeyBank, N.A., Whitney Bank, IberiaBank, N.A., OneWest Bank, N.A., SunTrust Bank and Royal Bank of Canada. The total notional amount available under the Credit Facility is $500,000 . Amounts borrowed under the Credit Facility may not exceed the borrowing base, which is generally reviewed on a semi-annual basis. As of June 30, 2015 , the Credit Facility’s borrowing base was $250,000 . The Credit Facility is secured by first preferred mortgages covering the Company’s major producing properties. As of June 30, 2015 , the balance outstanding on the Credit Facility was $75,000 with a weighted-average interest rate of 2.19% , calculated as the LIBOR plus a tiered rate ranging from 1.75% to 2.75% , which is determined based on utilization of the facility. In addition, the Credit Facility carries a commitment fee of 0.5% per annum, payable quarterly, on the unused portion of the borrowing base. Secured second lien term loan (the “Term Loan”) On October 8, 2014, the Company entered into the Term Loan with an aggregate amount of up to $300,000 and a maturity date of October 8, 2021 . The Royal Bank of Canada is Administrative Agent, and participants include several institutional lenders. The Term Loan may be prepaid at the Company’s option, subject to a prepayment premium. The prepayment amount is (i) 102% if the prepayment event occurs prior to October 8, 2015, (ii) 101% if the prepayment event occurs on or after October 8, 2015 but before October 8, 2016, and (iii) 100% for prepayments made on or after October 8, 2016. The Term Loan is secured by junior liens on properties mortgaged under the Credit Facility, subject to an intercreditor agreement. As of June 30, 2015 , the balance outstanding on the Term Loan was $300,000 with an interest rate of 8.5% , calculated at a rate of LIBOR (subject to a floor rate of 1.0% ) plus 7.5% per annum. The Company can elect a LIBOR rate based on various tenors, and is currently incurring interest based on an underlying three-month LIBOR rate, which was last elected in July 2015. Restrictive covenants The Company’s Credit Facility and Term Loan contain various covenants including restrictions on additional indebtedness, payment of cash dividends and maintenance of certain financial ratios. The Company was in compliance with these covenants at June 30, 2015 .

