Miller Energy Resources (MILL) 10-Q 10 Dec 14 2015 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Oct. 31, 2014	Nov. 24, 2014
DOCUMENT AND ENTITY INFORMATION	'	'
Entity Registrant Name	'MILLER ENERGY RESOURCES, INC.	'
Entity Central Index Key	'0000785968	'
Current Fiscal Year End Date	'--04-30	'
Entity Filer Category	'Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Oct-14	'
Document Fiscal Year Focus	'2015	'
Document Fiscal Period Focus	'Q2	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	46,634,471

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Oct. 31, 2014	Apr. 30, 2014
In Thousands, unless otherwise specified
CURRENT ASSETS:	'	'
Cash and cash equivalents	$14,484	$5,749
Restricted cash	1,147	679
Accounts receivable, net of allowances of $303 and $252	8,228	6,409
Alaska production credits receivable, net of allowances of $4,187 and $7,124	37,684	49,121
Inventory	7,778	5,102
Prepaid expenses and other	5,978	3,852
Short-term portion of derivative instruments	7,222	88
Deferred income taxes	2,666	'
Assets held for sale	5,308	236
Total current assets	90,495	71,236
OIL AND GAS PROPERTIES, NET	362,555	644,827
EQUIPMENT, NET	54,230	35,369
OTHER ASSETS:	'	'
Land	1,848	1,848
Restricted cash, non-current	14,364	12,075
Deferred financing costs, net	2,385	803
Long-term portion of derivative instruments	2,159	26
Other assets	783	638
Total assets	528,819	766,822
CURRENT LIABILITIES:	'	'
Accounts payable	47,252	38,836
Accrued expenses	18,749	20,446
Short-term portion of derivative instruments	'	3,315
Deferred income taxes	'	2,858
Current portion of long-term debt and capital leases	24,672	9,459
Liabilities held for sale	1,495	0
Total current liabilities	92,168	74,914
OTHER LIABILITIES:	'	'
Deferred income taxes	20,197	139,768
Asset retirement obligation	22,276	22,872
Long-term portion of derivative instruments	'	4,006
Long-term debt and capital leases, less current portion	194,346	174,743
Other	29	'
Total liabilities	329,016	416,303
MEZZANINE EQUITY:	'	'
Series C Cumulative Preferred Stock, redemption amount of $78,124, 3,250,000 shares authorized, 3,069,968 shares issued and outstanding as of October 31, 2014 and April 30, 2014	69,154	67,760
STOCKHOLDERS' EQUITY:	'	'
Series D Cumulative Redeemable Preferred Stock, redemption amount of $53,276 and $32,378, 4,000,000 shares authorized, 2,112,458 and 1,070,448 shares issued and outstanding as of October 31, 2014 and April 30, 2014, respectively	49,791	30,041
Series D Cumulative Redeemable Preferred Stock, 0 and 213,586 shares held in escrow as of October 31, 2014 and April 30, 2014, respectively	'	5,000
Common stock, $0.0001 par, 500,000,000 shares authorized, 46,599,471 and 45,756,697 shares issued and outstanding as of October 31, 2014 and April 30, 2014, respectively	5	4
Additional paid-in capital	109,829	98,788
Retained earnings (accumulated deficit)	-28,976	158,926
Total stockholders' equity	130,649	282,759
Total liabilities and stockholders' equity	$528,819	$766,822

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Oct. 31, 2014	Apr. 30, 2014
Allowance for accounts receivable	$303,000	$252,000
Allowances for Alaska production credits receivable	4,187,000	7,124,000
Common Stock	'	'
Par value (in dollars per share)	$0.00	$0.00
Shares authorized (in shares)	500,000,000	500,000,000
Shares issued (in shares)	46,599,471	45,756,697
Shares outstanding (in shares)	46,599,471	45,756,697
Series C Preferred Stock [Member]	'	'
Preferred Stock	'	'
Series C redemption amount	78,124,000	78,124,000
Shares authorized (in shares)	3,250,000	3,250,000
Shares issued (in shares)	3,069,968	3,069,968
Shares outstanding (in shares)	3,069,968	3,069,968
Series D Preferred Stock [Member]	'	'
Preferred Stock	'	'
Series D redemption amount	$53,276,000	$32,378,000
Shares authorized (in shares)	4,000,000	4,000,000
Shares issued (in shares)	2,112,458	1,070,448
Shares outstanding (in shares)	2,112,458	1,070,448
Shares held In escrow (in shares)	'	213,586

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
REVENUES:	'	'	'	'
Oil sales	$18,044	$18,406	$37,345	$30,664
Natural gas sales	5,865	283	11,662	553
Other	267	107	548	587
Total revenues	24,176	18,796	49,555	31,804
OPERATING EXPENSES:	'	'	'	'
Lease operating expense	8,963	5,176	15,589	10,816
Transportation costs	-442	987	2,542	1,612
Cost of purchased gas sold	1,284	'	2,256	'
Cost of other revenue	325	304	665	588
General and administrative	17,901	7,145	27,412	13,505
Alaska carried-forward annual loss credits, net	323	'	-2,732	'
Exploration expense	166,812	148	167,108	434
Depreciation, depletion and amortization	20,082	9,018	37,060	14,710
Accretion of asset retirement obligation	351	301	697	598
Impairment of proved properties	113,734	'	113,734	'
Other operating expense, net	'	'	4	'
Total operating expense	329,333	23,079	364,335	42,263
OPERATING LOSS	-305,157	-4,283	-314,780	-10,459
OTHER INCOME (EXPENSE):	'	'	'	'
Interest expense, net	-3,619	-1,363	-6,418	-3,644
Gain (loss) on derivatives, net	23,089	-4,190	16,186	-7,266
Other income (expense), net	33	-2	155	-16
Total other income (expense)	19,503	-5,555	9,923	-10,926
LOSS BEFORE INCOME TAXES	-285,654	-9,838	-304,857	-21,385
Income tax benefit	117,746	4,850	125,095	9,469
NET LOSS	-167,908	-4,988	-179,762	-11,916
Accretion of Series C and D preferred stock	-913	-665	-1,734	-1,118
Series C and D preferred stock cumulative dividends	-3,459	-2,632	-6,406	-4,668
NET LOSS ATTRIBUTABLE TO COMMON STOCKHOLDERS	($172,280)	($8,285)	($187,902)	($17,702)
LOSS PER COMMON SHARE:	'	'	'	'
Basic (in dollars per share)	($3.71)	($0.19)	($4.07)	($0.40)
Diluted (in dollars per share)	($3.71)	($0.19)	($4.07)	($0.40)
WEIGHTED AVERAGE NUMBER OF COMMON SHARES:	'	'	'	'
Basic (in shares)	46,367,131	44,081,775	46,147,038	43,768,414
Diluted (in shares)	46,367,131	44,081,775	46,147,038	43,768,414

Condensed_Consolidated_Stateme1

Condensed Consolidated Statement of Stockholders' Equity (USD $)	Total	Series C Preferred Stock [Member]	Series D Preferred Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Retained Earnings (Accumulated Deficit) [Member]	Retained Earnings (Accumulated Deficit) [Member]
In Thousands, except Share data, unless otherwise specified				Series D Preferred Stock [Member]				Series C Preferred Stock [Member]	Series D Preferred Stock [Member]
Balance at April 30, 2014 at Apr. 30, 2014	$282,759	'	'	$25,041	$4	$98,788	$158,926	'	'
Balance at April 30, 2014 (in shares) at Apr. 30, 2014	'	'	'	1,070,448	45,756,697	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'	'
Net loss	-179,762	'	'	'	'	'	-179,762	'	'
Series C preferred stock dividends	'	-4,126	'	'	'	'	'	-4,126	'
Accretion of Series C preferred stock	'	-1,394	'	'	'	'	'	-1,394	'
Issuance of Series D preferred stock	'	'	24,410	24,410	'	'	'	'	'
Issuance of Series D preferred stock (in shares)	'	'	'	1,042,010	'	'	'	'	'
Series D preferred stock dividends	'	'	-2,280	'	'	'	'	'	-2,280
Accretion of Series D preferred stock	'	'	0	340	'	'	'	'	-340
Issuance of equity for services	574	'	'	'	'	574	'	'	'
Issuance of equity for compensation	9,059	'	'	'	'	9,059	'	'	'
Issuance of equity for compensation (in shares)	'	'	'	'	521,420	'	'	'	'
Exercise of equity rights	1,409	'	'	'	1	1,408	'	'	'
Exercise of equity rights (in shares)	321,354	'	'	'	321,354	'	'	'	'
Balance at October 31, 2014 at Oct. 31, 2014	$130,649	'	'	$49,791	$5	$109,829	($28,976)	'	'
Balance at October 31, 2014 (in shares) at Oct. 31, 2014	'	'	'	2,112,458	46,599,471	'	'	'	'

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
Net loss	($179,762)	($11,916)
Adjustments to reconcile net loss to net cash provided by operating activities:	'	'
Depreciation, depletion and amortization	37,060	14,710
Amortization of deferred financing fees and debt discount	799	754
Expense from issuance of equity	10,113	3,574
Non-cash exploration expenses	166,303	193
Impairment of proved properties	113,734	'
Deferred income taxes	-125,095	-9,556
Derivative contracts:	'	'
(Gain) loss on derivatives, net	-16,186	7,266
Cash settlements paid	-402	-1,782
Alaska carried-forward annual loss credits, net	-2,732	'
Accretion of asset retirement obligation	697	598
Other, net	309	930
Changes in operating assets and liabilities (excluding effects of acquisitions):	'	'
Receivables	17,883	383
Inventory	28	1,487
Prepaid expenses and other assets	817	-1,420
Accounts payable, accrued expenses and other	1,917	-1,047
NET CASH PROVIDED BY OPERATING ACTIVITIES	25,483	4,174
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Capital expenditures for oil and gas properties	-78,215	-66,171
Proceeds from Alaska expenditure and exploration based credits	36,809	9,668
Prepayment of drilling costs	'	-2,192
Deposits for potential acquisition	-3,000	'
Purchase of equipment and improvements	-16,359	-950
NET CASH USED IN INVESTING ACTIVITIES	-60,765	-59,645
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'
Cash dividends	-5,863	-3,258
Payments on debt	-14,611	'
Proceeds from borrowings	46,000	20,000
Proceeds from capital lease obligations	3,250	'
Principal payments on capital lease obligations	-299	'
Debt acquisition costs	-2,076	-1,900
Issuance of preferred stock	20,376	56,333
Equity issuance costs	-1,412	-3,683
Exercise of equity rights	1,409	2,283
Restricted cash	-2,757	5,027
Other	'	3
NET CASH PROVIDED BY FINANCING ACTIVITIES	44,017	74,805
NET CHANGE IN CASH AND CASH EQUIVALENTS	8,735	19,334
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	5,749	2,551
CASH AND CASH EQUIVALENTS AT END OF PERIOD	14,484	21,885
SUPPLEMENTARY CASH FLOW DATA:	'	'
Cash paid for interest	11,914	5,712
SIGNIFICANT NON-CASH INVESTING AND FINANCING ACTIVITIES:	'	'
Increase in capital expenditures included in accounts payable and accrued expenses	3,951	15,325
Reduction of oil and gas properties and equipment from applications for Alaska expenditure and exploration based credits	41,843	5,642
Accretion of preferred stock	1,734	1,118
Anchor Point Pipeline gathering system	$5,446	$0

Organization_and_Basis_of_Pres

Organization and Basis of Presentation	6 Months Ended
	Oct. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Organization and Basis of Presentation	'
	ORGANIZATION AND BASIS OF PRESENTATION
	Overview
	Unless specifically set forth to the contrary, when used in this report, the terms "Miller Energy Resources," the "Company," "we," "us," "ours," "MER," "Miller," and similar terms refer to our Tennessee corporation Miller Energy Resources, Inc., formerly known as Miller Petroleum, Inc., and our subsidiaries, Miller Rig & Equipment, LLC, Miller Energy Colorado 2014-1, LLC, Miller Drilling, TN LLC, Miller Energy Services, LLC, East Tennessee Consultants, Inc. ("ETC"), East Tennessee Consultants II, LLC ("ETCII"), Miller Energy GP, LLC, Cook Inlet Energy, LLC ("CIE"), and Anchor Point Energy, LLC ("Anchor Point Pipeline") collectively.
	We are an independent exploration and production company that utilizes seismic data and other technologies for the geophysical exploration, development and production of oil and natural gas wells in southcentral Alaska, including the Cook Inlet and Kenai Peninsula. The accounting policies used by us and our subsidiaries reflect industry practices and conform to U.S. generally accepted accounting principles ("GAAP").
	Basis of Presentation
	The accompanying condensed consolidated financial statements are presented in accordance with GAAP and, in the opinion of management, include all adjustments (consisting only of normal recurring adjustments) necessary for a fair statement of the results for the interim periods. Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted under Securities and Exchange Commission ("SEC") rules and regulations. The results reported in these condensed consolidated financial statements are not necessarily indicative of the financial position or operating results that may be expected for the entire year.
	The financial information included herein should be read in conjunction with the audited consolidated financial statements and notes thereto included in Item 8 of Part II of the Company's Annual Report on Form 10-K for the year ended April 30, 2014, which was filed with the SEC on July 14, 2014, and amended on July 15, 2014.
	Certain amounts in prior fiscal years have been reclassified to conform with the presentation adopted in the current year.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	6 Months Ended
	Oct. 31, 2014
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Our significant accounting policies are consistent with those disclosed in our Annual Report on Form 10-K for the year ended April 30, 2014.
	Principles of Consolidation
	The accompanying condensed consolidated financial statements include our consolidated accounts after elimination of intercompany balances and transactions. The condensed consolidated financial statements also include the accounts of all investments in which we, either through direct or indirect ownership, have more than a 50% interest or significant influence over the management of those entities.
	Use of Estimates
	The preparation of financial statements requires us to utilize estimates and make judgments that affect the reported amounts of assets, liabilities, revenues and expenses and related disclosure of contingent assets and liabilities. These estimates are based on historical experience and on various other assumptions that we believe to be reasonable under the circumstances. The estimates are evaluated by management on an ongoing basis and the results of these evaluations form a basis for making decisions about the carrying value of assets and liabilities that are not readily apparent from other sources. Although actual results may differ from these estimates under different assumptions or conditions, we believe that the estimates used in the preparation of our financial statements are reasonable.
	Oil and Gas Properties
	We follow the successful efforts method of accounting for oil and gas properties. Under this method, exploration costs, such as exploratory geological and geophysical costs, delay rentals and exploration overhead, are charged against earnings as incurred. Acquisition costs and costs of drilling exploratory wells are capitalized pending determination of whether proved reserves can be attributed to the area as a result of drilling the well. If management determines that commercial quantities of hydrocarbons have not been discovered, capitalized costs associated with exploratory wells are charged to exploration expense.
	Costs of drilling and equipping successful wells, costs to construct or acquire facilities, and associated asset retirement costs are depleted using the unit-of-production method based on total estimated proved developed reserves. Costs of acquiring proved properties, including leasehold acquisition costs transferred from unproved properties and costs to construct or acquire offshore platforms, and associated asset retirement costs are depleted using the unit-of-production method based on total estimated proved reserves.
	When circumstances indicate that proved properties may be impaired, the Company compares expected undiscounted future net cash flows, calculated using the Company's estimate of future oil and natural gas prices, operating expenses and production, to the net book value of the proved properties on a field by field basis. If the sum of the expected undiscounted future net cash flows is less than the net book value of the proved properties, an impairment loss is recognized for the excess, if any, of the net book value over its estimated fair value. See Note 6 for a discussion of asset impairments.
	Acquisition costs of unproved properties are assessed for impairment during the holding period and transferred to proved oil and gas properties to the extent the costs are associated with successful exploration activities. Significant undeveloped leases are assessed individually for impairment based on our current exploration plans, and a valuation allowance is provided if impairment is indicated. Costs of expired or abandoned leases are charged to expense, while costs of productive leases are transferred to proved oil and gas properties. Costs of maintaining and retaining unproved properties are included in oil and gas operating expense and impairments of unsuccessful leases are included in exploration expense.
	Loss Per Share
	We determine basic income (loss) per share and diluted income (loss) per share in accordance with the provisions of ASC 260, “Earnings Per Share.” Basic income (loss) per share excludes dilution and is computed by dividing earnings available to common stockholders by the weighted-average number of common shares outstanding for the period. The calculation of diluted earnings (loss) per share is similar to that of basic earnings per share, except that the denominator is increased, if net income is positive, to include the number of additional common shares that would have been outstanding if all potentially dilutive common shares, such as those issuable upon the exercise of stock options and warrants, had been exercised. We compute the numerator for basic income (loss) by subtracting accretion of preferred stock and cumulative preferred stock dividends from net income (loss) to arrive at net income (loss) attributable to common stockholders. Preferred stock dividends include dividends declared on preferred stock (regardless of whether the dividends have been paid) and dividends accumulated for the period on cumulative preferred stock (regardless of whether the dividends have been declared). As of October 31, 2014, our cumulative preferred dividends were $6,406.
	Deferred Escalating Minimum Rent
	Certain of our operating leases contain predetermined fixed escalations of the minimum rentals during the term of the lease, which includes option periods where failure to exercise such options would result in an economic penalty. For these leases, we recognize the related rental expense on a straight-line basis over the life of the lease, beginning with the point at which we obtain control and possession of the leased properties, and record the difference between the amounts charged to operations and amounts paid as deferred escalating minimum rent. Any lease incentives received are deferred and subsequently amortized on a straight-line basis over the life of the lease as a reduction to rent expense.
	New Accounting Pronouncements Issued But Not Yet Adopted
	In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers (Topic 606)." ASU 2014-09 is intended to improve the financial reporting requirements for revenue from contracts with customers by providing a principle based approach. The core principle of the standard is that revenue should be recognized when the transfer of promised goods or services is made in an amount that the entity expects to be entitled to in exchange for the transfer of goods and services. ASU 2014-09 also requires disclosures enabling users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. This standard will be effective for financial statements issued by public companies for annual reporting periods beginning after December 15, 2016. Early adoption is not permitted. The Company is currently evaluating the potential impact of ASU 2014-09 on the condensed consolidated financial statements.
	In August 2014, the FASB issued ASU 2014-15, "Presentation of Financial Statements - Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern" that describes how an entity's management should assess whether there are conditions and events that raise substantial doubt about an entity's ability to continue as a going concern within one year after the date that the financial statements are issued. Management should consider both quantitative and qualitative factors in making its assessment. The new standard applies to all entities for the first annual period ending after December 15, 2016, and for annual and interim periods thereafter. Early application is permitted. The Company will assess the potential impact of ASU 2014-15 when applicable circumstances are present.
	New Accounting Pronouncements Issued and Adopted
	In April 2014, the FASB issued ASU 2014-08, "Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity." ASU 2014-08 changes the definition of a discontinued operation to include only those disposals of components of an entity that represent a strategic shift that has (or will have) a major effect on an entity's operations and financial results. In addition, ASU 2014-08 requires additional disclosures about both discontinued operations and the disposal of an individually significant component of an entity that does not qualify for discontinued operations presentation in the financial statements. The guidance is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2014, with early adoption permitted. We adopted the provisions of ASU 2014-08 on a prospective basis during the first quarter of fiscal year 2015. The adoption of this ASU did not have an impact on our condensed consolidated financial statements.
	There are no other recently issued accounting pronouncements that are expected to have a material impact on our financial condition, results of operations or cash flows.

