Miller Energy Resources (MILL) 10-Q 12 Mar 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Jan. 31, 2014	Mar. 05, 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	31-Jan-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	45,242,197

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Jan. 31, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
CURRENT ASSETS:	'	'
Cash and cash equivalents	$13,184	$2,551
Restricted cash	4,066	7,531
Accounts receivable	1,137	3,204
Alaska production tax credits receivable	19,763	12,713
Inventory	4,944	3,382
Prepaid expenses and other	8,371	1,183
Total current assets	51,465	30,564
OIL AND GAS PROPERTIES, NET	568,808	491,314
EQUIPMENT, NET	34,860	37,571
OTHER ASSETS:	'	'
Land	542	542
Restricted cash, non-current	12,007	10,207
Deferred financing costs, net	1,607	2,085
Other assets	1,809	541
Total assets	671,098	572,824
CURRENT LIABILITIES:	'	'
Accounts payable	40,538	13,129
Accrued expenses	18,527	6,338
Short-term portion of derivative instruments	1,758	842
Current portion of long-term debt	0	6,000
Total current liabilities	60,823	26,309
OTHER LIABILITIES:	'	'
Deferred income taxes	145,890	157,530
Asset retirement obligation	20,967	19,890
Long-term portion of derivative instruments	3,152	'
Long-term debt, less current portion	74,268	48,978
Total liabilities	305,100	252,707
COMMITMENTS AND CONTINGENCIES (Note 14)	'	'
MEZZANINE EQUITY:	'	'
Series C Cumulative Preferred Stock, redemption amount of $78,124, 3,250,000 shares authorized, 3,069,968 and 1,454,901 shares issued and outstanding as of January 31, 2014 and April 30, 2013, respectively	67,097	31,236
STOCKHOLDERS' EQUITY:	'	'
Series D Cumulative Redeemable Preferred Stock, redemption amount of $32,342, 4,000,000 shares authorized, 1,069,031 and 0 shares issued and outstanding as of January 31, 2014 and April 30, 2013, respectively	29,885	'
Series D Cumulative Redeemable Preferred Stock, held in escrow (Note 10)	5,000	'
Common stock, $0.0001 par, 500,000,000 shares authorized, 45,231,447 and 43,444,694 shares issued and outstanding as of January 31, 2014 and April 30, 2013, respectively	4	4
Additional paid-in capital	97,845	88,184
Retained earnings	176,167	200,693
Total stockholders' equity	298,901	288,881
Total liabilities and stockholders' equity	$671,098	$572,824

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Jan. 31, 2014	Apr. 30, 2013	Jan. 31, 2014	Apr. 30, 2013	Jan. 31, 2014
			Series C Preferred Stock [Member]	Series C Preferred Stock [Member]	Series D Preferred Stock [Member]
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)	45,231,447	43,444,694	'	'	'
Shares outstanding (in shares)	45,231,447	43,444,694	'	'	'
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	1,454,901	'
Shares outstanding (in shares)	'	'	3,069,968	1,454,901	'
Series D redemption amount	'	'	'	'	$32,342,000
Shares authorized (in shares)	'	'	'	'	4,000,000
Shares issued (in shares)	'	'	'	'	1,069,301
Shares outstanding (in shares)	'	'	'	'	1,069,301

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2014	Jan. 31, 2013
REVENUES:	'	'	'	'
Oil sales	$16,348	$6,720	$47,012	$22,310
Natural gas sales	118	133	671	328
Other	162	1,146	749	4,433
Total revenues	16,628	7,999	48,432	27,071
OPERATING EXPENSES:	'	'	'	'
Oil and gas operating	5,821	4,118	18,249	12,963
Cost of other revenue	256	1,051	844	4,084
General and administrative	7,587	5,518	21,092	17,056
Exploration expense	352	187	786	244
Depreciation, depletion and amortization	7,642	3,341	22,352	9,528
Accretion of asset retirement obligation	305	284	903	853
Other operating expense (income), net	1,250	'	1,250	-65
Total operating expenses	23,213	14,499	65,476	44,663
OPERATING LOSS	-6,585	-6,500	-17,044	-17,592
OTHER INCOME (EXPENSE):	'	'	'	'
Interest expense, net	-407	-1,117	-4,051	-2,785
Gain (loss) on derivatives, net	1,677	-1,681	-5,589	5,215
Other income (expense), net	42	25	26	-350
Total other income (expense)	1,312	-2,773	-9,614	2,080
LOSS BEFORE INCOME TAXES	-5,273	-9,273	-26,658	-15,512
Income tax benefit	2,171	3,931	11,640	6,551
NET LOSS	-3,102	-5,342	-15,018	-8,961
Accretion of Series A, C and D preferred stock	-817	-145	-1,935	-2,605
Series C and D preferred stock cumulative dividends	-2,905	-677	-7,573	-809
NET LOSS ATTRIBUTABLE TO COMMON STOCKHOLDERS	($6,824)	($6,164)	($24,526)	($12,375)
LOSS PER COMMON SHARE:	'	'	'	'
Basic (in dollars per share)	($0.15)	($0.14)	($0.56)	($0.29)
Diluted (in dollars per share)	($0.15)	($0.14)	($0.56)	($0.29)
WEIGHTED AVERAGE NUMBER OF COMMON SHARES:	'	'	'	'
Basic (in shares)	44,886,838	43,367,781	44,141,222	42,445,223
Diluted (in shares)	44,886,838	43,367,781	44,141,222	42,445,223

Condensed_Consolidated_Stateme1

Condensed Consolidated Statement of Stockholders' Equity (USD $)	Total	Mezzanine Equity [Member]	Series C Preferred Stock [Member]	Series D Preferred Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Deficit) [Member]	Retained Earnings (Deficit) [Member]	Retained Earnings (Deficit) [Member]	Retained Earnings (Deficit) [Member]
In Thousands, except Share data, unless otherwise specified					Series D Preferred Stock [Member]				Mezzanine Equity [Member]	Series C Preferred Stock [Member]	Series D Preferred Stock [Member]
Balance at Apr. 30, 2012	$291,005	'	'	'	'	$4	$64,813	$226,188	'	'	'
Balance (in shares) at Apr. 30, 2012	'	'	'	'	'	41,086,751	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'	'	'	'
Net loss	-8,961	'	'	'	'	'	'	-8,961	'	'	'
Series C preferred dividends	'	'	-809	'	'	'	'	'	'	-809	'
Accretion of preferred stock	-2,605	-2,605	'	'	'	'	'	'	-2,605	'	'
Issuance of equity for services	2,047	'	'	'	'	'	2,047	'	'	'	'
Issuance of equity for services (in shares)	'	'	'	'	'	351,477	'	'	'	'	'
Other equity issuances	1,341	'	'	'	'	'	1,341	'	'	'	'
Other equity issuances (in shares)	'	'	'	'	'	192,800	'	'	'	'	'
Issuance of equity for compensation	8,710	'	'	'	'	'	8,710	'	'	'	'
Issuance of equity for compensation (in shares)	'	'	'	'	'	454,665	'	'	'	'	'
Exercise of equity rights	3,832	'	'	'	'	'	3,832	'	'	'	'
Exercise of equity rights (in shares)	1,286,001	'	'	'	'	1,286,001	'	'	'	'	'
Preferred stock redemption	2,510	'	'	'	'	'	2,510	'	'	'	'
Modification of warrants	1,840	'	'	'	'	'	1,840	'	'	'	'
Balance at Jan. 31, 2013	298,910	'	'	'	'	4	85,093	213,813	'	'	'
Balance (in shares) at Jan. 31, 2013	'	'	'	'	'	43,371,694	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'	'	'	'
Net loss	-11,459	'	'	'	'	'	'	-11,459	'	'	'
Series C preferred dividends	'	'	-1,400	'	'	'	'	'	'	-1,400	'
Accretion of preferred stock	'	'	-261	'	'	'	'	'	'	-261	'
Issuance of equity for services	107	'	'	'	'	'	107	'	'	'	'
Issuance of equity for compensation	2,984	'	'	'	'	'	2,984	'	'	'	'
Issuance of equity for compensation (in shares)	'	'	'	'	'	73,000	'	'	'	'	'
Balance at Apr. 30, 2013	288,881	'	'	'	'	4	88,184	200,693	'	'	'
Balance (in shares) at Apr. 30, 2013	'	'	'	'	'	43,444,694	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'	'	'	'	'
Net loss	-15,018	'	'	'	'	'	'	-15,018	'	'	'
Series C preferred dividends	'	'	-6,286	'	'	'	'	'	'	-6,286	'
Accretion of preferred stock	-1,935	'	-1,796	'	'	'	'	'	'	-1,796	'
Issuance of equity for services	752	'	'	'	'	'	752	'	'	'	'
Other equity issuances	3	'	'	'	'	'	3	'	'	'	'
Issuance of equity for compensation	4,368	'	'	'	'	'	4,368	'	'	'	'
Issuance of equity for compensation (in shares)	'	'	'	'	'	205,099	'	'	'	'	'
Exercise of equity rights	4,538	'	'	'	'	'	4,538	'	'	'	'
Exercise of equity rights (in shares)	1,581,654	'	'	'	'	1,581,654	'	'	'	'	'
Issuance of Series D Preferred Stock	'	'	'	29,746	29,746	'	'	'	'	'	'
Issuance of Series D Preferred Stock (in shares)	'	'	'	'	1,282,617	'	'	'	'	'	'
Series D Preferred Stock held in escrow	'	'	'	-5,000	-5,000	'	'	'	'	'	'
Series D Preferred Stock held in escrow (in shares)	'	'	'	'	-213,586	'	'	'	'	'	'
Series D preferred dividends	'	'	'	-1,287	'	'	'	'	'	'	-1,287
Accretion of Series D Preferred Stock	0	'	'	139	139	'	'	-139	'	'	'
Balance at Jan. 31, 2014	$298,901	'	'	'	$24,885	$4	$97,845	$176,167	'	'	'
Balance (in shares) at Jan. 31, 2014	'	'	'	'	1,069,031	45,231,447	'	'	'	'	'

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
Net loss	($15,018)	($8,961)
Adjustments to reconcile net loss to net cash provided by operating activities:	'	'
Depreciation, depletion and amortization	22,352	9,528
Amortization of deferred financing fees and debt discount	1,113	549
Expense from issuance of equity	5,120	7,630
Dry hole costs, leasehold impairments and non-cash exploration expenses	157	'
Deferred income taxes	-11,640	-6,551
Derivative contracts:	'	'
(Gain) loss on derivatives, net	5,589	-5,215
Cash settlements	-2,765	2,276
Accretion of asset retirement obligation	903	853
Other	1,949	'
Changes in operating assets and liabilities:	'	'
Receivables	5,084	996
Inventory	372	-467
Prepaid expenses and other assets	-1,788	-1,445
Accounts payable, accrued expenses and other	3,849	6,944
NET CASH PROVIDED BY OPERATING ACTIVITIES	15,277	6,137
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Capital expenditures for oil and gas properties	-94,388	-23,213
Proceeds from Alaska production tax credits for capital expenditures	18,561	'
North Fork purchase deposit	-3,000	'
Prepayment of drilling costs	-2,302	'
Purchase of equipment and improvements	-986	-9,606
Proceeds from sale of equipment	'	2,000
NET CASH USED IN INVESTING ACTIVITIES	-82,115	-30,819
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'
Cash dividends	-5,646	-285
Payments on debt	'	-24,130
Proceeds from borrowings	20,000	40,000
Debt acquisition costs	-1,900	-3,854
Redemption of preferred stock	'	-11,240
Issuance of preferred stock	62,704	20,448
Equity issuance costs	-3,893	-1,576
Exercise of equity rights	4,538	3,832
Restricted cash	1,665	-992
Other	3	'
NET CASH PROVIDED BY FINANCING ACTIVITIES	77,471	22,203
NET CHANGE IN CASH AND CASH EQUIVALENTS	10,633	-2,479
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	2,551	3,971
CASH AND CASH EQUIVALENTS AT END OF PERIOD	13,184	1,492
SUPPLEMENTARY CASH FLOW DATA:	'	'
Cash paid for interest	5,805	8,895
SIGNIFICANT NON-CASH INVESTING AND FINANCING ACTIVITIES:	'	'
Capital expenditures in accounts payable and accrued expenses	32,572	6,702
Reduction of oil and gas properties and equipment from applications for Alaska production tax credits	28,906	'
Issuance of Series D Preferred Stock held in escrow	5,000	'
Accretion of preferred stock	$1,935	$2,605

Organization_and_Basis_of_Pres

Organization and Basis of Presentation	9 Months Ended
	Jan. 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, Inc.," 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 Drilling, TN LLC, Miller Energy Services, LLC, East Tennessee Consultants, Inc., East Tennessee Consultants II, LLC, Miller Energy GP, LLC, and Cook Inlet Energy, LLC ("CIE"), 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 the Cook Inlet Basin of southcentral Alaska and the Appalachian region of east Tennessee. The accounting policies used by us and our subsidiaries reflect industry practices and conform to U.S. generally accepted accounting principles ("GAAP"). Significant policies are discussed below.
	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, 2013, which was filed with the SEC on July 15, 2013 and was amended on August 28, 2013. Certain amounts in the condensed consolidated financial statements and notes thereto have been reclassified to conform to current period presentation.
	Immaterial Reclassifications to Prior Period Consolidated Balance Sheets
	We reclassified a $5,305 contra asset related to Alaska production tax credits from oil and gas properties to equipment. The credits that resulted in the recognition of the contra asset related to our drilling rigs, the costs of which are classified in equipment. We have determined the reclassification to be immaterial to the prior period consolidated balance sheet taken as a whole. This error did not have an impact on the prior period consolidated statements of operations, equity or cash flows.
		As Presented					As Adjusted
		30-Apr-13		Reclassifications			30-Apr-13
	Oil and gas properties, net	$	486,009	$	5,305		$	491,314
	Equipment, net	$	42,876	$	(5,305	)	$	37,571
	In addition, we reclassified certain costs related to the issuance of debt under our Prior Credit Facility that were paid to our lender. The costs were initially recorded and reflected as deferred financing costs on our condensed consolidated balance sheet and have been reclassified as a debt discount. We have determined the reclassification to be immaterial to the prior period consolidated balance sheet taken as a whole. This error did not have an impact on the prior period consolidated statements of operations, equity or cash flows.
		As Presented					As Adjusted
		30-Apr-13		Reclassifications			30-Apr-13
	Deferred financing costs, net	$	4,666	$	(2,581	)	$	2,085
	Long-term debt, less current portion	$	51,559	$	(2,581	)	$	48,978