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities [Abstract]
Derivative Instruments and Hedging Activities	Note 5 - Derivative Instruments and Hedging Activities Objectives and strategies for using derivative instruments The Company is exposed to fluctuations in oil and natural gas prices received for its production. Consequently, the Company believes it is prudent to manage the variability in cash flows on a portion of its oil and natural gas production. The Company utilizes a mix of collars, swaps, puts, calls and similar derivative financial instruments to manage fluctuations in cash flows resulting from changes in commodity prices. The Company does not use these instruments for speculative or trading purposes. Counterparty risk and offsetting The use of derivative instruments exposes the Company to the risk that a counterparty will be unable to meet its commitments. While the Company monitors counterparty creditworthiness on an ongoing basis, it cannot predict sudden changes in counterparties’ creditworthiness. In addition, even if such changes are not sudden, the Company may be limited in its ability to mitigate an increase in counterparty credit risk. Should one of these counterparties not perform, the Company may not realize the benefit of some of its derivative instruments under lower commodity prices while continuing to be obligated under higher commodity price contracts subject to any right of offset under the agreements. Counterparty credit risk is considered when determining the fair value of a derivative instrument; see Note 6 for additional information regarding fair value. The Company executes commodity derivative contracts under master agreements that have netting provisions that provide for offsetting assets against liabilities. In general, if a party to a derivative transaction incurs an event of default, as defined in the applicable agreement, the other party will have the right to demand the posting of collateral, demand a cash payment transfer or terminate the arrangement. Financial statement presentation and settlements Settlements of the Company’s derivative instruments are based on the difference between the contract price or prices specified in the derivative instrument and a benchmark price, such as the NYMEX price. To determine the fair value of the Company’s derivative instruments, the Company utilizes present value methods that include assumptions about commodity prices based on those observed in underlying markets. See Note 6 for additional information regarding fair value. Derivatives not designated as hedging instruments The Company records its derivative contracts at fair value in the consolidated balance sheet and records changes in fair value as a gain or loss on derivative contracts in the consolidated statement of operations. Cash settlements are also recorded as gain or loss on derivative contracts in the consolidated statement of operations. The following table reflects the fair value of the Company’s derivative instruments for the periods presented: Balance Sheet Presentation Asset Fair Value Liability Fair Value Net Derivative Fair Value Commodity Classification Line Description 06/30/2015 12/31/2014 06/30/2015 12/31/2014 06/30/2015 12/31/2014 Natural gas Current Fair value of derivatives $ $ $ $ $ $ Oil Current Fair value of derivatives Oil Non-current Other assets, net — — — — Totals $ $ $ $ $ $ As previously discussed, the Company’s derivative contracts are subject to master netting arrangements. The Company’s policy is to present the fair value of derivative contracts on a net basis in the consolidated balance sheet. The following presents the impact of this presentation to the Company’s recognized assets and liabilities for the periods indicated: June 30, 2015 Presented without As Presented with Effects of Netting Effects of Netting Effects of Netting Current assets: Fair value of derivatives $ $ $ Long-term assets: Other assets, net — Current liabilities: Fair value of derivatives $ $ $ December 31, 2014 Presented without As Presented with Effects of Netting Effects of Netting Effects of Netting Current assets: Fair value of derivatives $ $ — $ Current liabilities: Fair value of derivatives $ $ — $ For the periods indicated, the Company recorded the following related to its derivatives in the consolidated statement of operations as gain or loss on derivative contracts: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Oil derivatives Net gain (loss) on settlements $ $ $ $ Net loss on fair value adjustments Total loss $ $ $ $ Natural gas derivatives Net gain (loss) on settlements $ $ $ $ Net gain (loss) on fair value adjustments Total gain (loss) $ $ $ $ Total loss on derivative contracts $ $ $ $ Derivative positions Listed in the tables below are the outstanding oil and natural gas derivative contracts as of June 30, 2015 : For the Three Months Ended September 30, December 31, March 31, June 30, September 30, December 31, Oil contracts 2015 2015 2016 2016 2016 2016 Swap contracts (NYMEX): Total volume (MBbls) Weighted average price per Bbl $ $ $ $ $ $ Swap contracts (Midland basis differential): Volume (MBbls) — — — — Weighted average price per Bbl $ $ $ — $ — $ — $ — Collar contracts combined with short puts (three-way collar): Volume (MBbls) — — Weighted average price per Bbl Ceiling (short call) $ — $ — $ $ $ $ Floor (long put) $ — $ — $ $ $ $ Short put $ — $ — $ $ $ $ For the Three Months Ended September 30, December 31, March 31, June 30, September 30, December 31, Natural gas contracts 2015 2015 2016 2016 2016 2016 Collar contracts combined with short puts (three-way collar): Volume (BBtu) — — — — Weighted average price per MMBtu Ceiling (short call) $ $ $ — $ — $ — $ — Floor (long put) $ $ $ — $ — $ — $ — Short put $ $ $ — $ — $ — $ — Swap contracts: Total volume (BBtu) — — — — Weighted average price per MMBtu $ $ $ — $ — $ — $ — Short call contracts: Short call volume (BBtu) — — — — Short call price per MMBtu $ $ $ — $ — $ — $ —

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2015
Fair Value Measurements [Abstract]
Fair Value Measurements	Note 6 - Fair Value Measurements The fair value hierarchy included in GAAP gives the highest priority to Level 1 inputs, which consist of unadjusted quoted prices for identical instruments in active markets. Level 2 inputs consist of quoted prices for similar instruments. Level 3 valuations are derived from inputs that are significant and unobservable, and these valuations have the lowest priority. Fair Value of Financial Instruments Cash, cash equivalents, restricted investments. The carrying amounts for these instruments approximate fair value due to the short-term nature or maturity of the instruments. Debt. The Company’s debt is recorded at the carrying amount in the consolidated balance sheet. The carrying amount of floating-rate debt approximated fair value because the interest rates were variable and reflective of market rates. Assets and liabilities measured at fair value on a recurring basis Certain assets and liabilities are reported at fair value on a recurring basis in the consolidated balance sheet. The following methods and assumptions were used to estimate fair value: Commodity derivative instruments. The fair value of commodity derivative instruments is derived using an income approach valuation model that utilizes market-corroborated inputs that are observable over the term of the derivative contract. The Company’s fair value calculations also incorporate an estimate of the counterparties’ default risk for derivative assets and an estimate of the Company’s default risk for derivative liabilities. The Company believes that the majority of the inputs used to calculate the commodity derivative instruments fall within Level 2 of the fair-value hierarchy based on the wide availability of quoted market prices for similar commodity derivative contracts. See Note 5 for additional information regarding the Company’s derivative instruments. The following tables present the Company’s assets and liabilities measured at fair value on a recurring basis : Balance Sheet Presentation as of June 30, 2015 Classification Level 1 Level 2 Level 3 Total Fair value of derivatives Current assets $ — $ $ — $ Other assets, net Long-term assets — — Fair value of derivatives Current liabilities — — Total net assets $ — $ $ — $ Balance Sheet Presentation as of December 31, 2014 Classification Level 1 Level 2 Level 3 Total Fair value of derivatives Current assets $ — $ $ — $ Fair value of derivatives Current liabilities — — Total net assets $ — $ $ — $