Acquisitions

Acquisitions	6 Months Ended
	Oct. 31, 2014
Business Combinations [Abstract]	'
Acquisitions	'
	ACQUISITIONS
	Merger Agreement with Savant Alaska, LLC
	On May 8, 2014, we entered into an Agreement and Plan of Merger with Savant Alaska, LLC ("Savant") to acquire Savant, subject to due diligence and regulatory approval, for $9,000. We have formed a wholly-owned subsidiary, Miller Energy Colorado 2014-1, LLC, which will merge with Savant to facilitate the acquisition. Savant currently owns, and we would acquire as a result of this merger, a 67.5% working interest in the Badami Unit and 100% ownership in certain nearby leases. ASRC Exploration, LLC owns the remaining 32.5% working interest in the Badami Unit. In addition to the working interest in the Badami Unit and the leases, we would acquire certain midstream assets located in the North Slope with a design capacity of 38,500 bopd, a 500,000 gallon diesel storage tank, 20 megawatts of power generation, a grind and inject solid waste disposal facility and Class 1 disposal well, a one mile airstrip, and two pipelines each running 25 miles in length from the Badami Unit to the Endicott Pipeline. Production from the Savant assets was approximately 1,100 bopd gross (600 bopd net) at the time of our announcement of the acquisition.
	We expect the transaction to close by December 2014, following regulatory approval, with a May 1, 2014 effective date as defined in the Agreement and Plan of Merger.
	Anchor Point Pipeline Purchase
	The acquisition of the Anchor Point Pipeline, closed on August 8, 2014 upon receiving approval from the Regulatory Commission of Alaska. Purchase consideration consisted of Series D Preferred Stock with a fair market value of $5,446 on August 8, 2014, which was released from escrow upon closing.
	The purchase of the Anchor Point Pipeline has been accounted for under ASC 805, "Business Combinations." Under ASC 805, the Company is required to allocate the purchase price to assets acquired and liabilities assumed based on their fair values at the acquisition date. The estimated fair value of the properties approximates the fair value of consideration, and as a result, no goodwill was recognized. The following table summarizes the consideration paid for the Anchor Point Pipeline and the allocation of the purchase price to the assets acquired and liabilities assumed that have been included in the Company's condensed consolidated financial statements. The Company is in the process of finalizing the evaluation of the assigned fair values to the assets acquired and liabilities assumed.
	Purchase Price:
	Series D Preferred Stock	$	5,446
	Preliminary Allocation of Assets Acquired and Liabilities Assumed:
	Natural gas pipeline and pipeline support assets	$	5,687
	Asset retirement obligation	$	(241	)
	Fair value of assets acquired and liabilities assumed	$	5,446
	In conjunction with the Anchor Point Pipeline, it was necessary for us to estimate the values of the assets acquired and liabilities assumed, which involved the use of various assumptions. The most significant assumptions, and the ones requiring the most judgment, involved the estimated replacement costs of the pipeline and obsolescence. Assumptions were also made regarding the retirement obligation. With respect to the fair value, these assumptions are considered Level 3 inputs.
	Acquisition related costs included legal and other professional services charges.

Major_Customers_and_Concentrat

Major Customers and Concentrations of Credit Risk	6 Months Ended
	Oct. 31, 2014
Risks and Uncertainties [Abstract]	'
Major Customers and Concentrations of Credit Risk	'
	MAJOR CUSTOMERS AND CONCENTRATIONS OF CREDIT RISK
	For the three ended October 31, 2014, two customers accounted for 83% and 15% of our consolidated total revenues. For the six months ended October 31, 2014, two customers accounted for 82% and 14% of our consolidated total revenues. Two customers accounted for 11% and 19% of our consolidated accounts receivable as of October 31, 2014. Two customers accounted for 5% and 23% of our consolidated accounts receivable as of April 30, 2014.
	Credit is extended to customers based on an evaluation of their creditworthiness and collateral is generally not required. We experienced no credit losses of significance during the three and six months ended October 31, 2014 or 2013.
	We maintain our cash and cash equivalents (including restricted cash), which at times may exceed federally insured amounts, in highly rated financial institutions. As of October 31, 2014, we held $14,217 in excess of the $250 limit insured by the Federal Deposit Insurance Corporation.
	We have a risk of loss from counterparties not performing pursuant to the terms of their contractual obligations. We attempt to minimize credit-risk exposure to derivative counterparties through formal credit policies, consideration of credit ratings from public ratings agencies, monitoring procedures, master netting agreements and collateral support under certain circumstances. Collateral support could include letters of credit, payment under margin agreements and guarantees of payment by creditworthy parties. We also enter into master netting agreements to mitigate counterparty performance and credit risk. During the three and six months ended October 31, 2014 and 2013, we did not incur any significant losses due to counterparty bankruptcy filings. We assess our credit exposure on a net basis to reflect master netting agreements in place with certain counterparties. We offset our credit exposure to each counterparty with amounts we owe the counterparty under derivative contracts.

Related_Party_Transactions

Related Party Transactions	6 Months Ended
	Oct. 31, 2014
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	RELATED PARTY TRANSACTIONS
	We use a number of contract labor companies to provide on demand transportation and labor at our Alaska operations. H&H Industrial, Inc. ("H&H Industrial") is an entity contracted by CIE, a wholly-owned subsidiary of the Company, to provide services related to the exploration and production of oil and natural gas. H&H Industrial is owned by the sister and father of David Hall, who is Chief Operating Officer ("COO") of the Company. For the three and six months ended October 31, 2014, we recorded capital and lease operating expenses related to H&H Industrial of $985 and $1,703, respectively. The Audit Committee of our Board of Directors determined that the amounts paid by us for the services performed were fair and in the best interest of the Company.
	On December 9, 2014, the Company entered into a two-year consulting agreement with Deloy Miller under which he agreed to assist us with oil and gas related matters, including assisting with our strategic planning, providing management with drilling advice, and other consulting services we may reasonably request. As compensation for these services, the Company agreed to pay Mr. Miller $275 per year and granted Mr. Miller an option to purchase 100,000 shares of our common stock at an exercise price of $1.35 per share vesting in equal installments on the first and second anniversary of the date that the parties entered into the consulting agreement. Mr. Miller is a related party to the Company as a result of his former employment with the Company and his relationship to Mr. Boruff, the Company’s Executive Chairman, as his former father-in-law. The audit committee of our Board of Directors determined that the consideration given by us for the services to be performed was fair and in the best interest of the Company.

Oil_and_Gas_Properties_and_Equ

Oil and Gas Properties and Equipment	6 Months Ended
	Oct. 31, 2014
Property, Plant and Equipment [Abstract]	'
Oil and Gas Properties and Equipment	'
	OIL AND GAS PROPERTIES AND EQUIPMENT
	Oil and gas properties (successful efforts method) are summarized as follows:
		October 31,			April 30,
		2014			2014
	Property costs:
	Proved property	$	479,911		$	467,740
	Unproved property	93,498			243,230
	Total property costs	573,409			710,970
	Less: Accumulated depletion	(210,854		)	(66,143		)
	Oil and gas properties, net	$	362,555		$	644,827
	On October 31, 2014, the significant decline in crude oil prices during the second quarter of fiscal 2015 was identified as an impairment related triggering event for proved and unproved properties. The Redoubt Unit failed the step 1 test which is based on undiscounted cash flows. The failure of step 1 required the Company to measure the estimated fair value of the Redoubt Unit based on discounted cash flows. The step 2 analysis resulted in an impairment to proved and unproved properties of $112,414 and $152,887, respectively. The factors used to estimate the fair value of the Redoubt Unit include, but are not limited to, estimates of reserve quantities, future commodity prices, the timing of future production, operating costs, capital expenditures and a risk adjusted discount rate. Because these significant fair value inputs are typically not observable, we have categorized the amounts as Level 3 inputs. As of October 31, 2014, the proved and unproved properties of the Redoubt Unit were written down to their estimated fair value of $122,587.
	On October 31, 2014, the Company recorded a charge to exploration expense of $13,325 for Olsen Creek #2, which was determined to be a dry hole. In addition, on October 31, 2014, we recognized an impairment of $1,319 to write down the net assets of substantially all of our Tennessee oil and gas properties to reflect the expected sales price. These properties were sold on November 20, 2014.
	Equipment is summarized as follows:
		October 31,			April 30,
		2014			2014
	Machinery and equipment	$	5,997		$	7,759
	Vehicles	512			1,877
	Buildings	2,447			2,726
	Office equipment	1,180			1,108
	Leasehold improvements	677			527
	Drilling rigs	43,640			30,210
	Capital lease asset	3,678			1,500
	Natural gas pipeline and pipeline support assets	5,687			—
		63,818			45,707
	Less: Accumulated depreciation	(9,588		)	(10,338		)
	Equipment, net	$	54,230		$	35,369
	The Company classified its aircraft as an asset held for sale on our condensed consolidated balance sheets as of April 30, 2014 and October 31, 2014. The aircraft is recorded at estimated fair value less cost to sell. Proceeds received from the sale of the aircraft are required to pay down the Company's Second Lien Credit Facility (defined below).
	During the three months ended October 31, 2014, a substantial portion of our Tennessee assets were reclassified and presented as assets held for sale. The Company estimates the fair value of the assets and liabilities to be $5,072 and $1,495, respectively. The cost to sell the assets, including commissions and legal costs, are estimated to be $246. An impairment charge of $1,319 was recorded, representative of the excess of the assets carrying value over the estimated fair value less cost to sell. Because these significant fair value inputs are typically not observable, we have categorized the amounts as Level 3 inputs.
	Depreciation, depletion and amortization consisted of the following:
		For the Six Months Ended October 31,
		2014			2013
	Depletion of oil and gas related assets	$	35,026		$	12,532
	Depreciation and amortization of equipment	2,034			2,178
	Total	$	37,060		$	14,710
	We have obtained multiple reserve reports in the last twelve months due to our acquisition and drilling activity in Alaska. The reserve reports have provided incremental information to allow us to better understand the reserves on a field basis. These changes in reserve estimates have caused an increase in proved property depletion.
	Entry into Glacier Rig Purchase Option
	Effective as of July 4, 2014, we entered into a Purchase and Sale Agreement with Teras Oilfield Support Limited which grants us the right to purchase the Glacier Drilling Rig #1, a Mesa 1000 carrier-mounted land drilling rig, which we have renamed Rig 37 and related equipment. During the six months ended October 31, 2014, the Company paid $6,346 in connection with the acquisition of Rig 37 and has an obligation to pay an additional $654 upon the occurrence of certain conditions.
	Acquisition of Rig 36 and Related Capital Lease
	On May 5, 2014, we entered into a Rig Equipment Purchase Agreement with Baker Process, Inc. to purchase a 2400 HP rig, which we have named Rig 36, and related equipment. On May 9, 2014, the Company entered into a capital lease with First National Capital, LLC to finance the purchase of and planned future modifications to Rig 36. We have drawn $3,250 under the capital lease.