Summary_of_Significant_Account

Summary of Significant Accounting Policies	9 Months Ended
	Jan. 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, 2013, as amended.
	Principles of Consolidation
	The accompanying condensed consolidated financial statements include our consolidated accounts, including the accounts of the Company, 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.
	Restricted Cash
	As of January 31, 2014 and April 30, 2013, current restricted cash includes $3,447 and $7,144, respectively, of cash temporarily held in an account that is controlled by our lender. Current restricted cash balances also include amounts held in escrow to secure Company related credit cards and certain amounts held for and to be paid out to working interest owners. Non-current restricted cash balances include amounts held in escrow to provide for the future plugging and abandonment of wells, the possible dismantling of our off-shore platform, performance bonds and general liability bonds.
	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. No impairment of proved properties was recognized during the nine months ended January 31, 2014 or January 31, 2013.
	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. During the nine months ended January 31, 2014 our condensed consolidated statement of operations includes $157 related to impairment of certain unproved properties and $625 in seismic and delay rentals incurred in the Cook Inlet region. We had $4 in exploration and abandonment expenses in the Appalachian region during the nine months ended January 31, 2014.
	Equipment
	Equipment includes drilling rigs, automobiles, trucks, an airplane, office furniture, computer equipment, and buildings. These items are recorded at cost and are depreciated on the straight-line method based on expected lives of the individual assets or group of assets, which range from five to forty years.
	Equipment is reviewed for impairment when facts and circumstances indicate that book values may not be recoverable. In performing this review, an undiscounted cash flow test is performed at the lowest level for which identifiable cash flows are independent of cash flows from other assets. If the sum of the undiscounted estimated future net cash flows is less than the net book value of the property, an impairment loss is recognized for the excess, if any, of the property's net book value over its estimated fair value.
	Investments
	On June 24, 2011, we acquired a 48% minority interest in Pellissippi Pointe I, LLC and Pellissippi Pointe II, LLC (the "Pellissippi Pointe" entities or "investee") for total cash consideration of $400. In connection with the transaction, we executed a five-year lease agreement with the investee and relocated our corporate offices to the new facility on November 7, 2011. Since we do not exercise control over the financial and operating decisions made by the investee, we have accounted for these investments using the equity method. These investments are reflected in other assets in the accompanying condensed consolidated balance sheets.
	Guarantees
	On July 12, 2012, we signed a direct guarantee for 55% of the $5,074 outstanding loan obligations with FSG Bank for the Pellissippi Pointe equity investment. The Company's guarantee is included within the scope of Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") 460, "Guarantees" and was recorded at the estimated fair value of $250; such amount is included in accrued expenses on our condensed consolidated balance sheet as of January 31, 2014 and is being amortized over the five-year life of the guarantee. The fair value was calculated using the income approach and the estimated default rate was determined by obtaining the average cumulative issuer-weighted corporate default rate based on the credit rating of Pellissippi Pointe and the term of the underlying loan obligations. The default rates are published by Moody's Investors Service. To the extent we are required to make payments under the guarantee, we will record the differences between the liability and the associated payments in earnings. At January 31, 2014, our maximum potential undiscounted payment under this arrangement is $2,791 plus additional lender's costs.
	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 January 31, 2014 our cumulative dividends were $7,573.
	New Accounting Pronouncements
	In December 2011, the FASB issued Accounting Standards Update ("ASU") 2011-11, "Disclosures about Offsetting Assets and Liabilities," which increases disclosures about offsetting assets and liabilities. The new disclosures are required to enable users of financial statements to understand significant quantitative differences in balance sheets prepared under GAAP and International Financial Reporting Standards ("IFRS") related to the offsetting of financial instruments. The existing GAAP guidance allowing balance sheet offsetting, including industry-specific guidance, remains unchanged. The guidance in ASU 2011-11 was effective for annual and interim reporting periods beginning on or after January 1, 2013. The disclosures should be applied retrospectively for all prior periods presented. We have adopted ASU 2011-11; however, it did not have a material impact to 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.

Major_Customers_and_Concentrat

Major Customers and Concentrations of Credit Risk	9 Months Ended
	Jan. 31, 2014
Risks and Uncertainties [Abstract]	'
Major Customers and Concentrations of Credit Risk	'
	MAJOR CUSTOMERS AND CONCENTRATIONS OF CREDIT RISK
	For the three and nine months ended January 31, 2014, Tesoro Corporation accounted for 95% and 93% of our consolidated total revenues, respectively. Tesoro Corporation also accounted for 14% and 55%, of our accounts receivable as of January 31, 2014 and April 30, 2013, respectively.
	Credit is extended to customers based on an evaluation of their credit worthiness and collateral is generally not required. We experienced no credit losses of significance during the nine months ended January 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 January 31, 2014, we held $15,677 in excess of the $250 limit insured by the Federal Deposit Insurance Corporation.

Related_Party_Transactions

Related Party Transactions	9 Months Ended
	Jan. 31, 2014
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	RELATED PARTY TRANSACTIONS
	We use a number of contract labor companies to provide on demand 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 a member of our Board of Directors and Chief Operating Officer ("COO") of Miller, as well as the Chief Executive Officer ("CEO") of CIE. For the three and nine months ended January 31, 2014, we paid H&H Industrial a total of $450 and $1,349, respectively. We have used Rediske Air, Inc. ("Rediske Air") to provide transportation to our facilities. Rediske Air was owned by David Hall's brother-in-law, who passed away on July 7, 2013. Rediske Air is no longer owned by a related party. For the three and nine months ended January 31, 2014, we paid Rediske Air a total of $281 and $865, 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.
	The Company is required to remit payroll taxes related to certain stock-based compensation transactions. As of January 31, 2014, we had a payable of $36 and no receivable. At April 30, 2013, we had a payable of $620 and a corresponding receivable from the respective employees of $593, which was collected subsequent to April 30, 2013.
	In 2009, we formed both Miller Energy GP and Miller Energy Income 2009-A, LP ("MEI") to raise capital necessary to support strategic business initiatives. From November 2009 to May 2010 we entered into three secured promissory notes with MEI to borrow $3,071 with maturity dates ranging from November 2013 to May 2014. On June 29, 2012, the maturity dates on the promissory notes were amended to reflect the later of (i) 91 days after the date on which the Apollo Credit Facility is extinguished, or (ii) July 31, 2017. Our wholly owned subsidiary, Miller Energy GP, owns 1% of MEI; however, due to the shared management of our company and MEI, we consolidate this entity. We have not presented non-controlling interest on our condensed consolidated balance sheets or our condensed consolidated statements of operations since these amounts are immaterial.
	On September 18, 2013, the Company entered into a one-year consulting agreement with William R. Weakley under which he agreed to assist us with investor relations and outreach, including advising the company on its communications with high net-worth individuals, helping to further the Company’s related business goals, assisting with our strategic planning, providing management and business advice, and other consulting services we may reasonably request.  Mr. Weakley is a related party to the Company as a result of aggregating his personal holdings in our stock with those of his brother, son-in-law and other of his relatives which, taken together, exceed 5% of the outstanding common stock of the Company.  As compensation for these services, we granted Mr. Weakley a warrant to purchase 300,000 shares of our common stock at an exercise price of $6.63 per share.  So long as the warrant has not otherwise terminated prior to that date, this warrant will vest in full and be exercisable on September 18, 2014.  The warrant will terminate if the related consulting agreement is terminated prior to the end of its one-year term.  The warrant will otherwise terminate on the earlier of the one year anniversary of the death or disability of Mr. Weakley or September 18, 2016. 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.  We further note that in an unrelated transaction, Mr. Weakley's son-in-law extended a personal loan to our CEO, Scott M. Boruff.  The Company is not a party to or otherwise involved in this loan, though this transaction was disclosed to the Audit Committee of our Board of Directors in connection with its evaluation of the consulting agreement with Mr. Weakley. For the three and nine months ended January 31, 2014, we paid Mr. Weakley a total of $2 and $2, respectively.

Oil_and_Gas_Properties_and_Equ

Oil and Gas Properties and Equipment	9 Months Ended
	Jan. 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:
		January 31,			April 30,
		2014			2013
	Property costs
	Proved property	$	389,810		$	332,241
	Unproved property	235,134			196,500
	Total property costs	624,944			528,741
	Less: Accumulated depletion	(56,136		)	(37,427		)
	Oil and gas properties, net	$	568,808		$	491,314
	Equipment is summarized as follows:
		January 31,			April 30,
		2014			2013
	Machinery and equipment	$	7,748		$	7,413
	Vehicles	1,877			1,851
	Aircraft	476			476
	Buildings	2,725			2,725
	Office equipment	812			759
	Leasehold improvements	485			482
	Drilling rigs	30,117			30,117
		44,240			43,823
	Less: Accumulated depreciation	(9,380		)	(6,252		)
	Equipment, net	$	34,860		$	37,571
	Depreciation, depletion and amortization consisted of the following:
		For the Nine Months Ended January 31,
		2014			2013
	Depletion of oil and gas related assets	$	19,158		$	7,240
	Depreciation and amortization of equipment	3,194			2,288
	Total	$	22,352		$	9,528

Derivative_Instruments_and_Fai

Derivative Instruments and Fair Value Measurements	9 Months Ended
	Jan. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments and Fair Value Measurements	'
	DERIVATIVE INSTRUMENTS AND FAIR VALUE MEASUREMENTS
	Derivative Instruments
	Commodity Derivatives
	We are exposed to fluctuations in crude oil prices on the majority of our production. As a result, our management believes it is prudent to manage the variability in cash flows by occasionally entering into hedges on a portion of our crude oil production. We primarily utilize over-the-counter variable-to-fixed price commodity swap contracts to manage fluctuations in cash flows resulting from changes in commodity prices. The Company's derivative instruments were not designated as hedges for accounting purposes for any of the periods presented. In accordance with ASC 815 "Derivatives and Hedging," the changes in fair value are recognized in the condensed consolidated statement of operations in the period of change. Gains and losses on derivatives are included in cash flows from operating activities.
	As of January 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
	2014		191,400			$	102.92
	2015		785,000			100.58
	2016		787,600			95.75
	2017		232,600			94.27
	Derivative Activities Reflected on Condensed Consolidated Balance Sheets
	The Company reports the fair value of derivatives on the condensed consolidated balance sheets in derivative instrument assets and derivative instrument liabilities as either current or noncurrent. The Company determines the current and noncurrent classification based on the timing of the expected future cash flows of individual trades. The Company reports these amounts on a net basis by counterparty where right of offset or master netting agreements exists. As of January 31, 2014 and April 30, 2013, the fair market value of our derivative liabilities was as follows:
			Asset Derivatives											Liability Derivatives
			January 31, 2014						April 30, 2013					January 31, 2014				April 30, 2013
	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		$	564			Prepaid expenses and other		$	—		Current portion of derivative instruments	$	(1,758	)	Current portion of derivative instruments	$	(842	)
	Commodity derivatives		Other assets		680				Other assets		—			Long-term portion of derivative instruments	(3,152		)	Long-term portion of derivative instruments	—
	Total derivatives not designated as hedging instruments under ASC 815				$	1,244					$	—			$	(4,910	)		$	(842	)
	Offsetting of Derivative Assets and Liabilities
	The following table presents our gross and net derivative assets and liabilities:
		Gross Amount				Netting Adjustments (a)				Net Amount Presented on Balance Sheet
	January 31, 2014
	Derivative assets with right of offset or master netting agreements	$	1,244			$	—			$	1,244
	Derivative liabilities with right of offset or master netting agreements	$	(4,910	)		$	—			$	(4,910	)
	April 30, 2013
	Derivative assets with right of offset or master netting agreements	$	—			$	—			$	—
	Derivative liabilities with right of offset or master netting agreements	$	(842	)		$	—			$	(842	)
	—————————
	(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 January 31,								For the Nine Months Ended January 31,
		2014				2013				2014			2013
	Gain (loss) on derivatives, net	$	1,677			$	(1,681	)		$	(5,589	)	$	5,215
	Fair Value Measurements
	Fair Value Hierarchy
	ASC 820, "Fair Value Measurements and Disclosures," provides a hierarchy that prioritizes and defines the types of inputs used to measure fair value. The fair value hierarchy gives the highest priority to Level 1 inputs, which consist of unadjusted quoted prices for identical instruments in active markets. Level 2 inputs consist of quoted prices for similar instruments. Level 3 valuations are derived from inputs that are significant and unobservable; hence, these valuations have the lowest priority.
	The valuation techniques that may be used to measure fair value include a market approach, an income approach and a cost approach. A market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities. An income approach uses valuation techniques to convert future amounts to a single present amount based on current market expectations, including present value techniques, option-pricing models and excess earnings method. A cost approach is based on the amount that currently would be required to replace the service capacity of an asset (replacement cost).
	Fair Value Measurement on a Recurring Basis
	The following table presents, by level within the fair value hierarchy, the Company's assets and liabilities that are measured at fair value on a recurring basis as of January 31, 2014 and April 30, 2013. The carrying amounts reported in the condensed consolidated balance sheets for cash and cash equivalents, restricted cash, accounts receivable and accounts payable approximate fair value due to the nature of the instrument and/or the short-term maturity of these instruments.
		Fair Value Measurements
	At January 31, 2014	Level 1				Level 2				Level 3
	Commodity derivative asset	$	—			$	1,244			$	—
	Commodity derivative liability	$	—			$	(4,910	)		$	—
	Total	$	—			$	(3,666	)		$	—
	At April 30, 2013
	Commodity derivative asset	$	—			$	—			$	—
	Commodity derivative liability	$	—			$	(842	)		$	—
	Total	$	—			$	(842	)		$	—
	Our commodity derivatives consist of over-the-counter variable-to-fixed price commodity swaps. The fair values of our commodity derivatives are not actively quoted in the open market, thus we use an income approach to estimate fair value. Significant level 2 assumptions used to measure the fair value of the commodity derivatives include current market and contractual crude oil prices, appropriate risk adjusted discount rates, and other relevant data.
	Reclassifications of fair value between Level 1, Level 2 and Level 3 of the fair value hierarchy, if applicable, are made at the end of each quarter. There were no transfers between Level 1, Level 2 or Level 3 during the nine months ended January 31, 2014 or 2013.