Asset Retirement Obligations

Asset Retirement Obligations	6 Months Ended
	Jun. 30, 2015
Asset Retirement Obligations [Abstract]
Asset Retirement Obligations	Note 7 - Asset Retirement Obligations The table below summarizes the Company’s asset retirement obligations activity for the six months ended June 30, 2015 : Asset retirement obligations at January 1, 2015 $ Accretion expense Liabilities incurred Liabilities settled Revisions to estimate Asset retirement obligations at end of period Less: Current asset retirement obligations Long-term asset retirement obligations at June 30, 2015 $ Certain of the Company’s operating agreements require that assets be restricted for abandonment obligations. Amounts recorded in the consolidated balance sheets at June 30, 2015 as long-term restricted investments were $3,299 . These assets, which primarily include short-term U.S. Government securities, are held in abandonment trusts dedicated to pay future abandonment costs for several of the Company’s oil and natural gas properties.

Equity Transactions

Equity Transactions	6 Months Ended
	Jun. 30, 2015
Equity Transactions [Abstract]
Equity Transactions	Note 8 – Equity Transactions 10% Series A Cumulative Preferred Stock (“Preferred Stock”) Holders of the Company’s Preferred Stock are entitled to receive, when, as and if declared by our Board of Directors, out of funds legally available for the payment of dividends, cumulative cash dividends at a rate of 10.0% per annum of the $50.00 liquidation preference per share (equivalent to $5.00 per annum per share). Dividends are payable quarterly in arrears on the last day of each March, June, September and December when, as and if declared by our Board of Directors. Preferred Stock dividends were $1,973 and $3,947 for the three and six months ended June 30, 2015 and 2014 , respectively. The Preferred Stock has no stated maturity and is not be subject to any sinking fund or other mandatory redemption. On or after May 30, 2018, the Company may, at its option, redeem the Preferred Stock, in whole or in part, by paying $50.00 per share in cash, plus any accrued and unpaid dividends to the redemption date. Following a change of control, as defined in the prospectus supplement, the Company will have the option to redeem the Preferred Stock, in whole but not in part for $50.00 per share in cash, plus accrued and unpaid dividends (whether or not declared), to the redemption date. If the Company does not exercise its option to redeem the Preferred Stock upon a change of control, the holders of the Preferred Stock have the option to convert the Preferred Stock into a number of shares of the Company’s common stock based on the value of the common stock on the date of the change of control as determined under the certificate of designations for the Preferred Stock. If the change of control occurred on June 30, 2015 , and the Company did not exercise its right to redeem the Preferred Stock, using the closing price of $ 8.32 as the value of a share of common stock, each share of Preferred Stock would be convertible into approximately 6.0 shares of common stock. If the Company exercises its redemption rights relating to shares of Preferred Stock, the holders of Preferred Stock will not have the conversion right described above. Common Stock On March 13, 2015, the Company completed an underwritten public offering of 9,000,000 shares of its common stock at $6.55 per share, before underwriting discounts, and the exercise in full by the underwriters of their option to purchase 1,350,000 additional shares of common stock at $6.55 per share, before underwriting discounts. The Company received net proceeds of approximately $65,546 , after the underwriting discounts and estimated offering costs.

Other

Other	6 Months Ended
	Jun. 30, 2015
Other [Abstract]
Other	Note 9 – Other Operating leases As of June 30, 2015 , the Company had contracts for two horizontal drilling rigs (the “Cactus 1 Rig” and “Cactus 2 Rig”). The Cactus 1 Rig was initially contracted for a term of two years in April 2012. The Cactus 2 Rig was initially contracted for a term of two years in April 2014. The Cactus 2 Rig replaced a previously contracted horizontal drilling rig, which was cancelled in March 2014. In March 2015, the Company extended the terms of its Cactus 1 Rig and Cactus 2 Rig to end in July 2018 and August 2018, respectively. The rig lease agreements include early termination provisions that obligate the Company to reduced minimum rentals pursuant to a “standby” dayrate for the term of the agreement. These payments would be reduced assuming the lessor is able to re-charter the rig and staffing personnel to another l essee. In March 2015, the Company decided to terminate its one-year contract for a vertical rig (effective April 2015) and will be required to pay approximately $3,641 in reduced rental payments over the remainder of the lease term ending November 2015 , unless the lessor is able to re-charter the rig to another lessee. This amount was recognized as rig termination fee on the consolidated statements of operations for the three and six months ended June 30, 2015 . As of June 30, 2015 , the Company had paid $1,392 of the estimated $3,641 in reduced rental payments.