Derivative_Instruments

Derivative Instruments	6 Months Ended
	Oct. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments	'
	DERIVATIVE INSTRUMENTS
	Derivative Instruments
	Commodity Derivatives
	From time to time, we enter into derivative financial instruments to mitigate our exposure to crude oil price volatility. The derivative financial instruments, which are placed with financial institutions that we believe are acceptable credit risks, take the form of over-the-counter variable-to-fixed price commodity swaps. All derivative financial instruments are recognized in our condensed consolidated financial statements at fair value. The fair values of our derivative instruments are determined based on discounted cash flows derived from quoted forward prices. We do not use hedge accounting for commodity derivatives; thus, the open positions are recorded at fair value with the change in value recorded to earnings.
	We have experienced and could continue to earnings volatility due to fluctuations in the fair value of these commodity derivative contracts. The lack of hedge accounting has no impact on our reported cash flows, although our results of operations are affected by the volatility of mark-to-market gains and losses and changes in fair value, which fluctuate with changes in crude oil prices. These fluctuations could be significant in a volatile pricing environment.
	As of October 31, 2014, we had the following open crude oil derivative positions. All are priced based on the Brent crude oil futures as traded on the Intercontinental Exchange.
			Fixed - Price Swaps
	Production Period ending April 30,		Bbls			Weighted Average Fixed Price
	2015		389,600			98.71
	2016		787,600			95.36
	2017		232,600			93.97
	Derivative Activities Reflected on Condensed Consolidated Balance Sheets
	The following table presents the fair value of commodity derivatives. The fair value amounts are presented on a gross basis and do not reflect the netting of asset and liability positions permitted under the terms of our master netting arrangements.
			Asset Derivatives											Liability Derivatives
			October 31, 2014						April 30, 2014					October 31, 2014				April 30, 2014
	Derivatives not designated as hedging instruments under ASC 815		Balance Sheet Location		Fair Value				Balance Sheet Location		Fair Value			Balance Sheet Location		Fair Value		Balance Sheet Location	Fair Value
	Commodity derivatives		Prepaid expenses and other		$	7,222			Prepaid expenses and other		$	88		Current portion of derivative instruments		$	—	Current portion of derivative instruments	$	(3,315	)
	Commodity derivatives		Other assets		2,159				Other assets		26			Long-term portion of derivative instruments		—		Long-term portion of derivative instruments	(4,006		)
	Total derivatives not designated as hedging instruments under ASC 815				$	9,381					$	114				$	—		$	(7,321	)
	Offsetting of Derivative Assets and Liabilities
	The following table presents our gross and net derivative assets and liabilities:
		Gross Amount Presented on Balance Sheet				Netting Adjustments (a)				Net Amount
	October 31, 2014
	Derivative assets with right of offset or master netting agreements	$	9,381			$	—			$	9,381
	April 30, 2014
	Derivative assets with right of offset or master netting agreements	$	114			$	(114	)		$	—
	Derivative liabilities with right of offset or master netting agreements	$	(7,321	)		$	114			$	(7,207	)
	—————————
	(a)	The Company has an agreement in place that allows for the financial right of offset for derivative assets and derivative liabilities at settlement or in the event of default under the agreement.
	Derivative Activities Reflected on Condensed Consolidated Statements of Operations
	Gains and losses on derivatives are reported in the condensed consolidated statements of operations. The following represents the Company's reported gains and losses on derivative instruments for the periods presented:
		For the Three Months Ended October 31,								For the Six Months Ended October 31,
		2014				2013				2014			2013
	Gain (loss) on derivatives, net	$	23,089			$	(4,190	)		$	16,186		$	(7,266	)
	As of October 31, 2014, we did not maintain any derivative instruments that were classified as fair value hedges or trading securities. In addition, as of October 31, 2014, we did not maintain any derivative instruments containing credit risk contingencies.

Fair_Value_Measurements

Fair Value Measurements	6 Months Ended
	Oct. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	FAIR VALUE MEASUREMENTS
	Fair Value Measurement on a Recurring Basis
	The carrying amounts reported in the condensed consolidated balance sheets for cash and cash equivalents, trade receivables, account payables and other short-term liabilities approximate fair value due to the nature of the instrument and/or the short-term maturity of these instruments. Other fair value measurements are noted throughout the Notes to the Condensed Consolidated Financial Statements and the level of inputs classified. The fair values of the Company's commodity derivative instruments are classified as Level 2 measurements as they are calculated using industry standard models using assumptions and inputs which are substantially observable in active markets throughout the full term of the instruments. These include market price curves, contract terms and prices, credit risk adjustments, and discount factors. The following summarizes the fair value of the Company's commodity derivative assets and liabilities according to their fair value hierarchy as of the reporting dates indicated:
		Fair Value Measurements
	At October 31, 2014	Level 1		Level 2			Level 3
	Commodity derivative asset	$	—	$	9,381		$	—
	Total	$	—	$	9,381		$	—
	At April 30, 2014
	Commodity derivative asset	$	—	$	114		$	—
	Commodity derivative liability	—		(7,321		)	—
	Total	$	—	$	(7,207	)	$	—
	There were no transfers between Level 1, Level 2 or Level 3 during the six months ended October 31, 2014.

Debt

Debt	6 Months Ended
	Oct. 31, 2014
Debt Disclosure [Abstract]	'
Debt	'
	DEBT
	As of October 31, 2014 and April 30, 2014, we had the following debt obligations:
		October 31,				April 30,
		2014				2014
	Second Lien Credit Facility	$	175,000			$	175,000
	Debt discount related to Second Lien Credit Facility	(2,858		)		(3,296		)
	First Lien RBL	36,000				—
	Gunsight Promissory Note payable	950				950
	Apollo prepayment and extension fee note payable	4,612				9,223
	Capital lease obligation	2,951				—
	Series B Preferred Stock	2,363				2,325
	Total debt obligations	219,018				184,202
	Less: Current maturities	(6,095		)		(9,459		)
	Total debt less current maturities	$	212,923			$	174,743
	Second Lien Credit Facility
	On February 3, 2014, we refinanced our $100,000 credit facility with Apollo Investment Corp. ("Apollo") (the "Prior Credit Facility") by entering into a new Credit Agreement (the "Second Lien Credit Agreement") with Apollo and certain affiliates of Highbridge Capital Strategies (the "Second Lien Lenders") which set forth the terms of a credit facility of up to $175,000 (the "Second Lien Credit Facility").
	The Second Lien Credit Agreement provides for a $175,000 term credit facility, all of which was made available to and drawn by us on the closing date. The amounts drawn were subject to a 2% original issue discount. Absent an event of default, amounts outstanding under the Second Lien Credit Facility bear interest at a rate of LIBOR plus 9.75%, subject to a 2% LIBOR floor. The Second Lien Credit Facility permitted us to enter into a reserve-based revolving credit facility of up to $100,000 on certain agreed terms which would be secured on a first-lien basis. Upon entering into such revolving credit facility and a related intercreditor agreement, the Second Lien Credit Facility would become a second-lien credit facility. We entered into a credit agreement for a revolving credit facility (the "First Lien Loan Agreement"), among us, as borrower, KeyBank National Association ("KeyBank"), as administrative agent (in that capacity the "RBL Administrative Agent"), and the lenders from time to time party thereto (the "RBL Lenders") on June 2, 2014. The First Lien Loan Agreement provides for a $250,000 senior secured, reserve-based revolving credit facility (the "First Lien RBL"). In connection with our entry into the First Lien Loan Agreement, we amended the Second Lien Credit Agreement. The Second Lien Credit Facility carries a four year maturity. The Second Lien Credit Facility contains covenants, including but not limited to, a leverage ratio, interest coverage ratio, current ratio, asset coverage ratio, minimum gross production and change of management control covenants, as well as other covenants customary for a transaction of this type. As of October 31, 2014, there was an event of default under the Second Lien Credit Facility arising from Mr. Scott M. Boruff stepping down as chief executive officer of the Company (the "Second Lien Technical Default"). Additionally, we were not in compliance with certain of the required financial covenants as of October 31, 2014 (the "Second Lien Covenant Default"), although we were in compliance with the production and other covenants. The Second Lien Technical Default and Second Lien Covenant Default were waived or otherwise remedied by the December 2014 Second Lien Amendment, as described below in Note 16, Subsequent Events.
	We used $75,306 of the proceeds drawn under the Second Lien Credit Facility to refinance the Prior Credit Facility with Apollo and $56,577 to finance the acquisition of the North Fork unit. In addition, $3,071 was used to retire the obligations owed under the MEI Loan Documents. The remainder of the proceeds from the Second Credit Facility were used for general corporate purposes. The fair value of the outstanding balance of the Second Lien Credit Facility was $171,781 and $176,785 as of October 31, 2014 and April 30, 2014, respectively, as calculated using the discounted cash flows method. Level 3 inputs were used to calculate the fair value of the outstanding balance of the Second Lien Credit Facility.
	On the closing date, in connection with the Second Lien Credit Facility, we, along with all of our consolidated subsidiaries (other than MEI), entered into an Amended and Restated Guarantee and Collateral Agreement (the "Second Lien Guarantee") with Apollo, for the benefit of the lenders from time to time party to the Second Lien Credit Agreement. Under the terms of the Second Lien Guarantee and related security documents, each of our consolidated subsidiaries (other than MEI) have guaranteed our obligations under the Second Lien Credit Facility and we and those subsidiaries have granted a security interest in substantially all of their assets to secure the performance of the obligations arising under the Second Lien Credit Facility.
	On June 2, 2014, we entered into the Amendment No. 1 to Credit Agreement and Guarantee and Collateral Agreement to the Second Lien Credit Facility and the Second Lien Guarantee. This amendment conforms certain of the covenants, terms and conditions in the Second Lien Credit Facility to match those of the First Lien RBL, including the financial covenants.
	We entered into Amendment No. 2 to the Second Lien Credit Agreement, which amended a default provision to remove its reference to David Voyticky, our former president. Prior to this amendment, under the Second Lien Credit Agreement, the resignation of Mr. Voyticky would have been a default. In addition, this amendment removed references to Mr. Voyticky from certain defined terms used in the Second Lien Credit Agreement.
	We entered into Amendment No. 3 to the Second Lien Credit Agreement, dated as of August 19, 2014, to the Second Lien Credit Agreement, which (1) increased the total amount of obligations we may enter into under capital leases from time to time, (2) allowed us to make certain investments in Savant, and (3) increased the amount of preferred stock that we may issue, among other things.
	First Lien RBL
	On June 2, 2014, we entered into the First Lien Loan Agreement, among the Company, as borrower, KeyBank, as the RBL Administrative Agent, and the RBL Lenders. In addition to KeyBank, the syndicate includes CIT Finance LLC, Mutual of Omaha Bank and OneWest Bank N.A.
	The First Lien Loan Agreement provides for a $250,000 senior secured, reserve-based revolving credit facility, $60,000 of which was made available to us on the closing date. The borrowing base will be redetermined semi-annually on February 1st and August 1st of each year. Amounts outstanding under the First Lien RBL are priced on a sliding scale, based on LIBOR plus 300 to 400 basis points, depending upon the level of borrowing (per the table below).
	Borrowing Base Utilization Grid
	Borrowing base utilization percentage	<25%	≥ 25%, but <50%	≥ 50%, but <75%	≥ 75%, but <90%	≥ 90%, but ≤100%
	Spread above LIBOR	3.00%	3.25%	3.50%	3.75%	4.00%
	Undrawn commitment fee rate	0.50%	0.50%	0.75%	0.75%	0.75%
	The First Lien RBL will expire on the third anniversary of its closing. It contains customary covenants, including, but not limited to, a leverage, interest coverage, current ratio, minimum gross production, minimum liquidity, asset coverage and change of management control covenants.  Due to the existence of the Second Lien Technical Default which arose when Scott M. Boruff stepped down as chief executive officer of the Company, as of October 31, 2014, there was an event of default under the First Lien Loan Agreement’s cross default provision (the "First Lien Technical Default"). Additionally, we were not in compliance with certain of the required financial covenants as of October 31, 2014 (the "First Lien Covenant Default"), although we were in compliance with the production and other covenants. The First Lien Technical Default and First Lien Covenant Default were waived or otherwise remedied by the December 2014 First Lien Amendment, as described below in Note 16, Subsequent Events.
	The Company drew $20,000 on the closing date under the First Lien RBL, which was used to provide working capital for development drilling in Alaska. The amounts available were subject to an upfront fee equal to 1% of the initial borrowing base. On June 20, 2014, we requested an additional $10,000, which was funded on June 24, 2014. We repaid borrowings of $10,000 during the six months ended October 31, 2014, and drew down $16,000 on August 1, 2014. The fair value of floating-rate debt approximates the carrying amount because the interest rates paid are based on short-term maturities.
	Also on June 2, 2014, in connection with the First Lien RBL, we, along with all of our consolidated subsidiaries (other than MEI, Miller Energy Colorado 2014-1, LLC, and Miller Drilling 2009-A, L.P.), entered into a First Lien Guarantee and Collateral Agreement (the "First Lien Guarantee") with KeyBank, for the benefit of the RBL Lenders from time to time party to the First Lien Loan Agreement. Under the terms of the First Lien Guarantee and related security documents, each of our consolidated subsidiaries (other than MEI, Miller Energy Colorado 2014-1, LLC, and Miller Drilling 2009-A, L.P.) have guaranteed the obligations under the First Lien RBL. Along with the aforementioned subsidiaries, we have granted a security interest in substantially all of our assets to secure the performance of the obligations arising under the First Lien RBL.
	On August 11, 2014, we entered into the First Amendment to our First Lien Loan Agreement, which amended a default provision to remove its reference to Mr. Voyticky. Prior to this amendment, under the First Lien Loan Agreement, the resignation of Mr. Voyticky would have been a default. In addition, this amendment removes references to Mr. Voyticky from certain defined terms used in the First Lien Loan Agreement.
	On August 19, 2014, we entered into the Second Amendment to our First Lien Loan Agreement, which (1) increases the total amount of obligations we may enter into under capital leases from time to time, (2) allows us to make certain investments in Savant, and (3) increases the amount of preferred stock that we may issue, among other things.
	Series B Preferred Stock
	The outstanding Series B Preferred Stock is classified as long-term debt in accordance with ASC 480, "Distinguishing Liabilities from Equity." As of October 31, 2014 and April 30, 2014, the fair value of Series B Preferred Stock was $2,075 and $2,197, respectively, as calculated using the discounted cash flow method. The fair value of the our Series B Preferred Stock is classified as a Level 3 measurement as the fair value is calculated using a discounted cash flow model.
	On July 28, 2014, our Board approved a semiannual dividend to shareholders of approximately $6.05 per share on our Series B Preferred Stock, which was paid on the next regularly scheduled divided payment date of September 2, 2014, in accordance with the terms of our charter, as September 1, 2014 was not a business day. The dividend payment is equivalent to an annualized 12% per share, based on the $100.00 per share stated liquidation preference for the Series B Preferred Stock, accruing from March 2014 through August 2014. The record date, as required in accordance with our charter, was August 15, 2014.
	Debt Issue Costs
	As of October 31, 2014 and April 30, 2014, our unamortized deferred financing costs were $2,385 and $803, respectively, which relates to the First Lien RBL and the Second Lien Credit Facility. These costs are being amortized over the term of the respective debt instruments.

Asset_Retirement_Obligations

Asset Retirement Obligations	6 Months Ended
	Oct. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]	'
Asset Retirement Obligations	'
	ASSET RETIREMENT OBLIGATIONS
	The following table presents changes to the Company's asset retirement obligation ("ARO") liability for the six months ended October 31, 2014 and 2013:
		2014			2013
	Asset retirement obligation, as of April 30,	$	22,872		$	19,890
	Additions, including Anchor Point Pipeline	262			—
	Revisions	(99		)	—
	Accretion expense	697			598
	Settlements	(121		)	(16		)
	North Fork properties purchase price adjustment	159			—
	Asset retirement obligation, as of October 31,	$	23,770		$	20,472
	Less: Asset retirement obligation related to assets held for sale	(1,494		)	—
	Revised asset retirement obligation, as of October 31,	$	22,276		$	20,472
	The ARO liability reflects the estimated present value of the amount of dismantlement, removal, site reclamation, and similar activities associated with the Company's oil and gas properties. The Company utilizes current retirement costs to estimate the expected cash outflows for retirement obligations. The Company estimates the ultimate productive life of the properties, a risk-adjusted discount rate, and an inflation factor in order to determine the current present value of this obligation. To the extent future revisions to these assumptions impact the present value of the existing ARO liability, a corresponding adjustment is made to the oil and gas property balance.
	Any additional retirement obligations will increase the liability associated with new oil and natural gas wells and other facilities. Actual expenditures for abandonments of oil and natural gas wells and other facilities reduce the liability for asset retirement obligations.