Debt

Debt	9 Months Ended
	Jan. 31, 2014
Debt Disclosure [Abstract]	'
Debt	'
	DEBT
	As of January 31, 2014 and April 30, 2013, we had the following debt obligations reflected at their respective carrying values on our condensed consolidated balance sheets:
		January 31,			April 30,
		2014			2013
	Apollo senior secured Credit Facility	$	75,307		$	55,307
	Debt discount related to Apollo senior secured Credit Facility	(3,346		)	(2,581		)
	Series B Preferred Stock	2,307			2,252
	Total debt obligations	$	74,268		$	54,978
	Apollo Senior Secured Credit Facility
	On June 29, 2012 (the "Closing Date"), we entered into a Loan Agreement (the "Prior Loan Agreement") with Apollo Investment Corporation ("Apollo"), as administrative agent and sole initial lender. The Prior Loan Agreement provided for a $100,000 credit facility (the "Prior Credit Facility") with an initial borrowing base of $55,000 (the "Original Availability"). Of that initial $55,000, $40,000 was made available to and was drawn by us on the Closing Date. On February 7, 2013 and April 25, 2013, we borrowed an additional $5,000 and $10,000, respectively, under the Prior Credit Facility, exhausting the Original Availability. On August 5, 2013, the amount available to us under the Prior Credit Facility was increased by an additional $20,000, to a total of $75,000, when a second tranche of loans (the "Additional Availability") was added to the Prior Loan Agreement after negotiations with Apollo. This additional $20,000 in availability was immediately drawn by us.
	As noted below, on February 3, 2014, we refinanced the Prior Credit Facility by entering into an Amended and Restated Credit Agreement (the "New Loan Agreement") among us, as a borrower, Apollo, as administrative agent (in that capacity the "Administrative Agent"), and the lenders from time to time party thereto (the "Lenders"), which amended and replaced the terms of the Prior Credit Facility.
	The Prior Credit Facility was scheduled to mature on June 29, 2017 and was secured by substantially all of our assets and those of our consolidated subsidiaries (other than MEI), which subsidiaries also guaranteed the loans. Except as described below in connection with the Additional Availability, amounts outstanding under the Prior Credit Facility bore interest at a rate of 18% per annum, with interest payable on the last day of each of our fiscal quarters. We would have been required to pay the outstanding balance of the loan in full on the maturity date; however, beginning with the fiscal quarter ending July 31, 2013, if requested by Apollo (at the direction of lenders holding a majority of the commitments under the Prior Loan Agreement), we would have been required to repay up to $1,500 in principal quarterly. Such payments of principal would have been made, together with any interest due on such date, on the last day of our fiscal quarter. No such request to repay principal was made by Apollo.
	In addition, the outstanding debt includes paid in kind interest of $307 added to the principal amount as a part of the "PIK Election" as defined in the Prior Loan Agreement. In connection with the Prior Loan Agreement, we have granted Apollo a right of first refusal to provide debt financing for the acquisition, development, exploration or operation of any oil and gas related properties, including wells, during the term of the Prior Credit Facility and one year thereafter.
	The Prior Loan Agreement contained interest coverage, asset coverage, minimum gross production covenants, as well as other affirmative and negative covenants. As previously reported, these covenants were amended several times to adjust the covenant levels and the date on which compliance with the covenants would be measured, and to include our Tennessee production in the minimum production covenant. As of April 30, 2013, we were not in compliance with such covenants; however, we received a waiver of such violations from Apollo on July 11, 2013. Under the terms of the waiver, we were required to maintain compliance with the financial and production covenants on a quarterly basis commencing with the quarter ending October 31, 2013. As of October 31, 2013, we were in compliance with the asset coverage and minimum gross production covenants, but not the interest coverage ratio covenant. On December 9, 2013, we received an amendment and waiver from Apollo ("Eighth Amendment") which, among other matters, waived our non-compliance with the interest coverage ratio requirement as of October 31, 2013 and amended our next testing date for the interest coverage ratio to October 31, 2014. As we refinanced the Prior Credit Facility, we were not required to calculate compliance with the Prior Loan Agreement's financial covenants at January 31, 2014.
	On the Closing Date, we paid Apollo a non-refundable structuring fee of $2,750, payable for the benefit of the lenders, and we have agreed to pay an additional 5% fee to Apollo for the benefit of the lenders on the amount of every additional borrowing over and above the Original Availability. In addition, we paid Apollo a supplemental fee of $500 on the Closing Date and had agreed to pay another $500 fee on each anniversary of the Closing Date so long as the Prior Loan Agreement remained in effect.
	Additional compensation was due to Bristol Capital, LLC, a consultant to us, in connection with the closing of the Prior Loan Agreement. This fee was paid by issuing 312,500 shares of the Company's restricted common stock based on the amount of the Original Availability.
	We used a portion of the initial $40,000 loan made available under the Prior Credit Facility to repay in full the amounts outstanding under the Guggenheim Senior Secured Credit Facility ("Guggenheim Credit Facility") of approximately $26,200. The remaining $13,800 was used to (i) redeem our outstanding Series A Preferred Stock; (ii) pay certain outstanding payables; and (iii) pay transaction costs associated with the closing of the Prior Credit Facility, such as attorneys' fees. The February and April 2013 borrowings were used to fund our drilling projects and pay outstanding operational and general and administrative expenses otherwise permitted under the Prior Credit Facility.
	On August 5, 2013, we entered into Amendment No. 6 to the Prior Credit Facility (the “Sixth Amendment”) as modified by an Extension of Date for Prepayment of Tranche B Loan without Prepayment Premium (the "Extension Agreement"). The Amendment added the Additional Availability to the Prior Loan Agreement. This Additional Availability was drawn by us immediately and used for capital projects and working capital and was not initially subject to any pre-payment penalty, and was subject to an initial reduced interest rate of 9%. Under the terms of the Sixth Amendment as modified by the Extension Agreement, in the event that we had not repaid the entire outstanding amount of the loans made to date under the Prior Credit Facility ("Loans") on or before February 28, 2014, then the pre-payment penalty would have applied to the Additional Availability after that date and the interest rate on the Additional Availability would increase to 18%. The Sixth Amendment clarified that when and if any prepayment of the Loans is made from the proceeds of tax credits received by us under Alaska's Clear and Equitable Share program, that pre-payment would be applied pro rata to both the Additional Availability and previously drawn Loans (the "Prior Loans").
	In addition to the increase in the amounts available to be borrowed and the adjustment to the interest rate and prepayment penalties on those amounts, among other things, the Sixth Amendment: (i) clarified that the option under the Prior Loan Agreement to pay interest in-kind, rather than in cash, applied to the Prior Loans only and not the Additional Availability, (ii) established separate conditions precedent to borrowings from the Additional Availability, (iii) adjusted restrictions contained in Sections 7.10 and 7.12 of the Prior Loan Agreement, and (iv) established interpretive rules related to the repayment and pre-payment of the Loans.
	On September 20, 2013, we entered into Revised and Restated Consent and Amendment No. 7 (the "Seventh Amendment") with Apollo under the Prior Loan Agreement. The Seventh Amendment amended and made certain acknowledgments regarding certain provisions of the Prior Loan Agreement allowing for our issuance of our Series D Preferred Stock and the payment of dividends on the series. Among other things, the Seventh Amendment: (i) permitted the filing of supplementary articles amending our charter, designating the terms of the Series D Preferred Stock; (ii) clarified the treatment of the Series D Preferred Stock under the Prior Loan Agreement; (iii) so long as no default or event of default has occurred, allowed payment of dividends on our Series D Preferred Stock, our Series B Preferred Stock and our Series C Preferred Stock either out of Excluded Equity Proceeds (as defined in the Prior Loan Agreement) or during a Capital Covenant Compliance Period (as defined in the Prior Loan Agreement), provided that we are in compliance with the Capital Covenants (as defined in the Prior Loan Agreement) on a pro forma basis on the date of payment, (iv) restricted our ability to redeem the Series D Preferred Stock prior to the 30th day following Security Termination (as defined in the Prior Loan Agreement); and (v) prohibited us from modifying the terms of the Series D Preferred Stock without Apollo's prior written consent.
	The Seventh Amendment also extended the date by which certain liens must be lifted, as a result of the rescheduling of the Voorhees arbitration (see Note 13 - Litigation).
	As noted above, on February 3, 2014, we refinanced the Prior Credit Facility by entering into the New Loan Agreement among us, the Administrative Agent, and the Lenders. The New Loan Agreement provides for a $175,000 credit facility, which was fully drawn by us at closing, at an interest rate of LIBOR plus 9.75%, with a 2% LIBOR floor (see Note 15 - Subsequent Events).
	The fair value of the outstanding balance of the Prior Credit Facility was $69,042 as of January 31, 2014, as calculated using the discounted cash flows method.
	Series B Preferred Stock
	On September 24, 2012, we sold 25,750 shares of our Series B Cumulative Redeemable Preferred Stock (the "Series B Preferred Stock") to 10 accredited investors and issued those investors warrants to purchase 128,750 shares of common stock in a private offering exempt from registration under the Securities Act of 1933, as amended. We received gross proceeds of $2,575. We paid issuance costs of $167, which have been capitalized and are being amortized over the term of the instrument. The outstanding Series B Preferred Stock is classified as long-term debt, in accordance with ASC 480, "Distinguishing Liabilities from Equity." As of January 31, 2014, the fair value of Series B Preferred Stock was $2,326, as calculated using the discounted cash flow method.
	The designations, rights and preferences of the Series B Preferred Stock, include:
	•	a stated value of $100 per share and a liquidation preference equal to the stated value;
	•	the holders are not entitled to any voting rights and the shares of Series B Preferred Stock are not convertible into any other security;
	•	the holders are entitled to receive annual cumulative dividends at the rate of 12% per annum, payable in arrears semi-annually, which began on March 1, 2013;
	•	dividends will be paid in cash on each relevant dividend date provided that (i) we are in compliance with certain financial covenants (designated the "Capital Covenants") under the Prior Credit Facility or any amendments thereto, with compliance to be determined as of the most recent reporting date and, on a pro forma basis, on the dividend date, and (ii) no "Default" or "Event of Default" (as defined in the Prior Credit Facility or any amendments thereto) has occurred or is continuing on the dividend date;
	•	the shares may not be redeemed until 30 days after "Security Termination" (as defined in the Prior Credit Facility), but otherwise may be redeemed at any time by the Company, with a required redemption on the fifth anniversary of issuance or, if later, on the 30th day after Security Termination.
	On March 1, 2013, in accordance with our charter and the designations for the Series B Preferred Stock, we paid a semiannual dividend of approximately $5.16 per share on the Series B Preferred Stock.
	On July 18, 2013, our Board approved the payment of a semiannual dividend of approximately $6.05 per share, which was paid on September 3, 2013 as the regularly scheduled payment date of September 1, 2013 was not a business day. The record date was August 15, 2013.
	On January 28, 2014, our Board approved a semiannual dividend to shareholders of record at the close of business on February 17, 2014. The semiannual payment will be approximately $5.95 per share, which is equivalent to an annualized yield of 12%. The dividend was paid on March 3, 2014 as the regularly scheduled payment date of March 1, 2014 was not a business day. The record date was February 17, 2014.
	Debt Issue Costs
	As of January 31, 2014 and April 30, 2013, our unamortized deferred financing costs were $1,607 and $2,085, respectively, which relates to the Prior Credit Facility and the Series B Preferred Stock. As of January 31, 2014 and April 30, 2013, our unamortized debt discount, which relates to the Prior Credit Facility, was $3,346 and $2,581, respectively. These costs are being amortized over the term of the respective debt instruments.

Asset_Retirement_Obligations

Asset Retirement Obligations	9 Months Ended
	Jan. 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 nine months ended January 31, 2014 and 2013:
		For the Nine Months Ended January 31,
		2014			2013
	Asset retirement obligation, as of April 30	$	19,890		$	18,366
	Additions	196			—
	Settlements and adjustments	(22		)	—
	Accretion expense	903			853
	Asset retirement obligation, as of January 31	$	20,967		$	19,219
	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. At January 31, 2014 and April 30, 2013, there were no significant expenditures for abandonments.

StockBased_Compensation

Stock-Based Compensation	9 Months Ended
	Jan. 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. 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. On June 21, 2013 and July 29, 2013, our Compensation Committee approved additional grants of 350,000 shares of restricted stock and 7,299,996 options to purchase our common stock (the "Q1 Grants"). The grant of these 7,299,996 options to purchase shares of our common stock was included in certain employment agreements between the Company and certain executive officers, Scott M. Boruff, David J. Voyticky, David M. Hall, Deloy Miller and Kurt C. Yost. On March 10, 2014, these officers entered into an amendment to their employment agreements with the Company under which the 7,299,996 options to purchase shares of our common stock will no longer be granted. On October 11, 2013, the Compensation Committee approved an additional grant of 41,000 shares of restricted stock and an option to purchase 30,000 shares of our common stock (the "Q2 Grants"). On November 12, 2013, the Compensation Committee approved an option to purchase 800,000 shares of our common stock (the "Q3 Grants"). The Q1 Grants, Q2 Grants and Q3 Grants are contingent upon shareholder approval of an increase in the number of shares available under the 2011 share-based compensation plan and have not been included in our calculation of available shares. At January 31, 2014 and April 30, 2013, there were 77,078 and 329,328 additional shares available under the compensation plans, 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 nine months ended January 31, 2014 of approximately $1,343 and $4,368, respectively, and $2,549 and $7,077 for the three and nine months ended January 31, 2013, respectively. We also recognized non-employee expense related to warrants issued for the three and nine months ended January 31, 2014 of approximately $203 and $752, respectively, and $103 and $290 for the three and nine months ended January 31, 2013, respectively.
	The following table summarizes stock options and warrants activity for the nine months ended January 31, 2014:
		For the Nine Months Ended
		January 31, 2014
		Number of Options and Warrants		Weighted Average Exercise Price
	Beginning balance at April 30	14,403,847		$	4.61
	Granted	932,500		5.5
	Exercised	(1,581,654	)	2.84
	Canceled	(58,346	)	4.12
	Ending balance	13,696,347		4.87
	Options exercisable at January 31	10,593,495		$	4.7
	The following table summarizes stock options and warrants outstanding, including exercisable shares at January 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		1,606,400		1.4	$	0.72	1,606,400	$	0.72
	$2.00 to $4.99		1,783,000		5.7	3.55		1,263,485	3.3
	$5.25 to $5.53		3,936,947		2.7	5.32		2,636,947	5.32
	$5.89 to $5.94		3,295,000		6.6	5.92		2,936,663	5.93
	$6.00 to $6.94		3,075,000		2	6.12		2,150,000	6.08
			13,696,347		3.7	$	4.87	10,593,495	$	4.7
	The following table summarizes restricted stock activity for the nine months ended January 31, 2014:
		For the Nine Months Ended
		January 31, 2014
	Unvested at April 30	591,030
	Granted	—
	Vested	(220,849	)
	Forfeited	(12,750	)
	Unvested at January 31	357,431