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2015
Acquisitions [Abstract]
Fair Value of Net Assets Acquired	Oil and natural gas properties $ Unevaluated oil and natural gas properties Asset retirement obligations Net assets acquired $
Unaudited Summary Pro Forma Financial Information	Three Months Ended Six Months Ended June 30, 2014 June 30, 2014 Revenues $ $ Income from operations Income available to common stockholders Net income per common share: Basic $ $ Diluted $ $

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Computation of Earnings Per Share, Basic and Diluted	(share amounts in thousands) Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Net income (loss) $ $ $ $ Preferred stock dividends Income (loss) available to common stockholders $ $ $ $ Weighted average shares outstanding Dilutive impact of restricted stock — — Weighted average shares outstanding for diluted loss per share Basic income (loss) per share $ $ $ $ Diluted income (loss) per share $ $ $ $ Stock options (a) Restricted stock (a) — — Shares excluded from the diluted earnings per share calculation because their effect would be anti-dilutive.

Borrowings (Tables)

Borrowings (Tables)	6 Months Ended
	Jun. 30, 2015
Borrowings [Abstract]
Schedule of Borrowings	June 30, 2015 December 31, 2014 Principal components: Senior secured revolving credit facility $ $ Secured second lien term loan Total carrying value of borrowings $ $

Derivative Instruments and He18

Derivative Instruments and Hedging Activities (Tables)	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	Balance Sheet Presentation Asset Fair Value Liability Fair Value Net Derivative Fair Value Commodity Classification Line Description 06/30/2015 12/31/2014 06/30/2015 12/31/2014 06/30/2015 12/31/2014 Natural gas Current Fair value of derivatives $ $ $ $ $ $ Oil Current Fair value of derivatives Oil Non-current Other assets, net — — — — Totals $ $ $ $ $ $ As previously discussed, the Company’s derivative contracts are subject to master netting arrangements. The Company’s policy is to present the fair value of derivative contracts on a net basis in the consolidated balance sheet. The following presents the impact of this presentation to the Company’s recognized assets and liabilities for the periods indicated: June 30, 2015 Presented without As Presented with Effects of Netting Effects of Netting Effects of Netting Current assets: Fair value of derivatives $ $ $ Long-term assets: Other assets, net — Current liabilities: Fair value of derivatives $ $ $ December 31, 2014 Presented without As Presented with Effects of Netting Effects of Netting Effects of Netting Current assets: Fair value of derivatives $ $ — $ Current liabilities: Fair value of derivatives $ $ — $
Schedule of Gain or Loss on Derivative Contracts	Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Oil derivatives Net gain (loss) on settlements $ $ $ $ Net loss on fair value adjustments Total loss $ $ $ $ Natural gas derivatives Net gain (loss) on settlements $ $ $ $ Net gain (loss) on fair value adjustments Total gain (loss) $ $ $ $ Total loss on derivative contracts $ $ $ $
Schedule of Outstanding Oil and Natural Gas Derivative Contracts	For the Three Months Ended September 30, December 31, March 31, June 30, September 30, December 31, Oil contracts 2015 2015 2016 2016 2016 2016 Swap contracts (NYMEX): Total volume (MBbls) Weighted average price per Bbl $ $ $ $ $ $ Swap contracts (Midland basis differential): Volume (MBbls) — — — — Weighted average price per Bbl $ $ $ — $ — $ — $ — Collar contracts combined with short puts (three-way collar): Volume (MBbls) — — Weighted average price per Bbl Ceiling (short call) $ — $ — $ $ $ $ Floor (long put) $ — $ — $ $ $ $ Short put $ — $ — $ $ $ $ For the Three Months Ended September 30, December 31, March 31, June 30, September 30, December 31, Natural gas contracts 2015 2015 2016 2016 2016 2016 Collar contracts combined with short puts (three-way collar): Volume (BBtu) — — — — Weighted average price per MMBtu Ceiling (short call) $ $ $ — $ — $ — $ — Floor (long put) $ $ $ — $ — $ — $ — Short put $ $ $ — $ — $ — $ — Swap contracts: Total volume (BBtu) — — — — Weighted average price per MMBtu $ $ $ — $ — $ — $ — Short call contracts: Short call volume (BBtu) — — — — Short call price per MMBtu $ $ $ — $ — $ — $ —

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2015
Fair Value Measurements [Abstract]
Fair Value of Assets and Liabilities Measured on Recurring Basis	Balance Sheet Presentation as of June 30, 2015 Classification Level 1 Level 2 Level 3 Total Fair value of derivatives Current assets $ — $ $ — $ Other assets, net Long-term assets — — Fair value of derivatives Current liabilities — — Total net assets $ — $ $ — $ Balance Sheet Presentation as of December 31, 2014 Classification Level 1 Level 2 Level 3 Total Fair value of derivatives Current assets $ — $ $ — $ Fair value of derivatives Current liabilities — — Total net assets $ — $ $ — $