StockBased_Compensation

Stock-Based Compensation	6 Months Ended
	Oct. 31, 2014
Share-based Compensation [Abstract]	'
Stock-Based Compensation	'
	STOCK-BASED COMPENSATION
	During fiscal years 2010 and 2011, our Compensation Committee and Board of Directors adopted share-based compensation plans authorizing 3,000,000 and 8,250,000 shares of common stock under each plan, respectively. On April 16, 2014, the number of shares of common stock available for issuance increased by 5,000,000 shares of common stock under the 2011 Equity Compensation Plan (the "2011 Plan"). The amendment to the 2011 Plan providing for the increase was adopted by our Board of Directors on March 10, 2014, and approved by our shareholders on April 16, 2014. On October 30, 2014, the number of shares of common stock available for issuance increased by 2,500,000 shares of common stock under the 2011 Plan. The amendment to the 2011 Plan providing for the increase was adopted by our Board of Directors on September 14, 2014, and approved by our shareholders on October 30, 2014. The share-based compensation plans allow us to offer our employees, officers, directors and others an opportunity to acquire a proprietary interest in the Company and enable us to attract, retain, motivate and reward such persons in order to promote our success. Each plan authorizes the issuance of incentive stock options, nonqualified stock options and restricted stock.  All awards issued under the share-based compensation plans must be approved by our Compensation Committee. At October 31, 2014 and April 30, 2014, there were 59,166 and 2,500 shares available under the 2010 Plan, respectively, and 2,483,423 and 3,132,078 additional shares available under the 2011 Plan, respectively.
	Allocated between general and administrative expenses and cost of oil and gas sales within the condensed consolidated statements of operations is stock-based compensation expense for the three and six months ended October 31, 2014 of approximately $7,414 and $9,059, respectively, and $1,469 and $3,025 for the three and six months ended October 31, 2013, respectively. We also recognized non-employee expense related to warrants issued for the three and six months ended October 31, 2014 of approximately $158 and $574, respectively, and $439 and $549 for the three and six months ended October 31, 2013, respectively.
	The following table summarizes stock options and warrants activity for the period presented:
		Number of Options and Warrants		Weighted Average Exercise Price
	Beginning balance at April 30, 2014	15,021,347		$	4.99
	Granted	2,670,500		4.59
	Exercised	(321,354	)	4.44
	Cancelled	(386,512	)	5.14
	Ending balance	16,983,981		4.93
	Options and warrants exercisable at October 31, 2014	13,376,916		$	4.87
	The following table summarizes stock options and warrants outstanding, including exercisable shares at October 31, 2014:
	Options and Warrants Outstanding							Options and Warrants
								Exercisable
	Range of Exercise Price		Number Outstanding		Weighted Average Remaining Contractual Life (in years)	Weighted Average Exercise Price		Number Exercisable	Weighted Average Exercise Price
	$0.01 to $1.82		1,480,200		0.7	$	0.7	1,480,200	$	0.7
	$2.00 to $4.99		3,886,334		7.4	4.04		2,199,769	3.76
	$5.15 to $5.53		4,137,447		2.5	5.32		3,641,947	5.33
	$5.68 to $5.94		3,535,000		6.1	5.91		3,295,000	5.92
	$6.00 to $6.95		3,945,000		3.1	6.13		2,760,000	6.15
			16,983,981		4.3	$	4.93	13,376,916	$	4.87
	The following table summarizes restricted stock activity for the six months ended October 31, 2014:
	Unvested at April 30, 2014	465,432
	Granted	930,655
	Vested	(1,139,754	)
	Cancelled	(25,000	)
	Unvested at October 31, 2014	231,333

Stockholders_Equity

Stockholders' Equity	6 Months Ended
	Oct. 31, 2014
Stockholders' Equity Note [Abstract]	'
Stockholders' Equity	'
	STOCKHOLDERS' EQUITY
	Common Stock
	At October 31, 2014, we had 46,599,471 shares of common stock outstanding. We issued 842,774 shares during the six months ended October 31, 2014, of which 521,420 shares were issued to employees for compensation, and 321,354 shares were related to the exercise of equity rights.
	Series D Preferred Stock
	During the three months ended October 31, 2014, we sold 16,120 shares of our 10.5% Series D Fixed Rate/Floating Rate Cumulative Redeemable Preferred Stock (the "Series D Preferred Stock") pursuant to an "at-the-market" offering, yielding net proceeds of $400.
	On August 25, 2014, we completed and closed a public offering of our 10.5% Series D Preferred Stock liquidation preference $25.00 per share. We issued 750,000 shares which were offered to the public at $24.50 per share for gross proceeds of $18,375. We incurred issuance costs of $1,352, yielding net proceeds of $17,023.
	Dividends Declared on Preferred Stock
	The following table summarizes the Series C Preferred Stock and Series D Preferred Stock dividend activity for the six months ended October 31, 2014.
	Series	Declaration Date	Dividend per Share		Annualized Percentage Rate		Par Value		Accrual Period	Record Date	Payment Date
	C	July 28, 2014	$	0.67	10.75	%	$	25	Jun. 1 - Aug. 31, 2014	August 15, 2014	September 2, 2014
	D	July 28, 2014	$	0.66	10.5	%	$	25	Jun. 1 - Aug. 31, 2014	August 15, 2014	September 2, 2014
	C	October 29, 2014	$	0.67	10.75	%	$	25	Sept. 1 - Nov. 30, 2014	November 14, 2014	December 1, 2014
	D	October 29, 2014	$	0.66	10.5	%	$	25	Sept. 1 - Nov. 30, 2014	November 14, 2014	December 1, 2014
	Fair Value Measurements
	The estimated fair value of our Series C and Series D Preferred Stock is $71,684 and $47,171 as of October 31, 2014, respectively, and $77,976 and $31,330 as of April 30, 2014, respectively.

Income_Taxes

Income Taxes	6 Months Ended
	Oct. 31, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	INCOME TAXES
	We have a significant deferred income tax liability related to the excess of the book carrying value of oil and gas properties over their collective income tax bases. This difference will reverse (through lower tax depletion deductions) over the remaining recoverable life of the properties, resulting in future taxable income in excess of income for financial reporting purposes. As an independent producer of domestic oil and gas, we take advantage of certain elective provisions presently in the Internal Revenue Code allowing for expensing of specified intangible drilling and development costs that are typically capitalized for book purposes. This temporary difference also reverses over the remaining life of the properties. As a result of these elections, we presently have U.S. federal and state net operating loss carryovers that are expected to be fully utilized against future taxable income resulting solely from the reversal of the temporary differences between the book carrying value of oil and gas properties and their tax bases. Our provision for income taxes for the second interim reporting period in fiscal 2015 is based on the actual year-to-date effective rate, as this is our best estimate of our annual effective tax rate for the full fiscal year. The computation of the annual effective tax rate includes a forecast of our estimated "ordinary" income (loss), which is our annual income (loss) from operations before tax, excluding unusual or infrequently occurring (or discrete) items. Significant management judgment is required in the projection of ordinary income (loss) in order to determine the estimated annual effective tax rate. The level of income (or loss) projected for fiscal 2015 causes an unusual relationship between income (loss) and income tax expense (benefit), with small changes resulting in: (i) a potential significant impact on the rate and, (ii) potentially unreliable estimates. As a result, we computed the provision for income taxes for the three and six month periods ended October 31, 2014 and October 31, 2013 by applying the actual effective tax rate to the year-to-date income (loss), as permitted by GAAP. The effective tax rate for the year-to-date period ended October 31, 2014 is a benefit of (41%). The principal differences in our effective tax rate (benefit) for this period and the federal statutory rate of 35% are state income taxes, change in state and local income taxes net of federal benefit and a valuation allowance against our Tennessee net operating loss carry-forwards and credits.  No other valuation allowances were deemed necessary in order to fully benefit the Company's year-to-date loss due to the presence of sufficient future taxable income related to the excess of book carrying value in oil and gas properties over their corresponding tax bases.  No other sources of taxable income were considered by Management in reaching this conclusion. No significant cash payments of income taxes were made during the year-to-date period ended October 31, 2014, and no significant payments are expected during the succeeding 12 months.

Alaska_Production_Credits

Alaska Production Credits	6 Months Ended
	Oct. 31, 2014
Alaska Production Credits [Abstract]	'
Alaska Production Credits	'
	ALASKA PRODUCTION CREDITS
	Upon qualifying, the Company can apply for several credits under Alaska Statutes 43.55.023 and 43.55.025:
	•	43.55.023(a)(1) Qualified capital expenditure credit (20%)
	•	43.55.023(l)(1) Well lease expenditure credit (effective June 30, 2010) (40%)
	•	43.55.023(a)(2) Qualified capital exploration expenditure credit (20%)
	•	43.55.023(l)(2) Well lease exploration expenditure credit (effective June 30, 2010) (40%)
	•	43.55.023(b) Carried-forward annual loss credit (25%)
	•	43.55.025 Seismic exploration credits (40%)
	We recognize a receivable when the amount of the credit is reasonably estimable and receipt is probable. For expenditure and exploration based credits, which we receive in the ordinary course of business, the credit is recorded as a reduction to the related assets. For carried-forward annual loss credits, which we receive in the ordinary course of business, the credit is recorded as a reduction to the Alaska production tax. We did not incur any Alaska production taxes in fiscal 2014, 2013 or 2012, and accordingly, the carried-forward annual loss credits are presented separately in our operating expenses on the condensed consolidated statements of operations.
	Balance, April 30, 2014	$	49,121
	Alaska carried-forward annual loss credits, net 1	2,732
	Applications for expenditure and exploration based credits 1	41,843
	Cash collections for expenditure and exploration based credits	(56,012		)
	Balance, October 31, 2014	$	37,684
	———————————
	1	Applications for carried-forward annual loss credits and for expenditure and exploration based credits are recorded net of established reserves and also include revisions to prior period applications, if applicable.
	During the six months ended October 31, 2014, we recorded net carried-forward annual loss credits of $2,732. We have reduced the basis of capitalized assets by a cumulative total of $84,770 for expenditure and exploration credits. The reductions are recorded on our condensed consolidated balance sheets in oil and gas properties and equipment. As of October 31, 2014 and April 30, 2014, we had outstanding net receivables from the State of Alaska in the amount of $37,684 and $49,121, respectively.

Litigation

Litigation	6 Months Ended
	Oct. 31, 2014
Loss Contingency, Information about Litigation Matters [Abstract]	'
Litigation	'
	LITIGATION
	On May 17, 2011, we were served with a lawsuit filed in the United States District Court for the Eastern District of Tennessee at Knoxville by Troy D. Stafford, the former Chief Financial Officer of CIE.  The suit, styled Troy D. Stafford v. Miller Petroleum, Inc., Civil Action No. 3-11CV-206, claims that we terminated Mr. Stafford's employment without cause in contravention of the terms of the Purchase and Sale Agreement between us and the sellers of CIE ("PSA"), failed or refused to pay his salary, severance, percentage of purchase price, expenses or stock warrants and violated a duty of good faith and fair dealing. The suit sought damages in excess of $3,000, which includes $2,687 of damages for loss of vested warrants. We believe that all of the asserted claims were baseless, particularly in view of the fact that we issued the warrants in accordance with the terms of the PSA.  We believe that we had appropriate cause to dismiss Mr. Stafford's employment after discovering that he had breached certain representations and warranties in the PSA, and had acted in violation of our Code of Conduct. We filed our Answer and conducted discovery. On January 21, 2013, Mr. Stafford's attorney filed a motion to withdraw as counsel, and on April 2, 2013, Mr. Stafford filed a motion to proceed pro se. On February 24, 2014, we filed a Motion to Dismiss with Prejudice based on Plaintiff's failure to prosecute his case since April 2, 2013, Plaintiff's having missed filing deadlines, and his having failed to appear to give his deposition both times we have noticed it. On February 26, 2014, the Court entered an Order to Show Cause, requiring the plaintiff to demonstrate why his case should not be dismissed. On March 14, 2014, the plaintiff filed a Motion for Voluntary Dismissal, Without Prejudice through his new attorney. On June 3, 2014, the court granted plaintiff's motion to dismiss without prejudice, but did so with the condition that plaintiff must reimburse us for costs incurred by us as a result of his failure to cooperate in discovery in this case in the amount of $9 prior to his being allowed to refile the case. As such, this case has been dismissed and there is no further action currently required.
	On June 15, 2011, a breach of contract lawsuit was filed against us and CIE in the United States District Court for the Eastern District of Pennsylvania styled VAI, Inc. v. Miller Energy Resources, Inc., f/k/a Miller Petroleum, Inc. and Cook Inlet Energy, LLC. The Plaintiff alleges three causes of action: (1) breach of contract, (2) unjust enrichment, and (3) breach of the implied covenant of good faith and fair dealing. The case seeks damages in warrants to purchase our common stock and monetary damages for certain fees and expenses. The Sale Agreement with David Hall, Walter "JR" Wilcox, and Troy Stafford dated December 10, 2009 contains indemnification provisions relevant to this claim. We filed a Motion to Dismiss for lack of personal jurisdiction, but this motion was not granted by the court. We filed an Answer to the complaint in this case on October 10, 2012, and we have conducted discovery. Trial was previously set for November 4, 2013. On October 21, 2013, the trial was postponed with no new trial date having been set. On October 31, 2013, the judge ruled on our outstanding Motion for Summary Judgment, granting it as to the unjust enrichment claim and breach of the implied covenant of good faith and fair dealing claim, and denying it as to the breach of contract claim. We expect to proceed to trial on the breach of contract claim once a new trial date is set. In February 2014, we received notice from a third party seeking to intervene in the case in order to secure payment of a debt allegedly owed by the Plaintiff to the third party. On May 29, 2014, the court put down a new scheduling order setting forth certain pre-trial deadlines with the final pre-trial conference being set for October 30, 2014. On June 5, 2014, the court entered an order denying the motion to intervene. On November 13, 2014, the court entered an order setting the trial date for this matter on January 20, 2015. Given the current stage of the proceedings in this case, we currently cannot assess the probability of losses, or reasonably estimate the range of losses, related to this matter.
	In August 2011, several purported class action lawsuits were filed against us in the United States District Court for the Eastern District of Tennessee.  The lawsuits made similar claims and have been consolidated into one case, styled In re Miller Energy Resources, Inc. Securities Litigation. The suit names us, along with several of our current and former executive officers, Scott Boruff, Paul Boyd, Ford Graham, David Hall, David Voyticky, and Deloy Miller, as defendants. The Plaintiffs allege two causes of action against the defendants: (1) violation of Section 10(b) and Rule 10b-5 of the Exchange Act, (2) violation of Section 20(a) of the Exchange Act.  The case seeks money damages against us and the other defendants, and payment of the Plaintiffs' attorney's fees. We have filed a Motion to Dismiss the case, which was denied on February 4, 2014 as to all defendants save Ford Graham. On July 3, 2014, we agreed upon a potential settlement with the Plaintiffs would dismiss the lawsuit with prejudice in exchange for a settlement payment of $2,950, which is within the remaining policy limits of our director and officer insurance policy. The proposed settlement remains subject to court approval and class notice administration before it will be effective.  Our final settlement is pending court approval, with an approval hearing set for February 3, 2015.
	On August 23, 2011, a derivative action was filed against us in Knox County Chancery Court.  The case is styled Marco Valdez, derivatively on behalf Miller Energy Resources, Inc. v. Deloy Miller, Scott M. Boruff, Jonathan S. Gross, Herman Gettelfinger, David Hall, Merrill A. McPeak, Charles M. Stivers, Don A. Turkleson, and David J. Voyticky, and Miller Energy Resources, Inc., nominal defendant.  The suit alleged the following causes of action: (1) Breach of Fiduciary Duty for disseminating false and misleading information; (2) Breach of Fiduciary Duty for failure to maintain internal controls; (3) Breach of Fiduciary Duty for failing to properly oversee and manage the company; (4) Unjust Enrichment; (5) Abuse of Control; Gross Mismanagement, and; (6) Waste of Corporate Assets.  The Plaintiff sought unspecified money damages from the individual defendants, that we take certain actions with respect to our management, restitution to us, and the Plaintiff's attorney fees and costs. The Plaintiff agreed to stay this case awaiting a ruling on the plaintiff's appeal in the federal derivatives case in Lukas v. Miller Energy Resources, Inc., et al, which, as disclosed in the Company’s prior periodic reports, was ultimately dismissed in our 2014 fiscal year. The Plaintiff had agreed to voluntarily dismiss the Valdez case in the event the plaintiff's appeal in Lukas was denied. Following the dismissal of Lukas, on October 1, 2013, the Court entered an Order dismissing the Valdez case without prejudice on the motion of the Plaintiff. On October 24, 2013, we filed a Motion to Amend the Order of Dismissal as the agreement with the Plaintiff was that the case would be dismissed with prejudice if the Sixth Circuit Court of Appeals affirmed the dismissal of the Lukas case, which it did. On June 3, 2014, after reaching an agreement with the Plaintiff, we filed an amended agreed final order of dismissal with prejudice in this case. This case has been dismissed and there is no further action required.
	On August 31, 2012, we terminated an agreement with Voorhees Equipment and Consulting, Inc. (“Voorhees”) for the construction and sale of the rig currently being used on the Osprey Platform, Rig 35, (the “Rig 35 Agreement”). We terminated the agreement based on our belief that Voorhees was in breach of its obligations thereunder.  Voorhees later indicated its desire to arbitrate claims it believes it has under invoices arising between May 29, 2012 and August 31, 2012.  We believed we had grounds to dispute liability with respect to some or all of those invoices, in addition to having certain counterclaims we expected to assert.  The parties elected to engage a private arbitrator to settle this dispute (the “Voorhees Matter”) and conducted discovery.  On September 18, 2013, we received a third-party complaint from Voorhees in connection with a lawsuit by Carlile Transportation Systems, Inc., in the Superior Court for the State of Alaska. The case is styled Carlile Transportation Systems, Inc. v. Voorhees Rig International, Inc. v. Cook Inlet Energy, LLC (the "Carlile Matter"). The dispute in the Carlile Matter related solely to unpaid transportation fees arising from the transportation of equipment for Rig 35. These fees were already the subject of the planned arbitration with Voorhees over the Voorhees Matter. As all disputes under the Rig 35 Agreement are subject to mandatory arbitration, we filed a motion to compel arbitration in the Carlile Matter, which the Court granted, along with an award of our legal costs incurred in connection with the Carlile Matter. On February 20, 2014, we reached an agreement in principle to settle the Voorhees Matter (including the transportation fees at issue in the Carlile Matter), and we entered into a settlement agreement which was effective as of May 12, 2014. We agreed to return to Voorhees the following equipment previously delivered to us under the Rig 35 Agreement, but which we subsequently replaced on that rig:
	•	an iron roughneck that we had to replace on Rig 35 due to mechanical unreliability; and
	•	a BOP stack originally included on Rig 35, but later removed and replaced with a better functioning replacement.
	We also agreed to return, and have since returned, to Voorhees two moving containers, left-over electrical equipment and tools belonging to Voorhees but left with CIE when Voorhees ceased working on Rig 35. No costs of defense or other cash payment were required of us in connection with this settlement, although we did pay the transportation costs of the equipment being returned. As a result, we recorded a gain of $113 related to this settlement in other income (expense), net in our condensed consolidated statement of operations for the six months ended October 31, 2014. As this matter has been resolved, no further action is required.
	On April 4, 2013, we filed suit against a former contractor of CIE and its parent company (collectively “Cudd”) in the United States District Court for the District of Alaska at Anchorage. This case is styled Cook Inlet Energy, LLC v. Cudd Pressure Control Inc. and RPC, Inc. In our suit we are seeking declaratory relief and damages for breach of contract, breach of the implied warranty of merchantability, breach of the implied covenant of fitness for a particular purpose and breach of the implied covenant of good faith and fair dealing arising out of a dispute regarding certain equipment and services provided by Cudd on the Osprey Platform that did not meet our needs or expectations as promised. We have not yet determined the full amount of damages claimed. On May 29, 2013, Cudd filed its Answer denying our claims and including a counterclaim for equipment and services, totaling approximately $1,889 plus the costs of defense. We have filed our counteranswer and denied that these amounts are owed, in whole or in part. We are presently conducting discovery. Given the current stage of the proceedings with respect to this case, we believe that any loss would be limited to $1,889 plus the cost of defense, related to this matter. Based on the information currently available, we have accrued our best estimate of the potential loss on our condensed consolidated balance sheet.
	On February 7, 2014, we were served with a lawsuit filed by Vulcan Capital Corporation ("Vulcan") in the District Court for the Southern District of New York styled Vulcan Capital Corp. v. Miller Energy Resources, Inc. and PlainsCapital Bank. The suit asserts various causes of action against PlainsCapital Bank, and appears to assert the following causes of action against us: (1) Breach of Fiduciary Duty and (2) Concert of Action. The case stems from an agreement Vulcan had with PlainsCapital Bank wherein Vulcan secured certain loans by pledging four warrants to purchase our common stock that were issued as part of the employment package of Ford F. Graham, our former President. Upon Vulcan's default of the loan agreement, PlainsCapital Bank presented the warrants to us for transfer, and, after requesting certain tenders required under Tennessee law, we registered the transfer of the warrants. We have retained counsel and we have filed a Motion to Transfer as the warrants have a valid exclusive forum clause that requires the case be tried in Knox County, Tennessee, but the case was transferred to Texas. We filed a motion to dismiss the case against the Company on October 9, 2014, and we are currently awaiting a ruling on the motion. In addition, PlainsCapital Bank has agreed to indemnify us for our first $500 of expenses related to this dispute. Given the current state of the proceedings in this case, we currently cannot assess the probability of losses, or reasonably estimate the range of losses, related to this matter.
	We are also party to various routine legal proceedings arising in the ordinary course of our business. Management believes that none of these actions, individually or in the aggregate, will have a material adverse effect on our financial condition or results of operations.