Stockholders_Equity

Stockholders' Equity	9 Months Ended
	Jan. 31, 2014
Stockholders' Equity Note [Abstract]	'
Stockholders' Equity	'
	STOCKHOLDERS' EQUITY
	Common Stock
	At January 31, 2014, we had 45,231,447 shares of common stock outstanding. We issued 1,786,753 shares during the nine months ended January 31, 2014, of which 205,099 shares were issued to employees for compensation, and 1,581,654 shares were related to the exercise of equity rights.
	At January 31, 2013, we had 43,371,694 shares of common stock outstanding. We issued 2,284,943 shares during the nine months ended January 31, 2013, of which 312,500 shares were issued to Bristol Capital, LLC as payment for fees related to the closing of our credit facility, 454,665 shares were issued to employees and non-employees for compensation, 178,800 shares were issued for the settlement of an obligation, 14,000 shares were issued for oil and gas leases, and 1,286,001 shares were related to the exercise of equity rights.
	Series C Preferred Stock
	On September 28, 2012, we sold 685,000 shares of the Company's newly designated 10.75% Series C Cumulative Redeemable Preferred Stock (the "Series C Preferred Stock"). These securities are registered for sale to the public pursuant to a prospectus, dated September 18, 2012, a prospectus supplement dated September 28, 2012, and the Company's registration statement on Form S-3 (Registration No. 333-183750), which was declared effective by the SEC on September 18, 2012.  The shares were offered to the public at $23.00 per share for gross proceeds of $15,755.  We incurred issuance costs of $1,335, yielding net proceeds of $14,420.
	On October 12, 2012, we entered into an At Market Issuance Sales Agreement ("Series C ATM Agreement") with MLV & Co. LLC ("MLV"). The Series C ATM Agreement contemplates periodic sales by MLV of our Series C Preferred Stock as and when directed by the Company. These securities are registered for sale to the public pursuant to a prospectus, dated September 18, 2012, a prospectus supplement dated October 12, 2012, and the Company's registration statement on Form S-3 (Registration No. 333-183750) which was declared effective by the SEC on September 18, 2012. On and after October 12, 2012 and through January 31, 2014, we sold 780,067 shares of Series C Preferred Stock under the Series C ATM Agreement and related prospectus supplement at prices ranging from $21.48 per share to $26.71 per share. We received gross proceeds of $17,710 and incurred issuance costs of $620, yielding net proceeds of $17,090.
	On February 12, 2013, we entered into an Underwriting Agreement with MLV as representative for a group of underwriters for a follow-on "best efforts" offering of our Series C Preferred Stock. We sold an additional 625,000 shares of the Series C Preferred Stock in this offering at a price of $22.90 per share. We received gross proceeds of $14,312 and incurred issuance costs of $1,052, yielding net proceeds of $13,260 in connection with the offering. These securities are registered for sale to the public pursuant to a prospectus, dated September 18, 2012, a prospectus supplement dated February 13, 2013, and the Company's registration statement on Form S-3 (Registration No. 333-183750) which was declared effective by the SEC on September 18, 2012.
	On May 7, 2013, we entered into an Underwriting Agreement with MLV as representative for a group of underwriters for a follow-on "best efforts" offering of our Series C Preferred Stock. We sold an additional 500,000 shares of our Series C Preferred Stock, at a price of $22.25 per share. We received gross proceeds of $11,125 and incurred issuance costs of $805, yielding net proceeds of $10,320. These securities are registered for sale to the public pursuant to a prospectus, dated September 18, 2012, a prospectus supplement dated May 7, 2013, and the Company's registration statement on Form S-3 (Registration No. 333-183750) which was declared effective by the SEC on September 18, 2012.
	On June 27, 2013, we entered into an Underwriting Agreement with MLV as representative for a group of underwriters for a follow-on "best efforts" offering of our Series C Preferred Stock. We sold an additional 335,000 shares of our Series C Preferred Stock, at a price of $21.50 per share. We received gross proceeds of $7,203 and incurred issuance costs of $547, yielding net proceeds of $6,656. These securities are registered for sale to the public pursuant to a prospectus, dated September 18, 2012, a prospectus supplement dated June 28, 2013, and the Company's registration statement on Form S-3 (Registration No. 333-183750) which was declared effective by the SEC on September 18, 2012.
	The Series C Preferred Stock is classified as temporary equity in accordance with ASC 480 and is being accreted to redemption value through the earliest repayment date of November 1, 2017, which resulted in accretion of $1,796 during the nine months ended January 31, 2014. The fair value of the Series C Preferred Stock was $79,942 as of January 31, 2014, based on the closing price on that date. The designations, rights and preferences of the Series C Preferred Stock include:
	•	The holders are entitled to receive a 10.75% per annum cumulative quarterly dividend, on March 1, June 1, September 1, and December 1, payable in cash on each dividend date unless the Company is prohibited by making such payment pursuant to the terms of any agreement of the Company (including any other class or series of equity securities or any agreement related to indebtedness);
	•	The dividend may increase to a penalty rate of 12.75% if we fail to (A) pay dividends for four or more quarterly dividend periods, whether or not consecutive, or (B) maintain the listing of our Series C Preferred Stock on a national securities exchange (the events listed in clauses (A) and (B) being "Penalty Events");
	•	There is no mandatory redemption or stated maturity with respect to the Series C Preferred Stock, and it is not redeemable prior to November 1, 2017 unless: (A) there is a change in control and redemption occurs pursuant to a special right of redemption related to that change in control or (B) the Closing Bid Price of our common stock has equaled or exceeded the conversion price initially set at $10.00 per share by 150% for at least 20 trading days in any 30 consecutive trading day period (a "Market Trigger");
	•	The redemption price is $25.00 per share plus any accrued and unpaid dividends;
	•	Liquidation preference is $25.00 per share plus any accrued and unpaid dividends;
	•	The Series C Preferred Stock is senior to all our other securities except our Series B Preferred Stock, which is senior to the Series C Preferred Stock, and ranks on parity with our Series D Preferred Stock (as defined below);
	•	There is a general conversion right with respect to the Series C Preferred Stock with an initial conversion price of $10.00 per share, a special conversion right upon a change in control, and a market trigger conversion at our option in the event of a Market Trigger;
	•	The Series C Preferred Stock has been listed on the NYSE and is registered under our universal shelf; and
	•	Holders of the Series C Preferred Stock have no voting rights, except: 1) as otherwise required by law; 2) with respect to any proposal to (A) create, authorize or increase the authorized or issued amount of any class or series of our equity securities which rank senior to the Series C Preferred Stock or (B) amend, alter or repeal any provision of our charter, as amended, in a manner which materially and adversely affects any right, preference, privilege or voting power of the holders of the Series C Preferred Stock; and 3) the holders of the Series C Preferred Stock will have the right to elect two directors to our board of directors upon the occurrence of a Penalty Event.
	On April 30, 2013, our Board of Directors declared a dividend of approximately $0.67 per share on our Series C Preferred Stock which was paid on the next regularly scheduled dividend payment date of June 3, 2013, in accordance with the terms of our charter, as June 1, 2013 was not a business day. The dividend payment is equivalent to an annualized 10.75% per share, based on the $25.00 per share stated liquidation preference for the Series C Preferred Stock, accruing from March 2013 through May 2013. The record date was May 15, 2013.
	On July 18, 2013, our Board of Directors declared a dividend of approximately $0.67 per share on our Series C Preferred Stock which was paid on the next regularly scheduled dividend payment date of September 3, 2013, in accordance with the terms of our charter, as September 1, 2013 was not a business day. The dividend payment is equivalent to an annualized 10.75% per share, based on the $25.00 per share stated liquidation preference for the Series C Preferred Stock, accruing from June 2013 through August 2013. The record date was August 16, 2013.
	On October 17, 2013, our Board of Directors declared a dividend of approximately $0.67 per share on our Series C Preferred Stock which was paid on the next regularly scheduled dividend payment date of December 2, 2013, in accordance with the terms of our charter, as December 1, 2013 was not a business day. The dividend payment is equivalent to an annualized 10.75% per share, based on the $25.00 per share stated liquidation preference for the Series C Preferred Stock, accruing from September 2013 through November 2013. The record date was November 15, 2013.
	On January 28, 2014, our Board of Directors declared a dividend of approximately $0.67 per share on our Series C Preferred Stock which was paid on the next regularly scheduled dividend payment date of March 3, 2014, in accordance with the terms of our charter, as March 1, 2014 was not a business day. The dividend payment is equivalent to an annualized 10.75% per share, based on the $25.00 per share stated liquidation preference for the Series C Preferred Stock, accruing from December 2014 through February 2014. The record date was February 17, 2014.
	Series D Preferred Stock
	On September 30, 2013, we sold 1,000,000 shares of the Company's newly designated 10.5% Series D Fixed Rate/Floating Rate Cumulative Redeemable Preferred Stock (the "Series D Preferred Stock"). These securities are registered for sale to the public pursuant to a prospectus, dated September 18, 2012, a prospectus supplement dated September 26, 2013, and the Company's registration statement on Form S-3 (Registration No. 333-183750), which was declared effective by the SEC on September 18, 2012.  The shares were offered to the public at $25.00 per share for gross proceeds of $25,000.  We incurred issuance costs of $1,875, yielding net proceeds of $23,125.
	On October 17, 2013, we entered into an At Market Issuance Sales Agreement ("Series D ATM Agreement") with MLV. The Series D ATM Agreement contemplates periodic sales by MLV of our Series D Preferred Stock as and when directed by the Company. These securities are registered for sale to the public pursuant to a prospectus, dated September 18, 2012, a prospectus supplement dated October 17, 2013, and the Company's registration statement on Form S-3 (Registration No. 333-183750) which was declared effective by the SEC on September 18, 2012. On and after October 17, 2013 through January 31, 2014, we sold 69,031 shares of our Series D Preferred Stock under the Series D ATM Agreement and a prospectus supplement at prices ranging from $23.95 to $24.38 per share. We received gross proceeds of $1,667 and incurred issuance costs of $46, yielding net proceeds of $1,621 in connection with these sales.
	On January 31, 2014, pursuant to our Purchase and Sale Agreement with by and among Armstrong Cook Inlet, LLC (“Armstrong”), GMT Exploration Company, LLC, Dale Resources Alaska, LLC, Jonah Gas Company, LLC and Nerd Gas Company, LLC (collectively, the “Sellers”), we issued 213,586 shares of our Series D Preferred Stock to be held in escrow for the benefit of the Sellers, valued at approximately $5,000. For purposes of determining the number of shares of the Series D Preferred Stock, it was valued on January 31, 2014 as the average of its daily volume weighted average prices for the 10 trading days ending on and including January 31, 2014. The Series D Preferred Stock was issued in reliance on an exemption from registration under Section 4(a)(2) of the Securities Act of 1933, as amended. The Series D Preferred Stock will be held in escrow until the transfer of the equity interests in Anchor Point Energy, LLC has been completed and certain necessary regulatory approvals have been received (see Note 15 - Subsequent Events). Pursuant to the terms of our Charter applicable to the Series D Preferred Stock, we are required to pay dividends on the Series D Preferred Stock held in escrow that are payable on any dividend payment date occurring on and after declared after March 3, 2014. The dividends are also required to be paid into escrow.
	The Series D Preferred Stock is classified as permanent equity in accordance with ASC 480 and is being accreted to redemption value through the earliest redemption date of September 30, 2018, which resulted in an accretion of $139 during the nine months ended January 31, 2014. The fair value of the Series D Preferred Stock was $30,655 as of January 31, 2014, based on the closing price at that date. The designations, rights and preferences of the Series D Preferred Stock include:
	•	From the date of original issuance to (but not including) December 1, 2018 the holders are entitled to receive a 10.5% per annum cumulative quarterly dividend based on the $25.00 per share liquidation preference per annum, on March 1, June 1, September 1, and December 1, payable in cash on each dividend date unless the Company is prohibited by making such payment pursuant to the terms of any agreement of the Company (including any other class or series of equity securities or any agreement related to indebtedness);
	•	After (and including) December 1, 2018, the holders are entitled to receive a cumulative quarterly dividend at an annual rate equal to the sum of (a) Three-Month LIBOR (as defined below) as calculated on each applicable date of determination and (b) 9.073%, based on the $25.00 per share liquidation preference per annum, on March 1, June 1, September 1, and December 1, payable in cash on each dividend date unless the Company is prohibited by making such payment pursuant to the terms of any agreement of the Company (including any other class or series of equity securities or any agreement related to indebtedness);
	•	With respect to the Series D Preferred Stock, "Three-Month LIBOR" means: on any date of determination, the rate (expressed as a percentage per year) for deposits in U.S. dollars for a three-month period as appears on Bloomberg, L.P. page US0003M, as set by the British Bankers Association at 11:00 am (London time) on such date of determination;
	•	The dividend may increase by 2% to a penalty rate of (a) 12.5% (before December 1, 2018) or (b) an annual rate equal to the sum of (i) Three-Month LIBOR as calculated on each applicable date of determination and (ii)11.073%, based on the $25.00 per share liquidation preference per annum (after and including December 1, 2018) if we fail to (A) pay dividends for four or more quarterly dividend periods, whether or not consecutive, or (B) maintain the listing of our Series D Preferred Stock on a national securities exchange (the events listed in clauses (A) and (B) being "Penalty Events");
	•	There is no mandatory redemption or stated maturity with respect to the Series D Preferred Stock, and it is not redeemable prior to September 30, 2018 unless there is a change in control and redemption occurs pursuant to a special right of redemption related to that change in control;
	•	The redemption price is $25.00 per share plus any accrued and unpaid dividends;
	•	Liquidation preference is $25.00 per share plus any accrued and unpaid dividends;
	•	The Series D Preferred Stock is senior to all our other securities except our Series B Preferred Stock, which is senior to the Series D Preferred Stock, and ranks on parity with our Series C Preferred Stock;
	•	The Series D Preferred Stock has been listed on the NYSE and is registered under our universal shelf; and
	•	Holders of the Series D Preferred Stock have no voting rights, except: 1) as otherwise required by law; 2) with respect to any proposal to (A) create, authorize or increase the authorized or issued amount of any class or series of our equity securities which rank senior to the Series D Preferred Stock or (B) amend, alter or repeal any provision of our charter, as amended, in a manner which materially and adversely affects any right, preference, privilege or voting power of the holders of the Series D Preferred Stock; and 3) the holders of the Series D Preferred Stock will have the right to elect two directors to our board of directors upon the occurrence of a Penalty Event.
	On October 17, 2013, our Board of Directors declared a dividend of approximately $0.44 per share on our Series D Preferred Stock which was paid on the next regularly scheduled dividend payment date of December 2, 2013, in accordance with the terms of our charter as December 1, 2013 was not a business day. The dividend payment is equivalent to an annualized 10.5% per share, based on the $25.00 per share stated liquidation preference for the Series D Preferred Stock, accruing from issuance in September 2013 through November 2013. The record date was November 15, 2013.
	On January 28, 2014, our Board of Directors declared a dividend of approximately $0.66 per share on our Series D Preferred Stock which was paid on the next regularly scheduled dividend payment date of March 3, 2014, in accordance with the terms of our charter as March 1, 2014 was not a business day. The dividend payment is equivalent to an annualized 10.5% per share, based on the $25.00 per share stated liquidation preference for the Series D Preferred Stock, accruing from issuance in December 2013 through February 2014. The record date was February 17, 2014.