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	6 Months Ended
	Jun. 30, 2015
Asset Retirement Obligations [Abstract]
Schedule of Change in Asset Retirement Obligation	Asset retirement obligations at January 1, 2015 $ Accretion expense Liabilities incurred Liabilities settled Revisions to estimate Asset retirement obligations at end of period Less: Current asset retirement obligations Long-term asset retirement obligations at June 30, 2015 $

Acquistions (Narrative) (Detail

Acquistions (Narrative) (Details) - Oct. 08, 2014 - Central Midland Basin [Member] - USD ($) $ in Thousands	Total
Business Acquisition [Line Items]
Aggregate cash purchase price	$ 210,205
Working interest	62.00%
Net revenue interest	46.50%
Equity offering	$ 122,450

Acquistions (Schedule of Acquis

Acquistions (Schedule of Acquisition Fair Value of Net Assets ) (Details) - Central Midland Basin [Member] $ in Thousands	Oct. 08, 2014USD ($)
Business Acquisition [Line Items]
Oil and natural gas properties	$ 91,895
Asset retirement obligations	(140)
Net assets to be acquired	210,205
Unevaluated Oil and Gas Properties [Member]
Business Acquisition [Line Items]
Oil and natural gas properties	$ 118,450

Acquisitions (Unaudited Pro For

Acquisitions (Unaudited Pro Forma Financial Information) (Details) - Jun. 30, 2014 - Central Midland Basin [Member] - USD ($) $ / shares in Units, $ in Thousands	Total	Total
Business Acquisition [Line Items]
Revenues	$ 50,819	$ 94,003
Income from operations	17,941	30,298
Income available to common stockholders	$ 4,752	$ 5,543
Basic	$ 0.09	$ 0.10
Diluted	$ 0.08	$ 0.10

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share, Basic and Diluted
Net income (loss)	$ (4,967)	$ 4,740	$ (15,164)	$ 6,603
Preferred stock dividends	(1,973)	(1,973)	(3,947)	(3,947)
Income (loss) available to common stockholders	$ (6,940)	$ 2,767	$ (19,111)	$ 2,656
Weighted average shares outstanding	66,038	40,606	61,759	40,467
Weighted average shares outstanding for diluted loss per share	66,038	41,605	61,759	41,652
Basic income (loss) per share	$ (0.11)	$ 0.07	$ (0.31)	$ 0.07
Diluted income (loss) per share	$ (0.11)	$ 0.07	$ (0.31)	$ 0.06
Stock options [Member]
Earnings Per Share, Basic and Diluted
Excluded from the diluted EPS calculation because their effect would be anti-dilutive	15	30	15	30
Restricted Stock [Member]
Earnings Per Share, Basic and Diluted
Dilutive impact		999		1,185
Excluded from the diluted EPS calculation because their effect would be anti-dilutive	284		284

Borrowings (Schedule of Borrowi

Borrowings (Schedule of Borrowings) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Principal components:
Senior secured revolving credit facility	$ 75,000	$ 35,000
Principal components:
Total carrying value of borrowings	375,000	335,000
Senior Secured Revolving Credit Facility [Member]
Principal components:
Senior secured revolving credit facility	75,000	35,000
Secured second lien term loan [Member]
Principal components:
Term loan	$ 300,000	$ 300,000

Borrowings (Senior secured revo

Borrowings (Senior secured revolving credit facility ) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Line of Credit Facility [Line Items]
Senior secured revolving credit facility	$ 75,000	$ 35,000
Senior Secured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	500,000
Current borrowing capacity	250,000
Senior secured revolving credit facility	$ 75,000	$ 35,000
Interest rate at period end (as a percent)	2.19%
Unused capacity, commitment fee (as a percent)	0.50%
Debt Instrument, Maturity Date	Mar. 11, 2019
Senior Secured Revolving Credit Facility [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Basis Spread on LIBOR (as a percent)	1.75%
Senior Secured Revolving Credit Facility [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Basis Spread on LIBOR (as a percent)	2.75%

Borrowings (Term Loans) (Detail

Borrowings (Term Loans) (Details) - Secured second lien term loan [Member] - Range [Domain] - USD ($) $ in Thousands	Oct. 08, 2014	Jun. 30, 2015	Dec. 31, 2014
Line of Credit Facility [Line Items]
Long-term debt, gross		$ 300,000	$ 300,000
Proceeds from Issuance of Debt	$ 300,000
Debt Instrument, Interest Rate, Effective Percentage		8.50%
Floor rate		1.00%
Basis Spread on LIBOR (as a percent)		7.50%
Debt Instrument, Maturity Date		Oct. 8, 2021
Prior to First Anniversary [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Prepayment Premium Percentage	102.00%
After First Anniversary but Prior to Second Anniversary [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Prepayment Premium Percentage	101.00%
After Second Anniversary [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Prepayment Premium Percentage	100.00%