Subsequent_Events

Subsequent Events	6 Months Ended
	Oct. 31, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	SUBSEQUENT EVENTS
	Divestiture of Tennessee Assets
	On November 20, 2014, we closed the previously announced sale of substantially all of our Tennessee oil and gas assets for a purchase price of approximately $3,250 in cash. We also liquidated substantially all of our remaining oil and gas inventory in that State, yielding approximately $600 in net cash proceeds in addition to the purchase price.
	Payment of Dividends
	The following table summarizes the Series C Preferred Stock and Series D Preferred Stock dividend activity subsequent to October 31, 2014.
	Series	Declaration Date	Dividend Paid per Share		Annualized Percentage Rate		Par Value		Accrual Period	Record Date	Payment Date
	C	29-Oct-14	$	0.67	10.75	%	$	25	Sept. 1 - Nov. 30, 2014	14-Nov-14	1-Dec-14
	D	29-Oct-14	$	0.66	10.5	%	$	25	Sept. 1 - Nov. 30, 2014	14-Nov-14	1-Dec-14
	First Lien RBL Amendment
	On December 10, 2014, our company (the “Company”) entered into a Third Amendment (the "First Lien Amendment") to our Credit Agreement, dated as of June 2, 2014 (the “First Lien Credit Agreement”), among our Company, as borrower, KeyBank National Association, as administrative agent (the “First Lien Agent”), and the lenders party thereto (the “First Lien Lenders”) and to our Guarantee and Collateral Agreement, dated as of June 2, 2014 among our Company and its subsidiaries and the First Lien Agent. The First Lien Amendment, among other things, (1) amends our leverage and interest covenants, (2) establishes approved plans of development (“Plans”) and defines “Permitted Capital Expenditures” and adds requirements for the development of the our drilling program within those Plans and restricts our ability to engage in capital expenditures other than Permitted Capital Expenditures, (3) permits us to issue an additional $25,000 in preferred stock, measured in terms of the stated liquidation preference of that stock (to a total of $50,000 in stated liquidation preference in total), (4) adjusts the percentage by value of our oil and gas properties that must be the subject of mortgages in favor of the First Lien Agent (for the benefit of the First Lien Lenders) from 80% to 90%, (5) includes Mr. Carl F. Giesler, Jr., our Chief Executive Officer, as one of the officers designated in the definition of “Change of Control,” (6) eliminates restrictions on the sale of equity interests by Mr. Deloy Miller without impacting that “Change of Control” definition, (7) provides waivers related to certain events of default which arose as a result of Mr. Scott M. Boruff’s resignation as our Chief Executive Officer and certain sales of equity interests by Mr. Boruff as well as in connection with the scheduled payment of dividends on our preferred stock that occurred while an event of default had occurred, (8) extends the date by which the Company must remediate the material weakness in its internal controls over financial reporting from April 30, 2015 to April 30, 2016, but requires an additional borrowing base redetermination, unless waived by the majority of the First Lien Lenders, in the event our April 30, 2015 audited financial statements are issued with any qualification as to the effectiveness of our internal controls over financial reporting, (9) makes certain technical amendments intended to allow us to close the acquisition of Savant by easing certain requirements (which would have applied after that acquisition in the absence of this First Lien Amendment) related to its subsidiary, Nutaaq Pipeline, LLC, (10) requires that we not permit the aggregate revolving credit exposure of the First Lien Lenders to exceed $50,000 in the aggregate prior to next redetermination date for our borrowing base, scheduled for February 1, 2015 and (11) requires that the next receipt of tax credits by our Company be used as a prepayment of the outstanding loans under the First Lien Credit Agreement; provided that we receive that payment before the next scheduled redeterminaton date of our borrowing base, we agree not to permit the aggregate revolving credit exposure of the First Lien Lenders to exceed $40,000 in the aggregate.
	Second Lien Amendment
	On December 10, 2014, we entered into Waiver and Amendment No. 4 to Credit Agreement and Amendment No. 2 to Guarantee and Collateral Agreement (the “Second Lien Amendment”) to our Credit Agreement, dated as of February 3, 2014 (the “Second Lien Credit Agreement”), among our Company, as borrower, Apollo Investment Corporation, as administrative agent (the “Second Lien Agent”), and the lenders party thereto (the “Second Lien Lenders”) and our Guarantee and Collateral Agreement, dated as of February 3, 2014 among our Company and its subsidiaries and the Second Lien Agent. The Second Lien Amendment, among other things, (1) makes conforming amendments to our leverage and interest covenants, matching those in the First Lien Amendment, (2) establishes the Plans and defines “Permitted Capital Expenditures” in the same manner as the First Lien Amendment, and adds substantially similar requirements in connection with our development of the our drilling program within those Plans and substantially similar restrictions on our ability to engage in capital expenditures other than Permitted Capital Expenditures, (3) permits us to issue an additional $25,000 in preferred stock, measured in terms of the stated liquidation preference of that stock (as with the First Lien Amendment, to a total of $50,000 in stated liquidation preference in total), (4) adjusts the percentage by value of our oil and gas properties that must be the subject of mortgages in favor of the Second Lien Agent (for the benefit of the Second Lien Lenders) from 80% to 90%, (5) includes Mr. Carl F. Giesler, Jr., our Chief Executive Officer, as one of the officers designated in the definition of “Change of Control” under the Second Lien Credit Agreement, (6) eliminates restrictions on the sale of equity interests by Mr. Deloy Miller without impacting the “Change of Control” definition therein, (7) provides waivers related to certain events of default which arose as a result of Mr. Scott M. Boruff’s resignation as our Chief Executive Officer and certain sales of equity interests by Mr. Boruff as well as in connection with a scheduled payment of dividends on our preferred stock that occurred while an event of default had occurred; (8) extends the date by which the Company must remediate the material weakness in its internal controls over financial reporting from April 30, 2015 to April 30, 2016, (9) waives the requirement that the proceeds of the sale of (i) certain miscellaneous oil and gas equipment and office supplies in Tennessee or (ii) interests in the oil and gas properties of Savant, be applied to prepay the loans under the Second Lien Credit Agreement, so long as those proceeds are applied to certain projects specified in the Plans, (10) makes certain technical amendments intended to allow us to close the acquisition of Savant by easing certain requirements (which would have applied after that acquisition in the absence of this Second Lien Amendment) related to its subsidiary, Nutaaq Pipeline, LLC, (11) increases the interest rate applicable to loans under the Second Lien Credit Agreement by 1% per annum (or, if we elect to pay such interest in kind, by 2% per annum) until our Company has raised $20,000 in net proceeds from the issuance of equity interests of the Company, provided that if we have not raised such amounts within four months, the change in the interest rate becomes permanent and (12) adds additional Events of Default (as defined in the Second Lien Credit Agreement).
	Savant
	On May 8, 2014, we entered into an Agreement and Plan of Merger with Savant subject to due diligence and regulatory approval for $9,000. Savant currently owns, and we would acquire as a result of this merger, a 67.5% working interest in the Badami Unit and 100% ownership in certain nearby leases. ASRC Exploration, LLC owns the remaining 32.5% working interest in the Badami Unit. In addition to the working interest in the Badami Unit and the leases, we would acquire certain midstream assets located on the North Slope. We expect the transaction to close by December 2014, following regulatory approval. There is the potential that we may need to raise more capital through debt or equity to improve our liquidity to finance the merger.

Organization_and_Basis_of_Pres1

Organization and Basis of Presentation (Policies)	6 Months Ended
	Oct. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accompanying condensed consolidated financial statements are presented in accordance with GAAP and, in the opinion of management, include all adjustments (consisting only of normal recurring adjustments) necessary for a fair statement of the results for the interim periods. Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted under Securities and Exchange Commission ("SEC") rules and regulations. The results reported in these condensed consolidated financial statements are not necessarily indicative of the financial position or operating results that may be expected for the entire year.
	The financial information included herein should be read in conjunction with the audited consolidated financial statements and notes thereto included in Item 8 of Part II of the Company's Annual Report on Form 10-K for the year ended April 30, 2014, which was filed with the SEC on July 14, 2014, and amended on July 15, 2014.
	Certain amounts in prior fiscal years have been reclassified to conform with the presentation adopted in the current year.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Oct. 31, 2014
Accounting Policies [Abstract]	'
Principles of Consolidation	'
	Principles of Consolidation
	The accompanying condensed consolidated financial statements include our consolidated accounts after elimination of intercompany balances and transactions. The condensed consolidated financial statements also include the accounts of all investments in which we, either through direct or indirect ownership, have more than a 50% interest or significant influence over the management of those entities.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements requires us to utilize estimates and make judgments that affect the reported amounts of assets, liabilities, revenues and expenses and related disclosure of contingent assets and liabilities. These estimates are based on historical experience and on various other assumptions that we believe to be reasonable under the circumstances. The estimates are evaluated by management on an ongoing basis and the results of these evaluations form a basis for making decisions about the carrying value of assets and liabilities that are not readily apparent from other sources. Although actual results may differ from these estimates under different assumptions or conditions, we believe that the estimates used in the preparation of our financial statements are reasonable.
Oil and Gas Properties	'
	Oil and Gas Properties
	We follow the successful efforts method of accounting for oil and gas properties. Under this method, exploration costs, such as exploratory geological and geophysical costs, delay rentals and exploration overhead, are charged against earnings as incurred. Acquisition costs and costs of drilling exploratory wells are capitalized pending determination of whether proved reserves can be attributed to the area as a result of drilling the well. If management determines that commercial quantities of hydrocarbons have not been discovered, capitalized costs associated with exploratory wells are charged to exploration expense.
	Costs of drilling and equipping successful wells, costs to construct or acquire facilities, and associated asset retirement costs are depleted using the unit-of-production method based on total estimated proved developed reserves. Costs of acquiring proved properties, including leasehold acquisition costs transferred from unproved properties and costs to construct or acquire offshore platforms, and associated asset retirement costs are depleted using the unit-of-production method based on total estimated proved reserves.
	When circumstances indicate that proved properties may be impaired, the Company compares expected undiscounted future net cash flows, calculated using the Company's estimate of future oil and natural gas prices, operating expenses and production, to the net book value of the proved properties on a field by field basis. If the sum of the expected undiscounted future net cash flows is less than the net book value of the proved properties, an impairment loss is recognized for the excess, if any, of the net book value over its estimated fair value. See Note 6 for a discussion of asset impairments.
	Acquisition costs of unproved properties are assessed for impairment during the holding period and transferred to proved oil and gas properties to the extent the costs are associated with successful exploration activities. Significant undeveloped leases are assessed individually for impairment based on our current exploration plans, and a valuation allowance is provided if impairment is indicated. Costs of expired or abandoned leases are charged to expense, while costs of productive leases are transferred to proved oil and gas properties. Costs of maintaining and retaining unproved properties are included in oil and gas operating expense and impairments of unsuccessful leases are included in exploration expense.
Loss Per Share	'
	Loss Per Share
	We determine basic income (loss) per share and diluted income (loss) per share in accordance with the provisions of ASC 260, “Earnings Per Share.” Basic income (loss) per share excludes dilution and is computed by dividing earnings available to common stockholders by the weighted-average number of common shares outstanding for the period. The calculation of diluted earnings (loss) per share is similar to that of basic earnings per share, except that the denominator is increased, if net income is positive, to include the number of additional common shares that would have been outstanding if all potentially dilutive common shares, such as those issuable upon the exercise of stock options and warrants, had been exercised. We compute the numerator for basic income (loss) by subtracting accretion of preferred stock and cumulative preferred stock dividends from net income (loss) to arrive at net income (loss) attributable to common stockholders. Preferred stock dividends include dividends declared on preferred stock (regardless of whether the dividends have been paid) and dividends accumulated for the period on cumulative preferred stock (regardless of whether the dividends have been declared). As of October 31, 2014, our cumulative preferred dividends were $6,406.
Deferred Escalating Minimum Rent	'
	Deferred Escalating Minimum Rent
	Certain of our operating leases contain predetermined fixed escalations of the minimum rentals during the term of the lease, which includes option periods where failure to exercise such options would result in an economic penalty. For these leases, we recognize the related rental expense on a straight-line basis over the life of the lease, beginning with the point at which we obtain control and possession of the leased properties, and record the difference between the amounts charged to operations and amounts paid as deferred escalating minimum rent. Any lease incentives received are deferred and subsequently amortized on a straight-line basis over the life of the lease as a reduction to rent expense.
New Accounting Pronouncements Issued	'
	New Accounting Pronouncements Issued But Not Yet Adopted
	In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers (Topic 606)." ASU 2014-09 is intended to improve the financial reporting requirements for revenue from contracts with customers by providing a principle based approach. The core principle of the standard is that revenue should be recognized when the transfer of promised goods or services is made in an amount that the entity expects to be entitled to in exchange for the transfer of goods and services. ASU 2014-09 also requires disclosures enabling users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. This standard will be effective for financial statements issued by public companies for annual reporting periods beginning after December 15, 2016. Early adoption is not permitted. The Company is currently evaluating the potential impact of ASU 2014-09 on the condensed consolidated financial statements.
	In August 2014, the FASB issued ASU 2014-15, "Presentation of Financial Statements - Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern" that describes how an entity's management should assess whether there are conditions and events that raise substantial doubt about an entity's ability to continue as a going concern within one year after the date that the financial statements are issued. Management should consider both quantitative and qualitative factors in making its assessment. The new standard applies to all entities for the first annual period ending after December 15, 2016, and for annual and interim periods thereafter. Early application is permitted. The Company will assess the potential impact of ASU 2014-15 when applicable circumstances are present.
	New Accounting Pronouncements Issued and Adopted
	In April 2014, the FASB issued ASU 2014-08, "Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity." ASU 2014-08 changes the definition of a discontinued operation to include only those disposals of components of an entity that represent a strategic shift that has (or will have) a major effect on an entity's operations and financial results. In addition, ASU 2014-08 requires additional disclosures about both discontinued operations and the disposal of an individually significant component of an entity that does not qualify for discontinued operations presentation in the financial statements. The guidance is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2014, with early adoption permitted. We adopted the provisions of ASU 2014-08 on a prospective basis during the first quarter of fiscal year 2015. The adoption of this ASU did not have an impact on our condensed consolidated financial statements.
	There are no other recently issued accounting pronouncements that are expected to have a material impact on our financial condition, results of operations or cash flows.