Income_Taxes

Income Taxes	9 Months Ended
	Jan. 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. We are not relying on forecasts of taxable income from other sources in concluding that no valuation allowance is needed against any of our deferred tax assets. Our provision for income taxes for the third interim reporting period in fiscal 2014 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 2014 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 nine month periods ended January 31, 2014 and January 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 January 31, 2014 is a benefit of (43.7%). The principal differences in our effective tax rate (benefit) for this period and the federal statutory rate of 35% are state income taxes, a favorable permanent difference related to mark-to-market accounting for Company warrants, and unfavorable permanent difference related to incentive stock options.  No valuation allowance was 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 January 31, 2014, and no significant payments are expected during the succeeding 12 months.

Alaska_Production_Tax_Credits

Alaska Production Tax Credits	9 Months Ended
	Jan. 31, 2014
Alaska Production Credits [Abstract]	'
Alaska Production Tax Credits	'
	ALASKA PRODUCTION TAX 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, the credit is recorded as a reduction to the related assets. For carried-forward annual loss credits, the credit is recorded as a reduction to the Alaska production tax. To the extent the credit amount exceeds the Alaska production tax, the credit is recorded as a reduction to general and administrative expenses.
	As of January 31, 2014 and April 30, 2013, the Company has reduced the basis of capitalized assets by $43,218 and $14,547 for expenditure and exploration credits, respectively. The reductions are recorded on our condensed consolidated balance sheets in oil and gas properties and equipment. As of January 31, 2014 and April 30, 2013, the Company had outstanding net receivables from the State of Alaska in the amount of $19,763 and $12,713, respectively.

Litigation

Litigation	9 Months Ended
	Jan. 31, 2014
Loss Contingency, Information about Litigation Matters [Abstract]	'
Litigation	'
	LITIGATION
	On May 11, 2011, the Court of Appeals of Tennessee at Knoxville returned its opinion in the case styled CNX Gas Company, LLC v. Miller Petroleum, Inc., et al.  As previously reported, CNX Gas Company, LLC ("CNX") commenced litigation on June 11, 2008 in the Chancery Court of Campbell County, State of Tennessee to enjoin us from assigning or conveying certain leases described in the Letter of Intent signed by CNX and our Company on May 30, 2008, to compel us to specifically perform the assignments as described in the Letter of Intent, and for damages. After the trial court granted the motion for summary judgment of the Company and other party defendants and dismissed the case, finding that there were no genuine issues of material fact and that we were entitled to judgment as a matter of law, CNX appealed.  All parties filed briefs and the Court of Appeals heard oral arguments on May 18, 2010.  In its May 11, 2011 opinion, the Court of Appeals reversed the trial court's grant of summary judgment in favor of our Company and the other party defendants, and remanded the case back to the trial court for further proceedings.  On July 28, 2011, the case was dismissed without prejudice on the motion of CNX.
	This action was revived on August 4, 2011, when a breach of contract case was filed against us in the United States District Court for the Eastern District of Tennessee.  The case, styled CNX Gas Company, LLC v. Miller Energy Resources, Inc., Chevron Appalachia, LLC as successor in interest to Atlas America, LLC, Cresta Capital Strategies, LLC and Scott Boruff, arises from the same allegations as the previous action in the state court.  The federal case seeks money damages from us for breach of contract; however, unlike the previous action, it does not seek specific performance of the assignments at issue.  The Plaintiff claims that the other defendants tortiously interfered with, or induced the breach of, the letter of intent between us and the Plaintiff.  We reached a settlement with the Plaintiff on January 24, 2014, wherein we would pay the Plaintiff $1,250 in exchange for their agreement to dismiss the case with prejudice. The Company recorded a loss of $1,250 related to this settlement in other operating expense (income), net in its consolidated statement of operations for the three and nine months ended January 31, 2014.
	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 warrant and violated a duty of good faith and fair dealing. The suit seeks 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 are 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 have filed our Answer, conducted discovery and are presently awaiting further action by the plaintiff. 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 because Mr. Stafford has made no effort whatsoever to prosecute his case since April 2, 2013, has missed filing deadlines, and has failed to appear to give his deposition both times we have noticed it. 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.
	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 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. We believe this intervention would have no effect on the outcome of the case. 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, 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. 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.
	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 alleges 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 seeks 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. We have filed a Motion to Dismiss and, in the alternative, a Motion to Stay pending the outcome of the Class Action. The Plaintiff has 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, as described in the next paragraph. The Plaintiff has also agreed to voluntarily dismiss the case in the event the plaintiff's appeal in Lukas is denied. On October 1, 2013, the Court entered an Order dismissing the 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 has.
	On August 25, 2011, and August 31, 2011, two derivative actions were filed against us and our Board of Directors and former Chief Financial Officer in the United States District Court for the Eastern District of Tennessee. These cases were consolidated into Patrick P. Lukas, derivatively on behalf Miller Energy Resources, Inc. v. Merrill A. McPeak, Scott M. Boruff, Deloy Miller, Jonathan S. Gross, Herman Gettelfinger, David Hall, Charles M. Stivers, Don A. Turkleson, and David J. Voyticky, and Miller Energy Resources, Inc., nominal defendant. As noted below, this case had been dismissed by the trial court, but that dismissal was unsuccessfully appealed by the plaintiffs. It contained substantially similar claims as Valdez. 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 failing to properly oversee and manage the company; (3) Unjust Enrichment; (4) Abuse of Control; (5) Gross Mismanagement, and; (5) Waste of Corporate Assets.  The Plaintiffs sought unspecified money damages from the individual defendants, to have us take certain actions with respect to our management, restitution to us, and the Plaintiffs' attorney fees and costs. We filed a Motion to Dismiss, which was granted on September 21, 2012. On October 16, 2012, a notice of appeal of this dismissal was filed by the Plaintiffs with the Sixth Circuit Court of Appeals. The appeal has been fully briefed, and the Court heard oral arguments on July 24, 2013. On September 19, 2013, the Court of Appeals affirmed the judgment of the District Court dismissing the case. On October 3, 2013, the Plaintiff filed a Motion for Rehearing En Banc. We filed our response to that motion on October 21, 2013, and the Court denied the motion on January 8, 2014.
	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 believe we have grounds to dispute liability with respect to some or all of these outstanding invoices. In addition, we expect to assert counterclaims against Voorhees for damages exceeding the amounts Voorhees claims are owed to it, for breach of the relevant contract by Voorhees.  The parties elected to engage a private arbitrator to settle this dispute 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 dispute is over unpaid transportation fees related to the transportation of equipment for Rig 35. These amounts were already the subject of the planned arbitration with Voorhees. As all disputes under the Rig 35 contract are subject to mandatory arbitration, we filed a motion to compel arbitration, which was granted. We are currently in settlement discussions and have postponed the arbitration as we seek a settlement. We believe that any loss would be limited to the payment of the outstanding invoices of approximately $531, plus the cost of defense.
	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 implied warranty of merchantability, breach of 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 consolidated balance sheet.
	On February 7, 2014, we were served with a lawsuit filed by Vulcan Capital Corporation 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 Plaintiff had with PlainsCapital Bank wherein Plaintiff 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 Plaintiff’s default of the loan agreement, PlainsCapital 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 are preparing to file a responsive pleading. 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.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Jan. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	COMMITMENTS AND CONTINGENCIES
	On November 5, 2009, CIE entered into an Assignment Oversight Agreement ("AOA") with the Alaska Department of Natural Resources ("Alaska DNR") which set out certain terms under which the Alaska DNR would approve the transfer of oil and gas leases owned by the State of Alaska from Pacific Energy to CIE. This agreement remains in place following our acquisition of CIE in December 2009. Generally, the agreement requires CIE to provide the Alaska DNR with additional information and oversight authority to ensure that CIE is acting diligently to develop the oil and gas from the Redoubt Unit and West McArthur River Unit ("WMRU"). Under the terms of the AOA, until the Alaska DNR determines that CIE has completed certain development and operational commitments relating to the WMRU and Redoubt Units, CIE must do the following, in addition to the normal requirements under the terms of the leases:
	•	file a quarterly summary of expenditures by oil and gas field, tied to objectives in CIE's business plan and plan of development previously presented to the Alaska DNR,
	•	meet monthly with the Alaska DNR to provide an update on operations and progress towards meeting these objectives,
	•	notify the Alaska DNR 10 days prior to commitment when CIE is preparing to spend funds on a purchase, project or item relating to the WMRU or Redoubt Unit Leases of more than $5,000,
	•	annually submit a new plan of development for the Alaska DNR's approval.
	The AOA required CIE to demonstrate funding commitments of $5,150 to support the redevelopment of the WMRU and an estimated $31,000 to support the development of the Redoubt Unit. The Company believes it has adequately fulfilled these commitments.
	The AOA prohibited CIE from using proceeds from operations at the WMRU or Redoubt Unit for non-core oil and gas activities, or activities unrelated to the WMRU or Redoubt Unit, without the prior written approval of the Alaska DNR until the parties mutually agreed that the full dismantlement obligation under the assigned leases was funded.
	On March 11, 2011, the Company entered into a Performance Bond Agreement under its AOA with the state of Alaska. Under the Performance Bond Agreement, the Company is required to post a total bond of $18,000 for the dismantling and abandonment of the properties. As agreed with the state of Alaska, the Performance Bond Agreement fulfills our commitment under the AOA to fund the full dismantlement costs with respect to our onshore and offshore assets. The Performance Bond Agreement also stipulated that funds held by the state in an escrow account will be credited towards the $18,000.
	Failure to submit the information required by the AOA would constitute a default under the AOA. If the default could not be cured within 30 days, the leases would be subject to termination by the Alaska DNR.
	Under the terms of the Performance Bond Agreement, the Company is obligated to fund an additional $12,000 towards the bond in addition to the amount held by the state in the escrow account. As of January 31, 2014, $1,000 of this amount has been funded. The remaining $11,000 (subject to annual inflation adjustments) will be funded through annual payments as follows:
	1-Jul-14		$	1,500
	1-Jul-15		2,000
	1-Jul-16		2,500
	1-Jul-17		2,000
	1-Jul-18		1,500
	1-Jul-19		1,500
			$	11,000