Derivative Instruments and He28

Derivative Instruments and Hedging Activities (Derivatives Fair Value by Balance Sheet Location) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Net Derivative Fair Value	$ 5,472	$ 26,601
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Fair Value	7,094	27,850
Liability Fair Value	(1,622)	(1,249)
Net Derivative Fair Value	5,472	26,601
Current assets - Fair market value of derivatives [Member] | Not Designated as Hedging Instrument [Member] | Crude Oil [Member]
Derivatives, Fair Value [Line Items]
Asset Fair Value	6,218	26,588
Current assets - Fair market value of derivatives [Member] | Not Designated as Hedging Instrument [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Asset Fair Value	671	1,262
Current liabilities - Fair market value of derivatives [Member] | Not Designated as Hedging Instrument [Member] | Crude Oil [Member]
Derivatives, Fair Value [Line Items]
Liability Fair Value	(1,621)	(1,242)
Current liabilities - Fair market value of derivatives [Member] | Not Designated as Hedging Instrument [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Liability Fair Value	(1)	(7)
Non-current assets - Other long-term assets [Member] | Not Designated as Hedging Instrument [Member] | Crude Oil [Member]
Derivatives, Fair Value [Line Items]
Asset Fair Value	205
Balance Sheet Current [Member] | Not Designated as Hedging Instrument [Member] | Crude Oil [Member]
Derivatives, Fair Value [Line Items]
Net Derivative Fair Value	4,597	25,346
Balance Sheet Current [Member] | Not Designated as Hedging Instrument [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Net Derivative Fair Value	670	$ 1,255
Balance Sheet Non Current [Member] | Not Designated as Hedging Instrument [Member] | Crude Oil [Member]
Derivatives, Fair Value [Line Items]
Net Derivative Fair Value	$ 205

Derivative Instruments and He29

Derivative Instruments and Hedging Activities (Derivative Netting Adjustments) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets: Fair value of hedging contracts [Member]
Offsetting Assets and Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 8,370	$ 27,850
Derivative Asset, Fair Value, Gross Liability	(1,481)
Derivative Assets	6,889	27,850
Long-term assets: Fair value of hedging contracts [Member]
Offsetting Assets and Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	205
Derivative Assets	205
Current liabilities: Fair value of hedging contracts [Member]
Offsetting Assets and Liabilities [Line Items]
Derivative Liability, Fair Value, Gross Liability	(3,103)	(1,249)
Derivative Liability, Fair Value, Gross Asset	1,481
Derivative Liabilities	$ (1,622)	$ (1,249)

Derivative Instruments and He30

Derivative Instruments and Hedging Activities (Gain or loss on derivative contracts) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Net gain (loss) on fair value adjustments			$ (21,129)	$ (4,677)
Total gain (loss) on derivative instruments	$ (8,249)	$ (4,685)	(5,820)	(7,198)
Crude Oil [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gain (loss) on settlements	4,511	(1,569)	14,464	(2,341)
Net gain (loss) on fair value adjustments	(12,755)	(3,097)	(20,544)	(4,546)
Total gain (loss) on derivative instruments	(8,244)	(4,666)	(6,080)	(6,887)
Natural Gas [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gain (loss) on settlements	454	(77)	845	(179)
Net gain (loss) on fair value adjustments	(459)	58	(585)	(132)
Total gain (loss) on derivative instruments	$ (5)	$ (19)	$ 260	$ (311)