Acquisitions_Tables

Acquisitions (Tables)	6 Months Ended
	Oct. 31, 2014
Business Combinations [Abstract]	'
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	'
	The following table summarizes the consideration paid for the Anchor Point Pipeline and the allocation of the purchase price to the assets acquired and liabilities assumed that have been included in the Company's condensed consolidated financial statements. The Company is in the process of finalizing the evaluation of the assigned fair values to the assets acquired and liabilities assumed.
	Purchase Price:
	Series D Preferred Stock	$	5,446
	Preliminary Allocation of Assets Acquired and Liabilities Assumed:
	Natural gas pipeline and pipeline support assets	$	5,687
	Asset retirement obligation	$	(241	)
	Fair value of assets acquired and liabilities assumed	$	5,446

Oil_and_Gas_Properties_and_Equ1

Oil and Gas Properties and Equipment (Tables)	6 Months Ended
	Oct. 31, 2014
Property, Plant and Equipment [Abstract]	'
Capitalized Costs Relating to Oil and Gas Producing Activities Disclosure	'
	Oil and gas properties (successful efforts method) are summarized as follows:
		October 31,			April 30,
		2014			2014
	Property costs:
	Proved property	$	479,911		$	467,740
	Unproved property	93,498			243,230
	Total property costs	573,409			710,970
	Less: Accumulated depletion	(210,854		)	(66,143		)
	Oil and gas properties, net	$	362,555		$	644,827
Property, Plant and Equipment	'
	Equipment is summarized as follows:
		October 31,			April 30,
		2014			2014
	Machinery and equipment	$	5,997		$	7,759
	Vehicles	512			1,877
	Buildings	2,447			2,726
	Office equipment	1,180			1,108
	Leasehold improvements	677			527
	Drilling rigs	43,640			30,210
	Capital lease asset	3,678			1,500
	Natural gas pipeline and pipeline support assets	5,687			—
		63,818			45,707
	Less: Accumulated depreciation	(9,588		)	(10,338		)
	Equipment, net	$	54,230		$	35,369
Depreciation, Depletion, and Amortization	'
	Depreciation, depletion and amortization consisted of the following:
		For the Six Months Ended October 31,
		2014			2013
	Depletion of oil and gas related assets	$	35,026		$	12,532
	Depreciation and amortization of equipment	2,034			2,178
	Total	$	37,060		$	14,710

Derivative_Instruments_Tables

Derivative Instruments (Tables)	6 Months Ended
	Oct. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of Derivative Instruments	'
	As of October 31, 2014, we had the following open crude oil derivative positions. All are priced based on the Brent crude oil futures as traded on the Intercontinental Exchange.
			Fixed - Price Swaps
	Production Period ending April 30,		Bbls			Weighted Average Fixed Price
	2015		389,600			98.71
	2016		787,600			95.36
	2017		232,600			93.97
Schedule of Derivative Liabilities at Fair Value	'
	The following table presents the fair value of commodity derivatives. The fair value amounts are presented on a gross basis and do not reflect the netting of asset and liability positions permitted under the terms of our master netting arrangements.
			Asset Derivatives											Liability Derivatives
			October 31, 2014						April 30, 2014					October 31, 2014				April 30, 2014
	Derivatives not designated as hedging instruments under ASC 815		Balance Sheet Location		Fair Value				Balance Sheet Location		Fair Value			Balance Sheet Location		Fair Value		Balance Sheet Location	Fair Value
	Commodity derivatives		Prepaid expenses and other		$	7,222			Prepaid expenses and other		$	88		Current portion of derivative instruments		$	—	Current portion of derivative instruments	$	(3,315	)
	Commodity derivatives		Other assets		2,159				Other assets		26			Long-term portion of derivative instruments		—		Long-term portion of derivative instruments	(4,006		)
	Total derivatives not designated as hedging instruments under ASC 815				$	9,381					$	114				$	—		$	(7,321	)
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	'
	The following table presents our gross and net derivative assets and liabilities:
		Gross Amount Presented on Balance Sheet				Netting Adjustments (a)				Net Amount
	October 31, 2014
	Derivative assets with right of offset or master netting agreements	$	9,381			$	—			$	9,381
	April 30, 2014
	Derivative assets with right of offset or master netting agreements	$	114			$	(114	)		$	—
	Derivative liabilities with right of offset or master netting agreements	$	(7,321	)		$	114			$	(7,207	)
	—————————
	(a)	The Company has an agreement in place that allows for the financial right of offset for derivative assets and derivative liabilities at settlement or in the event of default under the agreement.
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	'
	Gains and losses on derivatives are reported in the condensed consolidated statements of operations. The following represents the Company's reported gains and losses on derivative instruments for the periods presented:
		For the Three Months Ended October 31,								For the Six Months Ended October 31,
		2014				2013				2014			2013
	Gain (loss) on derivatives, net	$	23,089			$	(4,190	)		$	16,186		$	(7,266	)

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Oct. 31, 2014
Fair Value Disclosures [Abstract]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	'
	The following summarizes the fair value of the Company's commodity derivative assets and liabilities according to their fair value hierarchy as of the reporting dates indicated:
		Fair Value Measurements
	At October 31, 2014	Level 1		Level 2			Level 3
	Commodity derivative asset	$	—	$	9,381		$	—
	Total	$	—	$	9,381		$	—
	At April 30, 2014
	Commodity derivative asset	$	—	$	114		$	—
	Commodity derivative liability	—		(7,321		)	—
	Total	$	—	$	(7,207	)	$	—

Debt_Tables

Debt (Tables)	6 Months Ended
	Oct. 31, 2014
Debt Disclosure [Abstract]	'
Schedule of Long-term Debt Instruments	'
	As of October 31, 2014 and April 30, 2014, we had the following debt obligations:
		October 31,				April 30,
		2014				2014
	Second Lien Credit Facility	$	175,000			$	175,000
	Debt discount related to Second Lien Credit Facility	(2,858		)		(3,296		)
	First Lien RBL	36,000				—
	Gunsight Promissory Note payable	950				950
	Apollo prepayment and extension fee note payable	4,612				9,223
	Capital lease obligation	2,951				—
	Series B Preferred Stock	2,363				2,325
	Total debt obligations	219,018				184,202
	Less: Current maturities	(6,095		)		(9,459		)
	Total debt less current maturities	$	212,923			$	174,743
Schedule of Line of Credit Facilities Borrowing Base Utilization	'
	Amounts outstanding under the First Lien RBL are priced on a sliding scale, based on LIBOR plus 300 to 400 basis points, depending upon the level of borrowing (per the table below).
	Borrowing Base Utilization Grid
	Borrowing base utilization percentage	<25%	≥ 25%, but <50%	≥ 50%, but <75%	≥ 75%, but <90%	≥ 90%, but ≤100%
	Spread above LIBOR	3.00%	3.25%	3.50%	3.75%	4.00%
	Undrawn commitment fee rate	0.50%	0.50%	0.75%	0.75%	0.75%

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	6 Months Ended
	Oct. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]	'
Schedule of Asset Retirement Obligations	'
	The following table presents changes to the Company's asset retirement obligation ("ARO") liability for the six months ended October 31, 2014 and 2013:
		2014			2013
	Asset retirement obligation, as of April 30,	$	22,872		$	19,890
	Additions, including Anchor Point Pipeline	262			—
	Revisions	(99		)	—
	Accretion expense	697			598
	Settlements	(121		)	(16		)
	North Fork properties purchase price adjustment	159			—
	Asset retirement obligation, as of October 31,	$	23,770		$	20,472
	Less: Asset retirement obligation related to assets held for sale	(1,494		)	—
	Revised asset retirement obligation, as of October 31,	$	22,276		$	20,472

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	6 Months Ended
	Oct. 31, 2014
Share-based Compensation [Abstract]	'
Schedule of Share-based Compensation, Activity	'
	The following table summarizes stock options and warrants activity for the period presented:
		Number of Options and Warrants		Weighted Average Exercise Price
	Beginning balance at April 30, 2014	15,021,347		$	4.99
	Granted	2,670,500		4.59
	Exercised	(321,354	)	4.44
	Cancelled	(386,512	)	5.14
	Ending balance	16,983,981		4.93
	Options and warrants exercisable at October 31, 2014	13,376,916		$	4.87
Schedule of Share-based Compensation, Shares and Warrants Authorized under Stock Option Plans, by Exercise Price Rance	'
	The following table summarizes stock options and warrants outstanding, including exercisable shares at October 31, 2014:
	Options and Warrants Outstanding							Options and Warrants
								Exercisable
	Range of Exercise Price		Number Outstanding		Weighted Average Remaining Contractual Life (in years)	Weighted Average Exercise Price		Number Exercisable	Weighted Average Exercise Price
	$0.01 to $1.82		1,480,200		0.7	$	0.7	1,480,200	$	0.7
	$2.00 to $4.99		3,886,334		7.4	4.04		2,199,769	3.76
	$5.15 to $5.53		4,137,447		2.5	5.32		3,641,947	5.33
	$5.68 to $5.94		3,535,000		6.1	5.91		3,295,000	5.92
	$6.00 to $6.95		3,945,000		3.1	6.13		2,760,000	6.15
			16,983,981		4.3	$	4.93	13,376,916	$	4.87
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	'
	The following table summarizes restricted stock activity for the six months ended October 31, 2014:
	Unvested at April 30, 2014	465,432
	Granted	930,655
	Vested	(1,139,754	)
	Cancelled	(25,000	)
	Unvested at October 31, 2014	231,333

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	6 Months Ended
	Oct. 31, 2014
Stockholders' Equity Note [Abstract]	'
Dividends Declared	'
	The following table summarizes the Series C Preferred Stock and Series D Preferred Stock dividend activity for the six months ended October 31, 2014.
	Series	Declaration Date	Dividend per Share		Annualized Percentage Rate		Par Value		Accrual Period	Record Date	Payment Date
	C	July 28, 2014	$	0.67	10.75	%	$	25	Jun. 1 - Aug. 31, 2014	August 15, 2014	September 2, 2014
	D	July 28, 2014	$	0.66	10.5	%	$	25	Jun. 1 - Aug. 31, 2014	August 15, 2014	September 2, 2014
	C	October 29, 2014	$	0.67	10.75	%	$	25	Sept. 1 - Nov. 30, 2014	November 14, 2014	December 1, 2014
	D	October 29, 2014	$	0.66	10.5	%	$	25	Sept. 1 - Nov. 30, 2014	November 14, 2014	December 1, 2014
	The following table summarizes the Series C Preferred Stock and Series D Preferred Stock dividend activity subsequent to October 31, 2014.
	Series	Declaration Date	Dividend Paid per Share		Annualized Percentage Rate		Par Value		Accrual Period	Record Date	Payment Date
	C	29-Oct-14	$	0.67	10.75	%	$	25	Sept. 1 - Nov. 30, 2014	14-Nov-14	1-Dec-14
	D	29-Oct-14	$	0.66	10.5	%	$	25	Sept. 1 - Nov. 30, 2014	14-Nov-14	1-Dec-14

Alaska_Production_Credits_Tabl

Alaska Production Credits (Tables)	6 Months Ended
	Oct. 31, 2014
Alaska Production Credits [Abstract]	'
Allowance for Credit Losses on Financing Receivables	'
	We did not incur any Alaska production taxes in fiscal 2014, 2013 or 2012, and accordingly, the carried-forward annual loss credits are presented separately in our operating expenses on the condensed consolidated statements of operations.
	Balance, April 30, 2014	$	49,121
	Alaska carried-forward annual loss credits, net 1	2,732
	Applications for expenditure and exploration based credits 1	41,843
	Cash collections for expenditure and exploration based credits	(56,012		)
	Balance, October 31, 2014	$	37,684
	———————————
	1	Applications for carried-forward annual loss credits and for expenditure and exploration based credits are recorded net of established reserves and also include revisions to prior period applications, if applicable.