Subsequent_Events

Subsequent Events	9 Months Ended
	Jan. 31, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	SUBSEQUENT EVENTS
	Repayment of MEI Loans
	On February 3, 2014, we repaid all obligations under the First Secured Promissory Note dated as of November 1, 2009, a Second Secured Promissory Note dated as of December 15, 2009, a Third Secured Promissory Note dated as of May 15, 2010, and a Loan and Security Agreement dated as of March 19, 2010 (as amended, supplemented or otherwise modified prior to the date hereof, the "MEI Loan Documents"), by and among Miller Energy Income 2009-A, LP, a Delaware limited partnership ("MEI") and us. The MEI Loan Documents have terminated.
	Prepayment of Prior Credit Facility
	On February 3, 2014, we repaid in full the loans outstanding under the Prior Loan Agreement with Apollo, as administrative agent and lender, as amended from time to time, which provided for a credit facility of up to $100,000 (the "Prior Credit Facility") with a borrowing base of $55,000 and an Additional Availability allowing for $20,000 in loans. The availability under the Prior Credit Facility had been fully drawn by us. The terms of the Prior Credit Facility were amended and restated in their entirety in connection with New Credit Facility described below and, except to the extent incorporated into the New Credit Facility, the terms of the Prior Credit Facility are superseded and without further effect.
	As a result of the prepayment of the Prior Credit Facility, we owed Apollo a prepayment and extension fee of $9,223 (the “Prepayment Fee”) in connection with the termination and early repayment of borrowings under the Prior Credit Facility. Pursuant to a letter agreement entered into by the Company and Apollo, the Prepayment Fee shall be paid to Apollo in four equal installments of approximately $2,306 on the last day of each calendar quarter, commencing June 30, 2014.
	Amendment and Restatement of Prior Credit Facility
	On February 3, 2014, (the "Closing Date"), we entered into New Loan Agreement, among us, as borrower, Apollo, as administrative agent and the lenders from time to time party thereto.
	The New Loan Agreement provides for a $175,000 term credit facility (the "New 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. Amounts outstanding under the New Credit Facility bear interest at a rate of LIBOR plus 9.75%, subject to a 2% LIBOR floor. The New Credit Facility permits 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 New Credit Facility will become a second-lien credit facility. The New Credit Facility carries a four year maturity, which may be extended by up to an additional year as necessary so that it matures at least six months after the maturity date of the first lien revolving credit facility, if put in place. The New Credit Facility contains customary second lien covenants, including a leverage ratio, interest coverage ratio, current ratio, asset coverage ratio, minimum gross production and change of management control covenants. Subject to certain conditions contained in the New Loan Agreement, the New Credit Facility also allows for us to implement a discretionary share repurchase plan on terms and conditions reasonably satisfactory to the Administrative Agent and the Lenders.
	The New Loan Agreement contemplates and allows us to seek and put in place a new, first priority, credit facility ranking senior to the New Credit Facility (a "Future Credit Facility") subject to certain terms and conditions set forth in the New Loan Agreement.
	We used $75,300 of the proceeds drawn under the New Credit Facility to refinance the Prior Credit Facility with Apollo and $56,975 to finance the acquisition of the North Fork Unit (as described below). In addition, $3,800 was used to retire the obligations owed under the MEI Loan Documents. The remainder of the proceeds from the New Credit Facility will be used for general corporate purposes.
	On the Closing Date, in connection with the New Credit Facility, we, along with all of our consolidated subsidiaries (other than MEI), entered into an Amended and Restated Guarantee and Collateral Agreement (the "Guarantee") with Apollo, for the benefit of the lenders from time to time party to the New Loan Agreement. Under the terms of the Guarantee and related security documents each of our consolidated subsidiaries (other than MEI) have guaranteed our obligations under the New 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 New Credit Facility.
	The foregoing description is qualified in its entirety by reference to the full text of the New Loan Agreement which was filed as Exhibit 10.01 to a Current Report on Form 8-K on February 6, 2014 and the Guarantee and Collateral Agreement which was filed as Exhibit 10.02 thereto.
	North Fork Unit Acquisition Agreement
	On November 22, 2013, CIE entered into a purchase and sale agreement by and among Armstrong Cook Inlet, LLC (“Armstrong”), GMT Exploration Company, LLC, Dale Resources Alaska, LLC, Jonah Gas Company, LLC and Nerd Gas Company, LLC (together, the “North Fork Sellers”) and CIE (the “North Fork Purchase Agreement”). Pursuant to the North Fork Purchase Agreement, CIE acquired (i) a 100% working interest in six natural gas wells and related leases (consisting of approximately 15,465 net acres) referred to as the "North Fork Unit" in the Cook Inlet region of the State of Alaska, together with other associated rights, interests and assets (collectively, the "North Fork Properties") and (ii) all the issued and outstanding membership interests (the "Anchor Point Equity") of Anchor Point Energy, LLC, a limited liability company owning certain pipeline facilities and related assets which service the North Fork Properties, for $59,975 in cash, subject to certain adjustments described below and $5,000 of the Company's Series D Preferred Stock (collectively, the "North Fork Acquisition").
	The acquisition of the North Fork Properties closed on February 4, 2014 and the proposed acquisition of the Anchor Point Equity will close upon receiving approval from the Regulatory Commission of Alaska ("RCA Approval"), subject to customary closing conditions. Upon the closing of the North Fork Properties acquisition, the portion of consideration consisting of Series D Preferred Stock and assignment of Anchor Point Equity was deposited into an escrow account. These will be disbursed upon the closure of the Anchor Point Equity acquisition pursuant to the terms of the North Fork Purchase Agreement.
	The purchase of both the North Fork Properties and Anchor Point Equity will be accounted for as required by ASC 850, "Business Combinations." Under ASC 805, we are required to allocate the purchase price to tangible and identifiable intangible assets acquired and liabilities assumed based on their fair values at the respective closing dates. Any excess of the purchase price over those fair values is recorded as goodwill. We are in the process of valuing the assets acquired and liabilities assumed in the North Fork Properties acquisition. Disclosures required by ASC 805 will be provided when the initial accounting for the acquisitions is complete.
	Payment of Dividends
	On March 3, 2014, we paid a semiannual dividend of approximately $5.95 per share on the Series B Preferred Stock. The dividend payment is equivalent to an annualized yield of 12% per share, based on the $100.00 per share stated liquidation preference, accruing from September 1, 2013 through February 28, 2014. The record date was February 17, 2014.
	On March 3, 2014, we paid a quarterly dividend of approximately $0.67 per share on the Series C Preferred Stock. The dividend payment is equivalent to an annualized 10.75% per share, based on the $25.00 per share stated liquidation preference, accruing from December 1, 2013 through February 28, 2014. The record date was February 17, 2014.
	On March 3, 2014, we paid a quarterly dividend of approximately $0.66 per share on the Series D Preferred Stock. The dividend payment is equivalent to an annualized 10.5% per share, based on the $25.00 per share stated liquidation preference, accruing from issuance in December 1, 2013 through February 28, 2014. The record date was February 17, 2014.
	Series D Preferred Stock
	Pursuant to our Series D ATM Agreement with MLV, between January 31, 2014 and March 5, 2014, we offered and sold an additional 1,417 shares of our Series D Preferred Stock, at a price of $24.00 per share.  We received gross proceeds of $34 and incurred issuance costs of $1, yielding net proceeds of $33. These securities are registered for sale to the public pursuant to a prospectus, dated September 19, 2012, a prospectus supplement dated October 17, 2013, and the Company's registration statement on Form S-3 (Registration No. 333-183750) which was declared effective by the SEC on September 18, 2012.
	Appointment of John M. Brawley as Chief Financial Officer
	On February 12, 2014, our Board of Directors appointed Mr. John Brawley, 31, as our Chief Financial Officer. Mr. Brawley, through his consulting company, was previously a consultant for us, starting in November 2013. From 2010 to 2013 Mr. Brawley worked for Guggenheim Partners, LLC, a diversified asset management firm, where he oversaw their mezzanine energy portfolio as the co-head of the Houston office and provided energy expertise for Guggenheim's high yield and syndicated loan portfolios. Prior to Guggenheim Partners, LLC, Mr. Brawley worked directly for the CFO of ATP Oil & Gas as a consultant from 2006 to 2010, and was a financial analyst at Lehman Brothers in their energy investment banking practice in 2006. Mr. Brawley received a B.A. in Economics and Biological Sciences and an M.B.A, with a concentration in Accounting and Finance, from Rice University.
	We entered into an employment agreement with Mr. Brawley, dated as of February 12, 2014, extending until November 12, 2016, under which Mr. Brawley will receive an annual salary of $350. The Board also granted Mr. Brawley 35,000 shares of restricted stock contingent on a shareholder approval of an increase in the number of shares available under the 2011 Equity Compensation Plan (the "2011 Plan") adequate to cover this grant of restricted stock. In addition, in connection with Mr. Brawley’s engagement as a consultant on November 12, 2013, the Compensation Committee previously granted an option (the “Option”) to purchase 800,000 shares of our common stock, vesting as follows: 300,000 shares vesting on May 12, 2014, 250,000 shares vesting on November 12, 2015, and 250,000 shares vesting on November 12, 2016. This Option is also contingent upon shareholder approval of an increase in the number of shares available under the 2011 Plan adequate to cover the grant of the Option. As the Option was previously granted to Mr. Brawley’s consulting company in connection with his consulting work, that Option is being assigned with the consent of our Board of Directors and the Compensation Committee of the Board. The Option’s strike price is $6.11 per share, which was the closing price of our common stock on the New York Stock Exchange on November 12, 2013, which was when the Committee granted the Option as well as the date Mr. Brawley began rendering consulting services to us.
	Also on February 12, 2014, the Company's Board of Directors approved a change in title for Mr. David J. Voyticky to President as he had previously held the title of President and Acting Chief Financial Officer.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Jan. 31, 2014
Accounting Policies [Abstract]	'
Principles of Consolidation	'
	Principles of Consolidation
	The accompanying condensed consolidated financial statements include our consolidated accounts, including the accounts of the Company, 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.
Restricted Cash	'
	Restricted Cash
	As of January 31, 2014 and April 30, 2013, current restricted cash includes $3,447 and $7,144, respectively, of cash temporarily held in an account that is controlled by our lender. Current restricted cash balances also include amounts held in escrow to secure Company related credit cards and certain amounts held for and to be paid out to working interest owners. Non-current restricted cash balances include amounts held in escrow to provide for the future plugging and abandonment of wells, the possible dismantling of our off-shore platform, performance bonds and general liability bonds.
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. No impairment of proved properties was recognized during the nine months ended January 31, 2014 or January 31, 2013.
	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. During the nine months ended January 31, 2014 our condensed consolidated statement of operations includes $157 related to impairment of certain unproved properties and $625 in seismic and delay rentals incurred in the Cook Inlet region. We had $4 in exploration and abandonment expenses in the Appalachian region during the nine months ended January 31, 2014.
Equipment	'
	Equipment
	Equipment includes drilling rigs, automobiles, trucks, an airplane, office furniture, computer equipment, and buildings. These items are recorded at cost and are depreciated on the straight-line method based on expected lives of the individual assets or group of assets, which range from five to forty years.
	Equipment is reviewed for impairment when facts and circumstances indicate that book values may not be recoverable. In performing this review, an undiscounted cash flow test is performed at the lowest level for which identifiable cash flows are independent of cash flows from other assets. If the sum of the undiscounted estimated future net cash flows is less than the net book value of the property, an impairment loss is recognized for the excess, if any, of the property's net book value over its estimated fair value.
Investments	'
	Investments
	On June 24, 2011, we acquired a 48% minority interest in Pellissippi Pointe I, LLC and Pellissippi Pointe II, LLC (the "Pellissippi Pointe" entities or "investee") for total cash consideration of $400. In connection with the transaction, we executed a five-year lease agreement with the investee and relocated our corporate offices to the new facility on November 7, 2011. Since we do not exercise control over the financial and operating decisions made by the investee, we have accounted for these investments using the equity method. These investments are reflected in other assets in the accompanying condensed consolidated balance sheets.
Guarantees	'
	Guarantees
	On July 12, 2012, we signed a direct guarantee for 55% of the $5,074 outstanding loan obligations with FSG Bank for the Pellissippi Pointe equity investment. The Company's guarantee is included within the scope of Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") 460, "Guarantees" and was recorded at the estimated fair value of $250; such amount is included in accrued expenses on our condensed consolidated balance sheet as of January 31, 2014 and is being amortized over the five-year life of the guarantee. The fair value was calculated using the income approach and the estimated default rate was determined by obtaining the average cumulative issuer-weighted corporate default rate based on the credit rating of Pellissippi Pointe and the term of the underlying loan obligations. The default rates are published by Moody's Investors Service. To the extent we are required to make payments under the guarantee, we will record the differences between the liability and the associated payments in earnings. At January 31, 2014, our maximum potential undiscounted payment under this arrangement is $2,791 plus additional lender's costs.
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 January 31, 2014 our cumulative dividends were $7,573.
New Accounting Pronouncements	'
	New Accounting Pronouncements
	In December 2011, the FASB issued Accounting Standards Update ("ASU") 2011-11, "Disclosures about Offsetting Assets and Liabilities," which increases disclosures about offsetting assets and liabilities. The new disclosures are required to enable users of financial statements to understand significant quantitative differences in balance sheets prepared under GAAP and International Financial Reporting Standards ("IFRS") related to the offsetting of financial instruments. The existing GAAP guidance allowing balance sheet offsetting, including industry-specific guidance, remains unchanged. The guidance in ASU 2011-11 was effective for annual and interim reporting periods beginning on or after January 1, 2013. The disclosures should be applied retrospectively for all prior periods presented. We have adopted ASU 2011-11; however, it did not have a material impact to 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.

Organization_and_Basis_of_Pres1

Organization and Basis of Presentation (Tables)	9 Months Ended
	Jan. 31, 2014
Other Current Assets [Member]	'
Schedule of Error Corrections and Prior Period Adjustments	'
	We reclassified a $5,305 contra asset related to Alaska production tax credits from oil and gas properties to equipment. The credits that resulted in the recognition of the contra asset related to our drilling rigs, the costs of which are classified in equipment. We have determined the reclassification to be immaterial to the prior period consolidated balance sheet taken as a whole. This error did not have an impact on the prior period consolidated statements of operations, equity or cash flows.
		As Presented					As Adjusted
		30-Apr-13		Reclassifications			30-Apr-13
	Oil and gas properties, net	$	486,009	$	5,305		$	491,314
	Equipment, net	$	42,876	$	(5,305	)	$	37,571
Other Noncurrent Liabilities [Member]	'
Schedule of Error Corrections and Prior Period Adjustments	'
	In addition, we reclassified certain costs related to the issuance of debt under our Prior Credit Facility that were paid to our lender. The costs were initially recorded and reflected as deferred financing costs on our condensed consolidated balance sheet and have been reclassified as a debt discount. We have determined the reclassification to be immaterial to the prior period consolidated balance sheet taken as a whole. This error did not have an impact on the prior period consolidated statements of operations, equity or cash flows.
		As Presented					As Adjusted
		30-Apr-13		Reclassifications			30-Apr-13
	Deferred financing costs, net	$	4,666	$	(2,581	)	$	2,085
	Long-term debt, less current portion	$	51,559	$	(2,581	)	$	48,978

Oil_and_Gas_Properties_and_Equ1

Oil and Gas Properties and Equipment (Tables)	9 Months Ended
	Jan. 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:
		January 31,			April 30,
		2014			2013
	Property costs
	Proved property	$	389,810		$	332,241
	Unproved property	235,134			196,500
	Total property costs	624,944			528,741
	Less: Accumulated depletion	(56,136		)	(37,427		)
	Oil and gas properties, net	$	568,808		$	491,314
Property, Plant and Equipment	'
	Equipment is summarized as follows:
		January 31,			April 30,
		2014			2013
	Machinery and equipment	$	7,748		$	7,413
	Vehicles	1,877			1,851
	Aircraft	476			476
	Buildings	2,725			2,725
	Office equipment	812			759
	Leasehold improvements	485			482
	Drilling rigs	30,117			30,117
		44,240			43,823
	Less: Accumulated depreciation	(9,380		)	(6,252		)
	Equipment, net	$	34,860		$	37,571
Depreciation, Depletion, and Amortization	'
	Depreciation, depletion and amortization consisted of the following:
		For the Nine Months Ended January 31,
		2014			2013
	Depletion of oil and gas related assets	$	19,158		$	7,240
	Depreciation and amortization of equipment	3,194			2,288
	Total	$	22,352		$	9,528

Derivative_Instruments_and_Fai1

Derivative Instruments and Fair Value Measurements (Tables)	9 Months Ended
	Jan. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of Derivative Instruments	'
	As of January 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
	2014		191,400			$	102.92
	2015		785,000			100.58
	2016		787,600			95.75
	2017		232,600			94.27
Schedule of Derivative Assets and Liabilities at Fair Value	'
	As of January 31, 2014 and April 30, 2013, the fair market value of our derivative liabilities was as follows:
			Asset Derivatives											Liability Derivatives
			January 31, 2014						April 30, 2013					January 31, 2014				April 30, 2013
	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		$	564			Prepaid expenses and other		$	—		Current portion of derivative instruments	$	(1,758	)	Current portion of derivative instruments	$	(842	)
	Commodity derivatives		Other assets		680				Other assets		—			Long-term portion of derivative instruments	(3,152		)	Long-term portion of derivative instruments	—
	Total derivatives not designated as hedging instruments under ASC 815				$	1,244					$	—			$	(4,910	)		$	(842	)
Offsetting Assets and Liabilities	'
	The following table presents our gross and net derivative assets and liabilities:
		Gross Amount				Netting Adjustments (a)				Net Amount Presented on Balance Sheet
	January 31, 2014
	Derivative assets with right of offset or master netting agreements	$	1,244			$	—			$	1,244
	Derivative liabilities with right of offset or master netting agreements	$	(4,910	)		$	—			$	(4,910	)
	April 30, 2013
	Derivative assets with right of offset or master netting agreements	$	—			$	—			$	—
	Derivative liabilities with right of offset or master netting agreements	$	(842	)		$	—			$	(842	)
	—————————
	(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 January 31,								For the Nine Months Ended January 31,
		2014				2013				2014			2013
	Gain (loss) on derivatives, net	$	1,677			$	(1,681	)		$	(5,589	)	$	5,215
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	'
	The following table presents, by level within the fair value hierarchy, the Company's assets and liabilities that are measured at fair value on a recurring basis as of January 31, 2014 and April 30, 2013. The carrying amounts reported in the condensed consolidated balance sheets for cash and cash equivalents, restricted cash, accounts receivable and accounts payable approximate fair value due to the nature of the instrument and/or the short-term maturity of these instruments.
		Fair Value Measurements
	At January 31, 2014	Level 1				Level 2				Level 3
	Commodity derivative asset	$	—			$	1,244			$	—
	Commodity derivative liability	$	—			$	(4,910	)		$	—
	Total	$	—			$	(3,666	)		$	—
	At April 30, 2013
	Commodity derivative asset	$	—			$	—			$	—
	Commodity derivative liability	$	—			$	(842	)		$	—
	Total	$	—			$	(842	)		$	—