Derivative Instruments and He31

Derivative Instruments and Hedging Activities (Derivative Positions) (Details) - Jun. 30, 2015 - Not Designated as Hedging Instrument [Member] MMBTU in Thousands	MMBTU$ / bbl$ / MMBTUMBbls
Collar Contracts Combined With Short Puts Three Months Ended September 30, 2015 [Member] | Natural Gas [Member]
Derivative [Line Items]
Total volume | MMBTU	207
Collar Contracts Combined With Short Puts Three Months Ended September 30, 2015 [Member] | Natural Gas [Member] | Call Option [Member] | Short [Member]
Derivative [Line Items]
Strike price | $ / MMBTU	4.32
Collar Contracts Combined With Short Puts Three Months Ended September 30, 2015 [Member] | Natural Gas [Member] | Put Option [Member] | Long [Member]
Derivative [Line Items]
Strike price | $ / MMBTU	3.85
Collar Contracts Combined With Short Puts Three Months Ended September 30, 2015 [Member] | Natural Gas [Member] | Put Option [Member] | Short [Member]
Derivative [Line Items]
Strike price | $ / MMBTU	3.25
Collar Contracts Combined With Short Puts Three Months Ended December 31, 2015 [Member] | Natural Gas [Member]
Derivative [Line Items]
Total volume | MMBTU	161
Collar Contracts Combined With Short Puts Three Months Ended December 31, 2015 [Member] | Natural Gas [Member] | Call Option [Member] | Short [Member]
Derivative [Line Items]
Strike price | $ / MMBTU	4.32
Collar Contracts Combined With Short Puts Three Months Ended December 31, 2015 [Member] | Natural Gas [Member] | Put Option [Member] | Long [Member]
Derivative [Line Items]
Strike price | $ / MMBTU	3.85
Collar Contracts Combined With Short Puts Three Months Ended December 31, 2015 [Member] | Natural Gas [Member] | Put Option [Member] | Short [Member]
Derivative [Line Items]
Strike price | $ / MMBTU	3.25
Collar Contracts Combined With Short Puts Three Months Ended March 31, 2016 [Member] | Crude Oil [Member]
Derivative [Line Items]
Total volume | MBbls	91
Collar Contracts Combined With Short Puts Three Months Ended March 31, 2016 [Member] | Crude Oil [Member] | Call Option [Member] | Short [Member]
Derivative [Line Items]
Strike price	70
Collar Contracts Combined With Short Puts Three Months Ended March 31, 2016 [Member] | Crude Oil [Member] | Put Option [Member] | Long [Member]
Derivative [Line Items]
Strike price	60
Collar Contracts Combined With Short Puts Three Months Ended March 31, 2016 [Member] | Crude Oil [Member] | Put Option [Member] | Short [Member]
Derivative [Line Items]
Strike price	45
Collar Contracts Combined With Short Puts Three Months Ended June 30, 2016 [Member] | Crude Oil [Member]
Derivative [Line Items]
Total volume | MBbls	91
Collar Contracts Combined With Short Puts Three Months Ended June 30, 2016 [Member] | Crude Oil [Member] | Call Option [Member] | Short [Member]
Derivative [Line Items]
Strike price	70
Collar Contracts Combined With Short Puts Three Months Ended June 30, 2016 [Member] | Crude Oil [Member] | Put Option [Member] | Long [Member]
Derivative [Line Items]
Strike price	60
Collar Contracts Combined With Short Puts Three Months Ended June 30, 2016 [Member] | Crude Oil [Member] | Put Option [Member] | Short [Member]
Derivative [Line Items]
Strike price	45
Collar Contracts Combined With Short Puts Three Months Ended September 30, 2016 [Member] | Crude Oil [Member]
Derivative [Line Items]
Total volume | MBbls	92
Collar Contracts Combined With Short Puts Three Months Ended September 30, 2016 [Member] | Crude Oil [Member] | Call Option [Member] | Short [Member]
Derivative [Line Items]
Strike price	70
Collar Contracts Combined With Short Puts Three Months Ended September 30, 2016 [Member] | Crude Oil [Member] | Put Option [Member] | Long [Member]
Derivative [Line Items]
Strike price	60
Collar Contracts Combined With Short Puts Three Months Ended September 30, 2016 [Member] | Crude Oil [Member] | Put Option [Member] | Short [Member]
Derivative [Line Items]
Strike price	45
Collar Contracts Combined With Short Puts Three Months Ended December 31, 2016 [Member] | Crude Oil [Member]
Derivative [Line Items]
Total volume | MBbls	92
Collar Contracts Combined With Short Puts Three Months Ended December 31, 2016 [Member] | Crude Oil [Member] | Call Option [Member] | Short [Member]
Derivative [Line Items]
Strike price	70
Collar Contracts Combined With Short Puts Three Months Ended December 31, 2016 [Member] | Crude Oil [Member] | Put Option [Member] | Long [Member]
Derivative [Line Items]
Strike price	60
Collar Contracts Combined With Short Puts Three Months Ended December 31, 2016 [Member] | Crude Oil [Member] | Put Option [Member] | Short [Member]
Derivative [Line Items]
Strike price	45
Swap Contracts Three Months Ended September 30, 2015 [Member] | Crude Oil [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MBbls	520
Average swap price	67.22
Swap Contracts Three Months Ended September 30, 2015 [Member] | Natural Gas [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MMBTU	219
Average swap price | $ / MMBTU	3.98
Swap Contracts Three Months Ended December 31, 2015 [Member] | Crude Oil [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MBbls	442
Average swap price	64.93
Swap Contracts Three Months Ended December 31, 2015 [Member] | Natural Gas [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MMBTU	228
Average swap price | $ / MMBTU	3.96
Swap Contracts Three Months Ended March 31, 2016 [Member] | Crude Oil [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MBbls	91
Average swap price	63.50
Swap Contracts Three Months Ended June 30, 2016 [Member] | Crude Oil [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MBbls	91
Average swap price	63.50
Swap Contracts Three Months Ended September 30, 2016 [Member] | Crude Oil [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MBbls	92
Average swap price	63.50
Swap Contracts Three Months Ended December 31, 2016 [Member] | Crude Oil [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MBbls	92
Average swap price	63.50
Swap Contracts Differentials Three Months Ended September 30, 2015 [Member] | Crude Oil [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MBbls	382
Average swap price	(2.39)
Swap Contracts Differentials Three Months Ended December 31, 2015 [Member] | Crude Oil [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MBbls	327
Average swap price	(2.38)
Short Call Contracts Three Months September 30, 2015 [Member] | Natural Gas [Member] | Call Option [Member] | Short [Member]
Derivative [Line Items]
Total volume | MMBTU	110
Strike price | $ / MMBTU	5
Short Call Contracts Three Months December 31, 2015 [Member] | Natural Gas [Member] | Call Option [Member] | Short [Member]
Derivative [Line Items]
Total volume | MMBTU	111
Strike price | $ / MMBTU	5