Subsequent_Events_Tables

Subsequent Events (Tables)	6 Months Ended
	Oct. 31, 2014
Subsequent Events [Abstract]	'
Dividends Declared	'
	The following table summarizes the Series C Preferred Stock and Series D Preferred Stock dividend activity for the six months ended October 31, 2014.
	Series	Declaration Date	Dividend per Share		Annualized Percentage Rate		Par Value		Accrual Period	Record Date	Payment Date
	C	July 28, 2014	$	0.67	10.75	%	$	25	Jun. 1 - Aug. 31, 2014	August 15, 2014	September 2, 2014
	D	July 28, 2014	$	0.66	10.5	%	$	25	Jun. 1 - Aug. 31, 2014	August 15, 2014	September 2, 2014
	C	October 29, 2014	$	0.67	10.75	%	$	25	Sept. 1 - Nov. 30, 2014	November 14, 2014	December 1, 2014
	D	October 29, 2014	$	0.66	10.5	%	$	25	Sept. 1 - Nov. 30, 2014	November 14, 2014	December 1, 2014
	The following table summarizes the Series C Preferred Stock and Series D Preferred Stock dividend activity subsequent to October 31, 2014.
	Series	Declaration Date	Dividend Paid per Share		Annualized Percentage Rate		Par Value		Accrual Period	Record Date	Payment Date
	C	29-Oct-14	$	0.67	10.75	%	$	25	Sept. 1 - Nov. 30, 2014	14-Nov-14	1-Dec-14
	D	29-Oct-14	$	0.66	10.5	%	$	25	Sept. 1 - Nov. 30, 2014	14-Nov-14	1-Dec-14

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details) (USD $)	Oct. 31, 2014
In Thousands, unless otherwise specified
Accounting Policies [Abstract]	'
Cumulative dividends	$6,406

Acquisitions_Details

Acquisitions (Details) (Anchor Point Pipeline [Member], USD $)	0 Months Ended
In Thousands, unless otherwise specified	Aug. 08, 2014
Preliminary Allocation of Assets Acquired and Liabilities Assumed:	'
Natural gas pipeline and pipeline support assets	$5,687
Asset retirement obligation	-241
Fair value of assets acquired and liabilities assumed	5,446
Series D Preferred Stock [Member]	'
Purchase Price:	'
Series D Preferred Stock	$5,446

Acquisitions_Details_Textual

Acquisitions (Details Textual) (Scenario, Forecast [Member], Savant Alaska, LLC [Member], USD $)	0 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2014
	gal	airstrip
	bbl	tank
	mi	Pipeline
	MW	bbl
	airstrip	Well
	tank	facility
	Pipeline
	Well
	facility
Scenario, Forecast [Member] | Savant Alaska, LLC [Member]	'	'
Business Acquisition [Line Items]	'	'
Acquisition cost	$9,000	'
Working interest acquired (percent)	'	67.50%
Ownership in nearby leases (percent)	'	100.00%
ASRC Exploration, LLC working interest ownership (percent)	'	32.50%
Daily processing capacity (in barrels per day)	'	38,500
Number of diesel storage tanks	'	1
Diesel storage tank holding capacity (in gallons)	500,000	'
Power generation (in megawatts)	20	'
Number of grind and inject solid waste disposal facilities	'	1
Number of Class 1 disposal wells	'	1
Number of airstrips	'	1
Airstrip length (in miles)	1	'
Number of pipelines	'	2
Length per pipeline (in miles)	25	'
Gross BOPD production (in barrels per day)	1,100	'
Net BOPD production (in barrels per day)	600	'

Acquisitions_Details_Textual_1

Acquisitions (Details Textual 1) (Anchor Point Pipeline [Member], USD $)	Oct. 31, 2014	Aug. 08, 2014
In Thousands, unless otherwise specified		Series D Preferred Stock [Member]
Business Acquisition [Line Items]	'	'
Series D Preferred Stock purchase consideration	'	$5,446
Goodwill	$0	'

Major_Customers_and_Concentrat1

Major Customers and Concentrations of Credit Risk (Details) (USD $)

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

Oct. 31, 2014

Oct. 31, 2013

Oct. 31, 2014

Oct. 31, 2013

Oct. 31, 2014

Oct. 31, 2014

Oct. 31, 2014

Apr. 30, 2014

Oct. 31, 2014

Oct. 31, 2014

Oct. 31, 2014

Apr. 30, 2014

Customer One [Member]

Customer One [Member]

Customer One [Member]

Customer One [Member]

Customer Two [Member]

Customer Two [Member]

Customer Two [Member]

Customer Two [Member]

Revenue [Member]

Revenue [Member]

Accounts receivable [Member]

Accounts receivable [Member]

Revenue [Member]

Revenue [Member]

Accounts receivable [Member]

Accounts receivable [Member]

Concentration Risk [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Concentration risk (percent)

'

'

'

'

83.00%

82.00%

11.00%

5.00%

15.00%

14.00%

19.00%

23.00%

Credit losses

'

$0

$0

$0

'

'

'

'

'

'

'

'

FDIC uninsured amount

14,217,000

'

14,217,000

'

'

'

'

'

'

'

'

'

FDIC insured amount

$250,000

'

$250,000

'

'

'

'

'

'

'

'

'

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	3 Months Ended	6 Months Ended		0 Months Ended
In Thousands, except Share data, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2014	Dec. 09, 2014	Dec. 09, 2014
	Immediate Family Member of Management or Principal Owner [Member]	Immediate Family Member of Management or Principal Owner [Member]	Subsequent Event [Member]	Subsequent Event [Member]
				Affiliated Entity [Member]
Related Party Transaction [Line Items]	'	'	'	'
Amount paid to related party	$985	$1,703	'	'
Annual compensation	'	'	'	$275
Shares issued (in shares)	'	'	'	100,000
Exercise price (in dollars per share)	'	'	$1.35	'

Oil_and_Gas_Properties_and_Equ2

Oil and Gas Properties and Equipment (Details) (USD $)	Oct. 31, 2014	Apr. 30, 2014
In Thousands, unless otherwise specified
Property costs:	'	'
Proved property	$479,911	$467,740
Unproved property	93,498	243,230
Total property costs	573,409	710,970
Less: Accumulated depletion	-210,854	-66,143
Oil and gas properties, net	$362,555	$644,827

Oil_and_Gas_Properties_and_Equ3

Oil and Gas Properties and Equipment (Details 1) (USD $)	Oct. 31, 2014	Apr. 30, 2014
In Thousands, unless otherwise specified
Equipment	'	'
Equipment, gross	$63,818	$45,707
Less: Accumulated depreciation	-9,588	-10,338
Equipment, net	54,230	35,369
Machinery and Equipment [Member]	'	'
Equipment	'	'
Equipment, gross	5,997	7,759
Vehicles [Member]	'	'
Equipment	'	'
Equipment, gross	512	1,877
Buildings [Member]	'	'
Equipment	'	'
Equipment, gross	2,447	2,726
Office Equipment [Member]	'	'
Equipment	'	'
Equipment, gross	1,180	1,108
Leasehold Improvements [Member]	'	'
Equipment	'	'
Equipment, gross	677	527
Drilling Rigs [Member]	'	'
Equipment	'	'
Equipment, gross	43,640	30,210
Capital Lease Asset [Member]	'	'
Equipment	'	'
Equipment, gross	3,678	1,500
Natural Gas Pipeline and Pipeline Support Assets [Member]	'	'
Equipment	'	'
Equipment, gross	$5,687	$0

Oil_and_Gas_Properties_and_Equ4

Oil and Gas Properties and Equipment (Details 2) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013
Property, Plant and Equipment [Abstract]	'	'
Depletion of oil and gas related assets	$35,026	$12,532
Depreciation and amortization of equipment	2,034	2,178
Total	$37,060	$14,710

Oil_and_Gas_Properties_and_Equ5

Oil and Gas Properties and Equipment (Details Textual) (USD $)	6 Months Ended		3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2014	Oct. 31, 2014	Oct. 31, 2014	Oct. 31, 2014	Oct. 31, 2014
			Redoubt Unit [Member]	Redoubt Unit [Member]	Olsen Creek No. 2 [Member]	Rig 37 [Member]	Rig 36 [Member]	Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
			Oil and Gas Properties [Member]	Fair Value, Measurements, Nonrecurring [Member]	Oil and Gas Properties [Member]	Oil and Gas Properties [Member]		Tennessee Divestiture [Member]
				Fair Value, Inputs, Level 3 [Member]
				Oil and Gas Properties [Member]
Property, Plant and Equipment [Line Items]	'	'	'	'	'	'	'	'
Impairment of unproved properties	'	'	$112,414	'	'	'	'	'
Impairment of proved properties	'	'	152,887	'	'	'	'	'
Fair value	'	'	'	122,587	'	'	'	'
Non-cash exploration expenses	166,303	193	'	'	13,325	'	'	'
Fair value of Tennessee assets	'	'	'	'	'	'	'	5,072
Liabilities	'	'	'	'	'	'	'	1,495
Cost to sell Tennessee assets	'	'	'	'	'	'	'	246
Impairment charge	'	'	'	'	'	'	'	1,319
Payment for rig	'	'	'	'	'	6,346	'	'
Future contingent payment for rig	'	'	'	'	'	654	'	'
Capital lease obligation	$3,250	'	'	'	'	'	$3,250	'

Derivative_Instruments_Details

Derivative Instruments (Details) (Not Designated as Hedging Instrument [Member], Crude Oil [Member], Swap [Member])	6 Months Ended
	Oct. 31, 2014
	bbl
2015 [Member]	'
Derivative [Line Items]	'
Open positions (in barrels)	389,600
Weighted average fixed price (in dollars per barrel)	98.71
2016 [Member]	'
Derivative [Line Items]	'
Open positions (in barrels)	787,600
Weighted average fixed price (in dollars per barrel)	95.36
2017 [Member]	'
Derivative [Line Items]	'
Open positions (in barrels)	232,600
Weighted average fixed price (in dollars per barrel)	93.97

Derivative_Instruments_Details1

Derivative Instruments (Details 1) (Not Designated as Hedging Instrument [Member], Commodity Contract [Member], USD $)	Oct. 31, 2014	Apr. 30, 2014
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Commodity derivative asset	$9,381	$114
Commodity derivative liability	0	7,321
Prepaid Expenses and Other [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Commodity derivative asset	7,222	88
Other Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Commodity derivative asset	2,159	26
Current Portion of Derivative Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Commodity derivative liability	'	3,315
Long-term Portion of Derivative Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Commodity derivative liability	'	$4,006

Derivative_Instruments_Details2

Derivative Instruments (Details 2) (Not Designated as Hedging Instrument [Member], Commodity Contract [Member], USD $)	Oct. 31, 2014		Apr. 30, 2014
In Thousands, unless otherwise specified
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member]	'		'
Derivatives, Fair Value [Line Items]	'		'
Gross derivative assets presented on balance sheet	$9,381		$114
Netting adjustments	0	[1]	-114	[1]
Net derivative assets	9,381		0
Gross derivative liabilities presented on balance sheet	0		-7,321
Netting adjustments	'		114	[1]
Net derivative liabilities	'		($7,207)
[1]	The Company has an agreement in place that allows for the financial right of offset for derivative assets and derivative liabilities at settlement or in the event of default under the agreement.

Derivative_Instruments_Details3

Derivative Instruments (Details 3) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'	'	'	'
Gain (loss) on derivatives, net	$23,089	($4,190)	$16,186	($7,266)

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (Commodity Contract [Member], Not Designated as Hedging Instrument [Member], USD $)	Oct. 31, 2014	Apr. 30, 2014
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Commodity derivative asset	$9,381	$114
Commodity derivative liability	0	-7,321
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Commodity derivative asset	9,381	114
Commodity derivative liability	'	-7,321
Total	$9,381	($7,207)

Debt_Details

Debt (Details) (USD $)	Oct. 31, 2014	Apr. 30, 2014
Long-term Debt, Excluding Current Maturities [Abstract]	'	'
Gunsight Promissory Note payable	$950,000	$950,000
Capital lease obligation	2,951,000	0
Series B Preferred Stock	2,363,000	2,325,000
Total debt obligations	219,018,000	184,202,000
Less: Current maturities	-6,095,000	-9,459,000
Total debt less current maturities	212,923,000	174,743,000
Second Lien Credit Facility [Member]	'	'
Long-term Debt, Excluding Current Maturities [Abstract]	'	'
Credit facility amount	175,000,000	175,000,000
Debt discount	-2,858,000	-3,296,000
First Lien RBL [Member]	'	'
Long-term Debt, Excluding Current Maturities [Abstract]	'	'
Credit facility amount	36,000,000	0
Apollo Senior Secured Credit Facility [Member]	'	'
Long-term Debt, Excluding Current Maturities [Abstract]	'	'
Prepayment and extension fee note payable	$4,612,000	$9,223,000

Debt_Details_1

Debt (Details 1) (London Interbank Offered Rate (LIBOR) [Member], First Lien RBL [Member])	6 Months Ended
	Oct. 31, 2014
Range 1 [Member]	'
Line of Credit Facility [Line Items]	'
Spread above LIBOR (percent)	3.00%
Undrawn commitment fee rate (percent)	0.50%
Range 2 [Member]	'
Line of Credit Facility [Line Items]	'
Spread above LIBOR (percent)	3.25%
Undrawn commitment fee rate (percent)	0.50%
Range 3 [Member]	'
Line of Credit Facility [Line Items]	'
Spread above LIBOR (percent)	3.50%
Undrawn commitment fee rate (percent)	0.75%
Range 4 [Member]	'
Line of Credit Facility [Line Items]	'
Spread above LIBOR (percent)	3.75%
Undrawn commitment fee rate (percent)	0.75%
Range 5 [Member]	'
Line of Credit Facility [Line Items]	'
Spread above LIBOR (percent)	4.00%
Undrawn commitment fee rate (percent)	0.75%

Debt_Details_2

Debt (Details 2) (First Lien RBL [Member])	6 Months Ended
	Oct. 31, 2014
Range 1 [Member]	'
Line of Credit Facility [Line Items]	'
Lower range of borrowing base utilization (percent)	0.00%
Higher range of borrowing base utilization (percent)	24.00%
Range 2 [Member]	'
Line of Credit Facility [Line Items]	'
Lower range of borrowing base utilization (percent)	25.00%
Higher range of borrowing base utilization (percent)	49.00%
Range 3 [Member]	'
Line of Credit Facility [Line Items]	'
Lower range of borrowing base utilization (percent)	50.00%
Higher range of borrowing base utilization (percent)	74.00%
Range 4 [Member]	'
Line of Credit Facility [Line Items]	'
Lower range of borrowing base utilization (percent)	75.00%
Higher range of borrowing base utilization (percent)	89.00%
Range 5 [Member]	'
Line of Credit Facility [Line Items]	'
Lower range of borrowing base utilization (percent)	90.00%
Higher range of borrowing base utilization (percent)	100.00%

Debt_Details_Textual

Debt (Details Textual) (USD $)

Oct. 31, 2014

Apr. 30, 2014

Feb. 03, 2014

Jun. 29, 2012

Feb. 03, 2014

Nov. 22, 2013

Feb. 03, 2014

Feb. 03, 2014

Aug. 02, 2014

Jun. 24, 2014

Jun. 02, 2014

Oct. 31, 2014

Jun. 02, 2014

Oct. 31, 2014

Apr. 30, 2014

Prior Credit Facility [Member]

Prior Credit Facility [Member]

Second Lien Credit Facility [Member]

Second Lien Credit Facility [Member]

Second Lien Credit Facility [Member]

Second Lien Credit Facility [Member]

First Lien RBL [Member]

First Lien RBL [Member]

First Lien RBL [Member]

First Lien RBL [Member]

First Lien RBL [Member]

Fair Value, Inputs, Level 3 [Member]

Fair Value, Inputs, Level 3 [Member]

London Interbank Offered Rate (LIBOR) [Member]

Second Lien Credit Facility [Member]

Second Lien Credit Facility [Member]

Line of Credit Facility [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility

'

'

'

$100,000,000

'

'

$175,000,000

'

'

'

'

'

'

'

'

Borrowing base

'

'

'

'

'

'

175,000,000

'

'

'

'

'

60,000,000

'

'

Amount borrowed

'

'

'

'

175,000,000

'

'

'

16,000,000

10,000,000

20,000,000

'

'

'

'

Original issue discount (percent)

'

'

'

'

'

'

2.00%

'

'

'

'

'

1.00%

'

'

Variable rate (percent)

'

'

'

'

'

'

'

9.75%

'

'

'

'

'

'

'

LIBOR floor rate (percent)

'

'

'

'

'

'

'

2.00%

'

'

'

'

'

'

'

Revolving credit facility

'

'

'

'

'

'

100,000,000

'

'

'

'

'

250,000,000

'

'

Maturity (in years)

'

'

'

'

'4 years

'

'

'

'

'

'

'

'

'

'

Repayments on lines of credit

'

'

75,306,000

'

'

'

'

'

'

'

'

10,000,000

'

'

'

Amount used to finance acquisition costs

'

'

'

'

'

56,577,000

'

'

'

'

'

'

'

'

'

Amount used to retire notes payable obligation

'

'

'

'

3,071,000

'

'

'