Debt_Tables

Debt (Tables)	9 Months Ended
	Jan. 31, 2014
Debt Disclosure [Abstract]	'
Schedule of Long-term Debt Instruments	'
	As of January 31, 2014 and April 30, 2013, we had the following debt obligations reflected at their respective carrying values on our condensed consolidated balance sheets:
		January 31,			April 30,
		2014			2013
	Apollo senior secured Credit Facility	$	75,307		$	55,307
	Debt discount related to Apollo senior secured Credit Facility	(3,346		)	(2,581		)
	Series B Preferred Stock	2,307			2,252
	Total debt obligations	$	74,268		$	54,978

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	9 Months Ended
	Jan. 31, 2014
Asset Retirement Obligation [Abstract]	'
Schedule of Asset Retirement Obligations	'
	The following table presents changes to the Company's asset retirement obligation ("ARO") liability for the nine months ended January 31, 2014 and 2013:
		For the Nine Months Ended January 31,
		2014			2013
	Asset retirement obligation, as of April 30	$	19,890		$	18,366
	Additions	196			—
	Settlements and adjustments	(22		)	—
	Accretion expense	903			853
	Asset retirement obligation, as of January 31	$	20,967		$	19,219

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	9 Months Ended
	Jan. 31, 2014
Share-based Compensation [Abstract]	'
Schedule of Share-based Compensation, Activity	'
	The following table summarizes stock options and warrants activity for the nine months ended January 31, 2014:
		For the Nine Months Ended
		January 31, 2014
		Number of Options and Warrants		Weighted Average Exercise Price
	Beginning balance at April 30	14,403,847		$	4.61
	Granted	932,500		5.5
	Exercised	(1,581,654	)	2.84
	Canceled	(58,346	)	4.12
	Ending balance	13,696,347		4.87
	Options exercisable at January 31	10,593,495		$	4.7
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 January 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		1,606,400		1.4	$	0.72	1,606,400	$	0.72
	$2.00 to $4.99		1,783,000		5.7	3.55		1,263,485	3.3
	$5.25 to $5.53		3,936,947		2.7	5.32		2,636,947	5.32
	$5.89 to $5.94		3,295,000		6.6	5.92		2,936,663	5.93
	$6.00 to $6.94		3,075,000		2	6.12		2,150,000	6.08
			13,696,347		3.7	$	4.87	10,593,495	$	4.7
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	'
	The following table summarizes restricted stock activity for the nine months ended January 31, 2014:
		For the Nine Months Ended
		January 31, 2014
	Unvested at April 30	591,030
	Granted	—
	Vested	(220,849	)
	Forfeited	(12,750	)
	Unvested at January 31	357,431

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	9 Months Ended
	Jan. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Long-term Purchase Commitment	'
	Under the terms of the Performance Bond Agreement, the Company is obligated to fund an additional $12,000 towards the bond in addition to the amount held by the state in the escrow account. As of January 31, 2014, $1,000 of this amount has been funded. The remaining $11,000 (subject to annual inflation adjustments) will be funded through annual payments as follows:
	1-Jul-14	$	1,500
	1-Jul-15	2,000
	1-Jul-16	2,500
	1-Jul-17	2,000
	1-Jul-18	1,500
	1-Jul-19	1,500
		$	11,000

Organization_and_Basis_of_Pres2

Organization and Basis of Presentation (Details) (USD $)	Jan. 31, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Oil and gas properties, net	$568,808	$491,314
Equipment, net	34,860	37,571
Scenario, Previously Reported [Member]	'	'
Oil and gas properties, net	'	486,009
Equipment, net	'	42,876
Scenario, Adjustment [Member]	'	'
Oil and gas properties, net	'	5,305
Equipment, net	'	-5,305
Scenario, Actual [Member]	'	'
Oil and gas properties, net	'	491,314
Equipment, net	'	$37,571

Organization_and_Basis_of_Pres3

Organization and Basis of Presentation (Details 1) (USD $)	Jan. 31, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Deferred financing costs, net	$1,607	$2,085
Long-term debt, less current portion	74,268	48,978
Scenario, Previously Reported [Member]	'	'
Deferred financing costs, net	'	4,666
Long-term debt, less current portion	'	51,559
Scenario, Adjustment [Member]	'	'
Deferred financing costs, net	'	-2,581
Long-term debt, less current portion	'	-2,581
Scenario, Actual [Member]	'	'
Deferred financing costs, net	'	2,085
Long-term debt, less current portion	'	$48,978

Organization_and_Basis_of_Pres4

Organization and Basis of Presentation (Details Textual) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Reclassification adjustment	$5,305

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details) (USD $)	0 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Jul. 12, 2012	Jun. 24, 2011	Jan. 31, 2014	Jan. 31, 2013	Apr. 30, 2013
Restricted Cash	'	'	'	'	'
Cash controlled by lender	'	'	$3,447	'	$7,144
Oil and Gas Properties	'	'	'	'	'
Impairment of proved properties	'	'	0	0	'
Impairment of unproved properties	'	'	157	'	'
Seismic and delay rentals incurred	'	'	625	'	'
Exploration and abandonment expense	'	'	4	'	'
Investments	'	'	'	'	'
Minority interest (percent)	'	'	48.00%	'	'
Total cash consideration	'	400	'	'	'
Lease agreement (in years)	'	'5 years	'	'	'
Guarantees	'	'	'	'	'
Direct guarantee (percent)	'	'	55.00%	'	'
Loan obligaitons outstanding	5,074	'	'	'	'
Estimated fair value	250	'	'	'	'
Term of guarantee (in years)	'5 years	'	'	'	'
Maximum potential undiscounted payments	'	'	2,791	'	'
Loss Per Share	'	'	'	'	'
Cumulative dividends	'	'	$7,573	'	'

Major_Customers_and_Concentrat1

Major Customers and Concentrations of Credit Risk (Details) (USD $)	9 Months Ended		3 Months Ended	9 Months Ended		12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2014	Jan. 31, 2014	Jan. 31, 2014	Apr. 30, 2013
			Revenue [Member]	Revenue [Member]	Accounts receivable [Member]	Accounts receivable [Member]
Concentration Risk [Line Items]	'	'	'	'	'	'
Concentration risk (percent)	'	'	95.00%	93.00%	14.00%	55.00%
Credit losses	$0	$0	'	'	'	'
FDIC uninsured amount	15,677,000	'	'	'	'	'
FDIC insured amount	$250,000	'	'	'	'	'

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	9 Months Ended	12 Months Ended			3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
In Thousands, except Share data, unless otherwise specified	Jan. 31, 2014	Apr. 30, 2013	Sep. 18, 2013	31-May-10	Jan. 31, 2014	Jan. 31, 2014	Jan. 31, 2014	Jan. 31, 2014	Jan. 31, 2014	Jan. 31, 2014
				Note	H&H Industrial [Member]	H&H Industrial [Member]	Rediske Air, Inc. [Member]	Rediske Air, Inc. [Member]	William Weakley [Member]	William Weakley [Member]
Related Party Transaction [Line Items]	'	'	'	'	'	'	'	'	'	'
Amount paid to related party	'	'	'	'	$450	$1,349	'	'	$2	$2
Amount paid to former related party	'	'	'	'	'	'	281	865	'	'
Related payable recorded	36	620	'	'	'	'	'	'	'	'
Related receivable recorded	'	593	'	'	'	'	'	'	'	'
Number of secured promissory notes	'	'	'	3	'	'	'	'	'	'
Amount borrowed	'	'	'	$3,071	'	'	'	'	'	'
Ownership of consolidated entity (percent)	1.00%	'	'	'	'	'	'	'	'	'
Minimum ownership of outstanding stock (percent)	5.00%	'	'	'	'	'	'	'	'	'
Warrants issued (in shares)	'	'	300,000	'	'	'	'	'	'	'
Exercise price (in dollars per share)	'	'	6.63	'	'	'	'	'	'	'

Oil_and_Gas_Properties_and_Equ2

Oil and Gas Properties and Equipment (Details) (USD $)	Jan. 31, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Property costs	'	'
Proved property	$389,810	$332,241
Unproved property	235,134	196,500
Total property costs	624,944	528,741
Less: Accumulated depletion	-56,136	-37,427
Oil and gas properties, net	$568,808	$491,314

Oil_and_Gas_Properties_and_Equ3

Oil and Gas Properties and Equipment (Details 1) (USD $)	Jan. 31, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Equipment	'	'
Equipment, gross	$44,240	$43,823
Less: Accumulated depreciation	-9,380	-6,252
Equipment, net	34,860	37,571
Machinery and Equipment [Member]	'	'
Equipment	'	'
Equipment, gross	7,748	7,413
Vehicles [Member]	'	'
Equipment	'	'
Equipment, gross	1,877	1,851
Aircraft [Member]	'	'
Equipment	'	'
Equipment, gross	476	476
Buildings [Member]	'	'
Equipment	'	'
Equipment, gross	2,725	2,725
Office Equipment [Member]	'	'
Equipment	'	'
Equipment, gross	812	759
Leasehold Improvements [Member]	'	'
Equipment	'	'
Equipment, gross	485	482
Drilling Rigs [Member]	'	'
Equipment	'	'
Equipment, gross	$30,117	$30,117

Oil_and_Gas_Properties_and_Equ4

Oil and Gas Properties and Equipment (Details 2) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013
Property, Plant and Equipment [Abstract]	'	'
Depletion of oil and gas related assets	$19,158	$7,240
Depreciation and amortization of equipment	3,194	2,288
Total	$22,352	$9,528

Derivative_Instruments_and_Fai2

Derivative Instruments and Fair Value Measurements (Details) (Not Designated as Hedging Instrument [Member], Crude Oil [Member], Swap [Member])	9 Months Ended
	Jan. 31, 2014
	bbl
2014 [Member]	'
Derivative [Line Items]	'
Open positions (in barrels)	191,400
Weighted average fixed price (in dollars per barrel)	102.92
2015 [Member]	'
Derivative [Line Items]	'
Open positions (in barrels)	785,000
Weighted average fixed price (in dollars per barrel)	100.58
2016 [Member]	'
Derivative [Line Items]	'
Open positions (in barrels)	787,600
Weighted average fixed price (in dollars per barrel)	95.75
2017 [Member]	'
Derivative [Line Items]	'
Open positions (in barrels)	232,600
Weighted average fixed price (in dollars per barrel)	94.27

Derivative_Instruments_and_Fai3

Derivative Instruments and Fair Value Measurements (Details 1) (Not Designated as Hedging Instrument [Member], Commodity Contract [Member], USD $)	Jan. 31, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Asset derivatives	$1,244	$0
Liability derivatives	4,910	842
Prepaid Expenses and Other Current Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Asset derivatives	564	'
Other Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Asset derivatives	680	'
Current Portion of Derivative Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Liability derivatives	1,758	842
Long-term Portion of Derivative Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Liability derivatives	$3,152	'

Derivative_Instruments_and_Fai4

Derivative Instruments and Fair Value Measurements (Details 2) (Not Designated as Hedging Instrument [Member], Commodity Contract [Member], USD $)	Jan. 31, 2014		Apr. 30, 2013
In Thousands, unless otherwise specified
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member]	'		'
Derivatives, Fair Value [Line Items]	'		'
Gross amount	$1,244		$0
Netting adjustments	0	[1]	0	[1]
Net amount presented on balance sheet	1,244		0
Gross amount	-4,910		-842
Netting adjustments	0	[1]	0	[1]
Net amount presented on balance sheet	($4,910)		($842)
[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_and_Fai5

Derivative Instruments and Fair Value Measurements (Details 3) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2014	Jan. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'	'	'	'
Gain (loss) on derivatives, net	$1,677	($1,681)	($5,589)	$5,215

Derivative_Instruments_and_Fai6

Derivative Instruments and Fair Value Measurements (Details 4) (Not Designated as Hedging Instrument [Member], Commodity Contract [Member], USD $)	Jan. 31, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Derivative Instruments Hierarchy Classification	'	'
Commodity derivative asset	$1,244	$0
Commodity derivative liability	-4,910	-842
Fair Value, Measurements, Recurring [Member] | Level 2 Fair Value Measurements [Member]	'	'
Derivative Instruments Hierarchy Classification	'	'
Commodity derivative asset	1,244	'
Commodity derivative liability	-4,910	-842
Total	($3,666)	($842)

Debt_Details

Debt (Details) (USD $)	Jan. 31, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]	'	'
Apollo senior secured Credit Facility	$75,307	$55,307
Debt discount related to Apollo senior secured Credit Facility	-3,346	-2,581
Series B Preferred Stock	2,307	2,252
Total debt obligations	$74,268	$54,978