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value of Assets and Liabilities Measured on Recurring Basis) (Details) - Balance Sheet Location [Domain] - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Derivative Assets
Derivative Assets, Current	$ 6,889	$ 27,850
Derivative Assets, Noncurrent	205
Derivative Liabilities
Derivative Liabilities, Current	(1,622)	(1,249)
Fair Value, Net Asset	5,472	26,601
Level 2 [Member]
Derivative Assets
Derivative Assets, Current	6,889	27,850
Derivative Assets, Noncurrent	205
Derivative Liabilities
Derivative Liabilities, Current	(1,622)	(1,249)
Fair Value, Net Asset	$ 5,472	$ 26,601

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations at beginning of the period			$ 6,674
Accretion expense	$ 134	$ 173	343	$ 401
Liabilities incurred			88
Liabilities settled			(2,533)
Revisions to estimate			(451)
Asset retirement obligations at end of period	4,121		$ 6,674		$ 6,674
Less: current asset retirement obligations	(872)				(4,747)
Long-term asset retirement obligations at the end of the period	3,249				1,927
Restricted Investments
Restricted investments	$ 3,299				$ 3,810

Equity Transactions (Details)

Equity Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 13, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Class of Stock [Line Items]
Preferred stock redemption, description				The Preferred Stock has no stated maturity and is not be subject to any sinking fund or other mandatory redemption. On or after May 30, 2018, the Company may, at its option, redeem the Preferred Stock, in whole or in part, by paying $50.00 per share in cash, plus any accrued and unpaid dividends to the redemption date.
Preferred stock, dividend expense		$ 1,973	$ 1,973	$ 3,947	$ 3,947
Share Price		$ 8.32		$ 8.32
Conversion ratio of preferred stock to common stock				6
Stock issued during period (in shares)	9,000,000
Shares price issued	$ 6.55
Proceeds from issuance of common stock	$ 65,546			$ 65,546
Over-Allotment Option [Member]
Class of Stock [Line Items]
Stock issued during period (in shares)	1,350,000
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Dividend Rate, Percentage				10.00%
Preferred stock, liquidation preference (in dollars per share)		50		$ 50		$ 50
Preferred Stock, Dividend Rate, Per-Dollar-Amount, Per Annum				5
Preferred stock, redemption price per share		$ 50		$ 50
Preferred stock, dividend expense		$ 1,973	$ 1,973	$ 3,947	$ 3,947

Other (Narrative) (Details)

Other (Narrative) (Details) - Jun. 30, 2015 $ in Thousands	USD ($)contract
Operating Leases And Other Property Plant And Equipment [Line Items]
Early rig contract termination payable	$ 3,641
Amount paid for early termination	$ 1,392
Horizontal Drilling [Member]
Operating Leases And Other Property Plant And Equipment [Line Items]
Number of Contracts | contract	2
Extended contract expiration terms	The Cactus 1 Rig was initially contracted for a term of two years in April 2012. The Cactus 2 Rig was initially contracted for a term of two years in April 2014. The Cactus 2 Rig replaced a previously contracted horizontal drilling rig, which was cancelled in March 2014. In March 2015, the Company extended the terms of its Cactus 1 Rig and Cactus 2 Rig to end in July 2018 and August 2018, respectively.
Operating leases, term of contract	2 years