'

'

'

'

'

'

'

Fair value of outstanding balance

'

'

'

'

'

'

'

'

'

'

'

'

'

171,781,000

176,785,000

Unamortized deferred financing costs

$2,385,000

$803,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt_Details_Textual_1

Debt (Details Textual 1) (Cumulative Preferred Stock Subject to Mandatory Redemption [Member], Series B Preferred Stock [Member], USD $)	0 Months Ended	6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 02, 2014	Oct. 31, 2014	Oct. 31, 2014	Apr. 30, 2014
			Fair Value, Inputs, Level 2 [Member]	Fair Value, Inputs, Level 2 [Member]
Preferred Stock	'	'	'	'
Fair value	'	'	$2,075	$2,197
Semiannual dividend paid (in dollars per share)	$6.05	'	'	'
Cumulative dividend rate per annum (percent)	'	12.00%	'	'
Liquidation preference (in dollars per share)	'	$100	'	'

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013	Apr. 30, 2014
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]	'	'	'	'	'
Asset retirement obligation, as of April 30,	'	'	$22,872	$19,890	'
Additions, including Anchor Point Pipeline	'	'	262	'	'
Revisions	'	'	-99	0	'
Accretion expense	351	301	697	598	'
Settlements	'	'	-121	-16	'
North Fork properties purchase price adjustment	'	'	159	0	'
Asset retirement obligation, as of October 31,	23,770	20,472	23,770	20,472	'
Less: Asset retirement obligation related to assets held for sale	-1,494	0	-1,494	0	'
Revised asset retirement obligation, as of October 31,	$22,276	$20,472	$22,276	$20,472	$22,872

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	6 Months Ended
	Oct. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'
Beginning balance at April 30, 2014 (in shares)	15,021,347
Beginning balance at April 30, 2014, weighted average exercise price (in dollars per share)	$4.99
Granted (in shares)	2,670,500
Granted, weighted average price (in dollars per share)	$4.59
Exercised (in shares)	-321,354
Exercised, weighted average price (in dollars per share)	$4.44
Cancelled (in shares)	-386,512
Cancelled, weighted average price (in dollars per share)	$5.14
Ending balance (in shares)	16,983,981
Ending balance, weighted average exercise price (in dollars per share)	$4.93
Options and warrants exercisable at October 31, 2014 (in shares)	13,376,916
Options and warrants exercisable at October 31, 2014, weighted average price (in dollars per share)	$4.87

StockBased_Compensation_Detail1

Stock-Based Compensation (Details 1) (USD $)	6 Months Ended
	Oct. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	16,983,981
Weighted average remaining contractural life (in years)	'4 years 3 months 18 days
Weighted average exercise price (in dollars per share)	$4.93
Number exercisable (in shares)	13,376,916
Weighted average exercise price (in dollars per share)	$4.87
$0.01 to $1.82 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	1,480,200
Weighted average remaining contractural life (in years)	'0 years 8 months 12 days
Weighted average exercise price (in dollars per share)	$0.70
Number exercisable (in shares)	1,480,200
Weighted average exercise price (in dollars per share)	$0.70
$2.00 to $4.99 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	3,886,334
Weighted average remaining contractural life (in years)	'7 years 4 months 24 days
Weighted average exercise price (in dollars per share)	$4.04
Number exercisable (in shares)	2,199,769
Weighted average exercise price (in dollars per share)	$3.76
$5.15 to $5.53 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	4,137,447
Weighted average remaining contractural life (in years)	'2 years 6 months
Weighted average exercise price (in dollars per share)	$5.32
Number exercisable (in shares)	3,641,947
Weighted average exercise price (in dollars per share)	$5.33
$5.68 to $5.94 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	3,535,000
Weighted average remaining contractural life (in years)	'6 years 1 month 6 days
Weighted average exercise price (in dollars per share)	$5.91
Number exercisable (in shares)	3,295,000
Weighted average exercise price (in dollars per share)	$5.92
$6.00 to $6.95 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	3,945,000
Weighted average remaining contractural life (in years)	'3 years 1 month 6 days
Weighted average exercise price (in dollars per share)	$6.13
Number exercisable (in shares)	2,760,000
Weighted average exercise price (in dollars per share)	$6.15

StockBased_Compensation_Detail2

Stock-Based Compensation (Details 2) (USD $)	6 Months Ended
	Oct. 31, 2014
$0.01 to $1.82 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise price range, lower limit (in dollars per share)	$0.01
Exercise price range, upper limit (in dollars per share)	$1.82
$2.00 to $4.99 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise price range, lower limit (in dollars per share)	$2
Exercise price range, upper limit (in dollars per share)	$4.99
$5.15 to $5.53 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise price range, lower limit (in dollars per share)	$5.15
Exercise price range, upper limit (in dollars per share)	$5.53
$5.68 to $5.94 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise price range, lower limit (in dollars per share)	$5.68
Exercise price range, upper limit (in dollars per share)	$5.94
$6.00 to $6.95 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise price range, lower limit (in dollars per share)	$6
Exercise price range, upper limit (in dollars per share)	$6.95

StockBased_Compensation_Detail3

Stock-Based Compensation (Details 3)	6 Months Ended
	Oct. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]	'
Unvested at April 30, 2014 (in shares)	465,432
Granted (in shares)	930,655
Vested (in shares)	-1,139,754
Cancelled (in shares)	-25,000
Unvested at October, 2014 (in shares)	231,333

StockBased_Compensation_Detail4

Stock-Based Compensation (Details Textual) (USD $)

3 Months Ended

6 Months Ended

0 Months Ended

In Thousands, except Share data, unless otherwise specified

Oct. 31, 2014

Oct. 31, 2013

Oct. 31, 2014

Oct. 31, 2013

Oct. 31, 2014

Apr. 30, 2014

Apr. 30, 2010

Oct. 30, 2014

Apr. 16, 2014

Oct. 31, 2014

Apr. 30, 2014

Apr. 30, 2011

2010 Stock Incentive Plan [Member]

2010 Stock Incentive Plan [Member]

2010 Stock Incentive Plan [Member]

2011 Stock Incentive Plan [Member]

2011 Stock Incentive Plan [Member]

2011 Stock Incentive Plan [Member]

2011 Stock Incentive Plan [Member]

2011 Stock Incentive Plan [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Shares authorized (in shares)

'

'

'

'

'

'

3,000,000

'

'

'

'

8,250,000

Additional shares authorized (in shares)

'

'

'

'

'

'

'

2,500,000

5,000,000

'

'

'

Shares available for grant (in shares)

'

'

'

'

59,166

2,500

'

'

'

2,483,423

3,132,078

'

Employee share-based compensation expense

$7,414

$1,469

$9,059

$3,025

'

'

'

'

'

'

'

'

Nonemployee expense

$158

$439

$574

$549

'

'

'

'

'

'

'

'

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	0 Months Ended		6 Months Ended
	Oct. 29, 2014	Jul. 28, 2014	Oct. 31, 2014
Series D Preferred Stock [Member]	'	'	'
Class of Stock [Line Items]	'	'	'
Declaration date	29-Oct-14	28-Jul-14	'
Dividend per share (in dollars per share)	$0.66	$0.66	'
Cumulative dividend rate per annum (percent)	'	'	10.50%
Par value (in dollars per share)	'	'	$25
Record Date	14-Nov-14	15-Aug-14	'
Payment date	1-Dec-14	2-Sep-14	'
Series C Preferred Stock [Member]	'	'	'
Class of Stock [Line Items]	'	'	'
Declaration date	29-Oct-14	28-Jul-14	'
Dividend per share (in dollars per share)	$0.67	$0.67	'
Cumulative dividend rate per annum (percent)	'	'	10.75%
Par value (in dollars per share)	'	'	$25
Record Date	14-Nov-14	15-Aug-14	'
Payment date	1-Dec-14	2-Sep-14	'

Stockholders_Equity_DetailsTex

Stockholders' Equity (DetailsTextual)	6 Months Ended
	Oct. 31, 2014	Apr. 30, 2014
Stockholders' Equity Note [Abstract]	'	'
Shares outstanding (in shares)	46,599,471	45,756,697
Shares issued (in shares)	842,774	'
Shares issued for compensation (in shares)	521,420	'
Exercise of equity rights (in shares)	321,354	'

Stockholders_Equity_Details_Te

Stockholders' Equity (Details Textual 1) (USD $)	6 Months Ended				0 Months Ended	3 Months Ended	6 Months Ended
In Thousands, except Share data, unless otherwise specified	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Apr. 30, 2014	Aug. 25, 2014	Oct. 31, 2014	Oct. 31, 2014	Aug. 25, 2014	Apr. 30, 2014
			Series C Preferred Stock [Member]	Series C Preferred Stock [Member]	Series D Preferred Stock [Member]	Series D Preferred Stock [Member]	Series D Preferred Stock [Member]	Series D Preferred Stock [Member]	Series D Preferred Stock [Member]
Class of Stock [Line Items]	'	'	'	'	'	'	'	'	'
Preferred Stock, Fair Value	'	'	$71,684	$77,976	'	$47,171	$47,171	'	$31,330
Shares issued during period (in shares)	'	'	'	'	'	16,120	'	'	'
Cumulative dividend rate per annum (percent)	'	'	10.75%	'	'	'	10.50%	'	'
Net proceeds	'	'	'	'	17,023	'	400	'	'
Liquidation preference (in dollars per share)	'	'	'	'	'	$25	$25	'	'
Shares issued (in shares)	'	'	'	'	'	2,112,458	2,112,458	750,000	1,070,448
Price per share (in dollars per share)	'	'	'	'	'	'	'	$24.50	'
Gross proceeds	'	'	'	'	18,375	'	'	'	'
Issuance costs	$1,412	$3,683	'	'	$1,352	'	'	'	'

Income_Taxes_Details

Income Taxes (Details) (USD $)	6 Months Ended
	Oct. 31, 2014
Income Tax Disclosure [Abstract]	'
Effective tax rate (benefit) (percent)	41.00%
Federal statutory rate (percent)	35.00%
Income taxes paid	'
Significant payments expected	'

Alaska_Production_Credits_Deta

Alaska Production Credits (Details) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014		Oct. 31, 2013
State Production Credit Receivable, Annual Loss Credits [Roll Forward]	'		'
Balance, April 30, 2014	$49,121		'
Applications for carried-forward annual loss credits	2,732	[1]	'
Expenditure and Exploration Credits, Amount	41,843	[1]	'
Applications for expenditure and exploration based credits	41,843		5,642
Cash collections for expenditure and exploration based credits	-56,012		'
Balance, October 31, 2014	$37,684		'
[1]	Applications for carried-forward annual loss credits and for expenditure and exploration based credits are recorded net of established reserves and also include revisions to prior period applications, if applicable.

Alaska_Production_Credits_Deta1

Alaska Production Credits (Details Textual) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2014		Apr. 30, 2014
Alaska Production Tax Credits [Line Items]	'		'
Net carried-forward annual loss credits	$2,732	[1]	'
Expenditure and exploration credits	84,770		'
Alaska production credits receivable, net	$37,684		$49,121
43.55.023(a)(1) [Member]	'		'
Alaska Production Tax Credits [Line Items]	'		'
Alaska capital expenditure credit (percent)	20.00%		'
43.55.023(1)(1) [Member]	'		'
Alaska Production Tax Credits [Line Items]	'		'
Alaska capital expenditure credit (percent)	40.00%		'
43.55.023(a)(2) [Member]	'		'
Alaska Production Tax Credits [Line Items]	'		'
Alaska capital exploration credit (percent)	20.00%		'
43.55.023(1)(2) [Member]	'		'
Alaska Production Tax Credits [Line Items]	'		'
Alaska capital exploration credit (percent)	40.00%		'
43.55.023(b) [Member]	'		'
Alaska Production Tax Credits [Line Items]	'		'
Alaska carried-forward annual loss credit (percent)	25.00%		'
43.55.025 [Member]	'		'
Alaska Production Tax Credits [Line Items]	'		'
Seismic exploration credits (percent)	40.00%		'
[1]	Applications for carried-forward annual loss credits and for expenditure and exploration based credits are recorded net of established reserves and also include revisions to prior period applications, if applicable.

Litigation_Details

Litigation (Details) (USD $)	0 Months Ended		6 Months Ended			0 Months Ended
	Jun. 03, 2014	17-May-11	Oct. 31, 2014	29-May-13	17-May-11	Feb. 07, 2014	Feb. 03, 2015
						Indemnification Agreement [Member]	Scenario, Forecast [Member]
Loss Contingencies [Line Items]	'	'	'	'	'	'	'
Damages sought, minimum	'	'	'	'	$3,000,000	'	'
Damages sought for loss of vested warrants	'	2,687,000	'	'	'	'	'
Reimbursement due from plaintiff	9,000	'	'	'	'	'	'
Litigation settlement	'	'	'	'	'	500,000	2,950,000
Estimated possible loss	'	'	'	1,889,000	'	'	'
Gain related to settlement	'	'	$113,000	'	'	'	'

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	6 Months Ended	0 Months Ended	6 Months Ended	0 Months Ended
	Oct. 31, 2014	Dec. 01, 2014	Oct. 31, 2014	Dec. 01, 2014
	Series C Preferred Stock [Member]	Series C Preferred Stock [Member]	Series D Preferred Stock [Member]	Series D Preferred Stock [Member]
		Subsequent Event [Member]		Subsequent Event [Member]
Subsequent Event [Line Items]	'	'	'	'
Dividend paid (in dollars per share)	'	$0.67	'	$0.66
Cumulative dividend rate per annum (percent)	10.75%	'	10.50%	'
Par value (in dollars per share)	$25	'	$25	'

Subsequent_Events_Details_Text

Subsequent Events (Details Textual) (USD $)	0 Months Ended		0 Months Ended
In Thousands, unless otherwise specified	Nov. 20, 2014	Nov. 20, 2014	Dec. 31, 2014	Dec. 31, 2014
	Tennessee Divestiture [Member]	Tennessee Divestiture [Member]	Scenario, Forecast [Member]	Scenario, Forecast [Member]
	Subsequent Event [Member]	Subsequent Event [Member]	Savant Alaska, LLC [Member]	Savant Alaska, LLC [Member]
Subsequent Event [Line Items]	'	'	'	'
Gain from Tennessee divestiture	$3,250	'	'	'
Liquidated inventory	'	600	'	'
Acquisition cost	'	'	$9,000	'
Working interest acquired (percent)	'	'	'	67.50%
Ownership in nearby leases (percent)	'	'	'	100.00%
ASRC Exploration, LLC working interest ownership (percent)	'	'	'	32.50%

Subsequent_Events_Details_Text1

Subsequent Events (Details Textual 1) (USD $)	Oct. 31, 2014	Dec. 10, 2014	Oct. 31, 2014	Feb. 03, 2014	Dec. 10, 2014	Dec. 10, 2014	Dec. 10, 2014	Dec. 10, 2014
	First Lien RBL [Member]	First Lien RBL [Member]	Second Lien Credit Facility [Member]	Second Lien Credit Facility [Member]	Second Lien Credit Facility [Member]	Second Lien Credit Facility [Member]	Minimum [Member]	Maximum [Member]
		Subsequent Event [Member]			Subsequent Event [Member]	Subsequent Event [Member]	Second Lien Credit Facility [Member]	Second Lien Credit Facility [Member]
							Subsequent Event [Member]	Subsequent Event [Member]
Subsequent Event [Line Items]	'	'	'	'	'	'	'	'
Additional issuable preferred stock	'	$25,000,000	'	'	'	$25,000,000	'	'
Liquidation preference	'	50,000,000	'	'	'	50,000,000	'	'
Required percent of properties subject to mortgage (percent)	80.00%	90.00%	80.00%	'	'	90.00%	'	'
Maximum borrowing base	'	50,000,000	'	175,000,000	'	'	'	'
Potential maximum borrowing base	'	40,000,000	'	'	'	'	'	'
Increase to interest rate per annum (percent)	'	'	'	'	'	'	1.00%	2.00%
Net proceeds needed to decrease interest rate	'	'	'	'	$20,000,000	'	'	'