Debt_Details_Textual

Debt (Details Textual) (USD $)	0 Months Ended				9 Months Ended		0 Months Ended		0 Months Ended
	Aug. 05, 2013	Apr. 25, 2013	Feb. 07, 2013	Jun. 29, 2012	Jan. 31, 2014	Apr. 30, 2013	Feb. 03, 2014	Feb. 03, 2014	Jun. 29, 2012	Jun. 29, 2012
							Subsequent Event [Member]	London Interbank Offered Rate (LIBOR) [Member]	Line of Credit [Member]	Accounts Payable [Member]
								Subsequent Event [Member]
Line of Credit Facility [Line Items]	'	'	'	'	'	'	'	'	'	'
Credit facility	'	'	'	$100,000,000	'	'	$175,000,000	'	'	'
Borrowing base	75,000,000	'	'	55,000,000	'	'	'	'	'	'
Amount borrowed	20,000,000	10,000,000	5,000,000	40,000,000	'	'	175,000,000	'	'	'
Increase in borrowing capacity	20,000,000	'	'	'	'	'	'	'	'	'
Interest rate per annum (percent)	'	'	'	'	18.00%	'	'	'	'	'
Periodic principal payment	'	'	'	'	1,500,000	'	'	'	'	'
Capitalized interest	'	'	'	'	307,000	'	'	'	'	'
Structuring fee	'	'	'	2,750,000	'	'	'	'	'	'
Increased borrowing fee (percent)	'	'	'	5.00%	'	'	'	'	'	'
Supplemental fee	'	'	'	500,000	'	'	'	'	'	'
Annual fee	'	'	'	500,000	'	'	'	'	'	'
Additional compensation (in shares)	'	'	'	312,500	'	'	'	'	'	'
Extinguishment of debt	'	'	'	'	'	'	'	'	26,200,000	13,800,000
Temporary interest rate of New Availability (percent)	'	'	'	'	9.00%	'	'	'	'	'
Variable rate (percent)	'	'	'	'	'	'	'	9.75%	'	'
LIBOR floor rate (percent)	'	'	'	'	'	'	'	2.00%	'	'
Fair value of outstanding balance	'	'	'	'	69,042,000	'	'	'	'	'
Unamortized deferred financing costs	'	'	'	'	$1,607,000	$2,085,000	'	'	'	'

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			9 Months Ended	0 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 03, 2013	Mar. 01, 2013	Sep. 24, 2012	Jan. 31, 2014	Mar. 03, 2014
					Subsequent Event [Member]
Preferred Stock	'	'	'	'	'
Shares issued (in shares)	'	'	25,750	'	'
Common stock for purchase (in shares)	'	'	128,750	'	'
Gross proceeds	'	'	$2,575	'	'
Broker's fee	'	'	167	'	'
Fair value	'	'	'	$2,326	'
Preferred stock stated value (in dollars per share)	'	'	'	$100	'
Liquidation preference (in dollars per share)	'	'	'	$100	'
Cumulative dividend rate per annum (percent)	'	'	'	12.00%	'
Semiannual dividend paid (in dollars per share)	$6.05	$5.16	'	'	$5.95

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2014	Jan. 31, 2013
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]	'	'	'	'
Asset retirement obligation, as of April 30	'	'	$19,890	$18,366
Additions	'	'	196	'
Settlements and adjustments	'	'	-22	'
Accretion of asset retirement obligation	305	284	903	853
Asset retirement obligation, as of January 31	$20,967	$19,219	$20,967	$19,219

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	9 Months Ended
	Jan. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'
Beginning balance (in shares)	14,403,847
Beginning balance, weighted average exercise price (in dollars per share)	$4.61
Granted (in shares)	932,500
Granted, weighted average price (in dollars per share)	$5.50
Exercised (in shares)	1,581,654
Exercised, weighted average price (in dollars per share)	$2.84
Canceled (in shares)	-58,346
Canceled, weighted average price (in dollars per share)	$4.12
Ending balance (in shares)	13,696,347
Ending balance, weighted average exercise price (in dollars per share)	$4.87
Options exercisable at January 31 (in shares)	10,593,495
Options exercisable at January 31, weighted average price (in dollars per share)	$4.70

StockBased_Compensation_Detail1

Stock-Based Compensation (Details 1) (USD $)	9 Months Ended
	Jan. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	13,696,347
Weighted average remaining contractural life (in years)	'3 years 8 months 12 days
Weighted average exercise price (in dollars per share)	$4.87
Number exercisable (in shares)	10,593,495
Weighted average exercise price (in dollars per share)	$4.70
$0.01 to $1.82 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	1,606,400
Weighted average remaining contractural life (in years)	'1 year 4 months 24 days
Weighted average exercise price (in dollars per share)	$0.72
Number exercisable (in shares)	1,606,400
Weighted average exercise price (in dollars per share)	$0.72
$2.00 to $4.99 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	1,783,000
Weighted average remaining contractural life (in years)	'5 years 8 months 12 days
Weighted average exercise price (in dollars per share)	$3.55
Number exercisable (in shares)	1,263,485
Weighted average exercise price (in dollars per share)	$3.30
$5.25 to $5.53 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	3,936,947
Weighted average remaining contractural life (in years)	'2 years 8 months 12 days
Weighted average exercise price (in dollars per share)	$5.32
Number exercisable (in shares)	2,636,947
Weighted average exercise price (in dollars per share)	$5.32
$5.89 to $5.94 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	3,295,000
Weighted average remaining contractural life (in years)	'6 years 7 months 6 days
Weighted average exercise price (in dollars per share)	$5.92
Number exercisable (in shares)	2,936,663
Weighted average exercise price (in dollars per share)	$5.93
$6.00 to $6.94 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	3,075,000
Weighted average remaining contractural life (in years)	'2 years 0 months 0 days
Weighted average exercise price (in dollars per share)	$6.12
Number exercisable (in shares)	2,150,000
Weighted average exercise price (in dollars per share)	$6.08

StockBased_Compensation_Detail2

Stock-Based Compensation (Details 2) (USD $)	9 Months Ended
	Jan. 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
$5.25 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)	$5.25
Exercise price range, upper limit (in dollars per share)	$5.53
$5.89 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)	$5.89
Exercise price range, upper limit (in dollars per share)	$5.94
$6.00 to $6.94 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise price range, lower limit (in dollars per share)	$6
Exercise price range, upper limit (in dollars per share)	$6.94

StockBased_Compensation_Detail3

Stock-Based Compensation (Details 3)	9 Months Ended
	Jan. 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 (in shares)	591,030
Granted (in shares)	'
Vested (in shares)	-220,849
Forfeited (in shares)	-12,750
Unvested at January 31 (in shares)	357,431

StockBased_Compensation_Detail4

Stock-Based Compensation (Details Textual) (USD $)	3 Months Ended		9 Months Ended				0 Months Ended
In Thousands, except Share data, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2014	Jan. 31, 2013	Apr. 30, 2013	Apr. 30, 2010	Nov. 12, 2013	Oct. 11, 2013	Jul. 29, 2013	Jun. 21, 2013	Apr. 30, 2011
						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
Restricted stock pending shareholder approval (in shares)	'	'	'	'	'	'	'	41,000	'	350,000	'
Options pending shareholder approval (in shares)	'	'	'	'	'	'	800,000	30,000	7,299,996	'	'
Shares available for grant (in shares)	77,078	'	77,078	'	329,328	'	'	'	'	'	'
Employee share-based compensation expense	$1,343	$2,549	$4,368	$7,077	'	'	'	'	'	'	'
Nonemployee expense	$203	$103	$752	$290	'	'	'	'	'	'	'

Stockholders_Equity_Details

Stockholders' Equity (Details)	9 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Apr. 30, 2013
Stockholders' Equity Note [Abstract]	'	'	'
Shares outstanding (in shares)	45,231,447	43,371,694	43,444,694
Shares issued (in shares)	1,786,753	2,284,943	'
Shares issued for compensation (in shares)	205,099	454,665	'
Exercise of equity rights (in shares)	1,581,654	1,286,001	'
Shares issued as payment for fees (in shares)	'	312,500	'
Shares issued for settlement of obligation (in shares)	'	178,800	'
Shares issued for oil and gas leases (in shares)	'	14,000	'

Stockholders_Equity_Details_1

Stockholders' Equity (Details 1) (USD $)

9 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

16 Months Ended

0 Months Ended

In Thousands, except Share data, unless otherwise specified

Jan. 31, 2014

Jan. 31, 2013

Jan. 28, 2014

Dec. 02, 2013

Oct. 17, 2013

Sep. 03, 2013

Jul. 18, 2013

Jun. 27, 2013

Jun. 03, 2013

7-May-13

Apr. 30, 2013

Feb. 12, 2013

Sep. 28, 2012

Apr. 30, 2013

Jan. 31, 2014

Jan. 31, 2014

Jan. 31, 2014

Jan. 31, 2014

Mar. 03, 2014

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Subsequent Event [Member]

Minimum [Member]

Maximum [Member]

Series C Preferred Stock [Member]

Preferred Stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares issued (in shares)

'

'

780,067

'

'

'

'

335,000

'

500,000

1,454,901

625,000

685,000

1,454,901

3,069,968

3,069,968

'

'

'

Cumulative declared dividend rate per annum (percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10.75%

'

'

'

10.75%

Price per share (in dollars per share)

'

'

'

'

'

'

'

$21.50

'

$22.25

'

$22.90

$23

'

'

'

$21.48

$26.71

'

Gross proceeds

'

'

'

'

'

'

'

$7,203

'

$11,125

'

$14,312

$15,755

'

'

$17,710

'

'

'

Issuance costs

3,893

1,576

'

'

'

'

'

547

'

805

'

1,052

1,335

'

'

620

'

'

'

Net proceeds

'

'

'

'

'

'

'

6,656

'

10,320

'

13,260

14,420

'

'

17,090

'

'

'

Accretion of preferred stock

1,935

2,605

'

'

'

'

'

'

'

'

'

'

'

261

1,796

'

'

'

'

Fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$79,942

$79,942

'

'

'

Potential penalty rate (percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

12.75%

'

'

'

'

Market Trigger

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion price (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$10

$10

'

'

'

Increase in closing bid price (percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

150.00%

'

'

'

'

Trading days (in days)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'20 days

'

'

'

'

Consecutive trading day period (in days)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'30 days

'

'

'

'

Redemption price (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$25

$25

'

'

'

Liquidation preference (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$25

$25

'

'

$25

Declared dividend (in dollars per share)

'

'

$0.67

'

$0.67

'

$0.67

'

'

'

$0.67

'

'

'

'

'

'

'

'

Dividend paid (in dollars per share)

'

'

'

$0.67

'

$0.67

'

'

$0.67

'

'

'

'

'

'

'

'

'

$0.67

Stockholders_Equity_Details_2

Stockholders' Equity (Details 2) (USD $)

9 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

1 Months Ended

9 Months Ended

In Thousands, except Share data, unless otherwise specified

Jan. 31, 2014

Jan. 31, 2013

Apr. 30, 2013

Jan. 28, 2014

Dec. 02, 2013

Oct. 17, 2013

Sep. 30, 2013

Jan. 31, 2014

Jan. 31, 2014

Mar. 03, 2014

Mar. 05, 2014

Jan. 31, 2014

Jan. 31, 2014

Jan. 31, 2014

Jan. 31, 2014

Jan. 31, 2014

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]

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]

Series D Preferred Stock [Member]

Series D Preferred Stock [Member]

Series D Preferred Stock [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Before December 1, 2018 [Member]

On or After December 1, 2018 [Member]

North Fork Acquisition [Member]

Minimum [Member]

Maximum [Member]

Class of Stock [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares issued (in shares)

'

'

'

69,031

'

'

1,000,000

1,069,301

1,069,301

'

1,417

'

'

213,586

'

'

Cumulative dividend rate per annum (percent)

'

'

'

'

'

'

'

'

10.50%

10.50%

'

'

9.07%

'

'

'

Price per share (in dollars per share)

'

'

'

'

'

'

$25

'

'

'

$24

'

'

'

$23.95

$24.38

Gross proceeds

'

'

'

'

'

'

$25,000

$1,667

'

'

$34

'

'

'

'

'

Issuance costs

3,893

1,576

'

'

'

'

1,875

46

'

'

1

'

'

'

'

'

Net proceeds

'

'

'

'

'

'

23,125

1,621

'

'

33

'

'

'

'

'

Value

29,885

'

'

'

'

'

'

'

'

'

'

'

'

5,000

'

'

Accretion of Series D Preferred Stock

0

'

'

'

'

'

'

'

139

'

'

'

'

'

'

'

Fair value

'

'

'

'

'

'

'

$30,655

$30,655

'

'

'

'

'

'

'

Liquidation preference (in dollars per share)

'

'

'

'

'

'

'

$25

$25

$25

'

'

'

'

'

'

Potential increase in dividend rate (percent)

'

'

'

'

'

'

'

'

2.00%

'

'

'

'

'

'

'

Potential penalty rate (percent)

'

'

'

'

'

'

'

'

'

'

'

12.50%

11.07%

'

'

'

Redemption price (in dollars per share)

'

'

'

'

'

'

'

$25

$25

'

'

'

'

'

'

'

Declared dividend (in dollars per share)

'

'

'

$0.66

'

$0.44

'

'

'

'

'

'

'

'

'

'

Dividend paid (in dollars per share)

'

'

'

'

$0.44

'

'

'

'

$0.66

'

'

'

'

'

'

Income_Taxes_Details

Income Taxes (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2014
Income Tax Disclosure [Abstract]	'
Valuation allowance	$0
Effective tax rate (benefit) (percent)	-43.70%
Federal statutory rate (percent)	35.00%
Income taxes paid	0
Significant payments expected	$0

Alaska_Production_Tax_Credits_

Alaska Production Tax Credits (Details) (USD $)	Jan. 31, 2014	Apr. 30, 2013	Jan. 31, 2014	Jan. 31, 2014	Jan. 31, 2014	Jan. 31, 2014	Jan. 31, 2014	Jan. 31, 2014
In Thousands, unless otherwise specified			43.55.023(a)(1) [Member]	43.55.023(1)(1) [Member]	43.55.023(a)(2) [Member]	43.55.023(1)(2) [Member]	43.55.023(b) [Member]	43.55.025 [Member]
Alaska Production Tax Credits [Line Items]	'	'	'	'	'	'	'	'
Alaska capital expenditure credit (percent)	'	'	20.00%	40.00%	'	'	'	'
Alaska capital exploration credit (percent)	'	'	'	'	20.00%	40.00%	'	'
Alaska carried-forward annual loss credit (percent)	'	'	'	'	'	'	25.00%	'
Seismic exploration credits (percent)	'	'	'	'	'	'	'	40.00%
Expenditure and exploration credits	$43,218	$14,547	'	'	'	'	'	'
Alaska production tax credits receivable	$19,763	$12,713	'	'	'	'	'	'

Litigation_Details

Litigation (Details) (USD $)	0 Months Ended	9 Months Ended	0 Months Ended
In Thousands, unless otherwise specified	Jan. 24, 2014	Jan. 31, 2014	Feb. 07, 2014	Jan. 31, 2014	Jan. 31, 2014
			Subsequent Event [Member]	Voorhees [Member]	Cudd [Member]
Loss Contingencies [Line Items]	'	'	'	'	'
Litigation settlement	$1,250	'	'	'	'
Damages sought, minimum	'	3,000	'	'	'
Damages sought for loss of vested warrants	'	2,687	'	'	'
Estimated possible loss	'	'	'	531	1,889
Indemnity agreement amount	'	'	$500	'	'

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	Jan. 31, 2014	Mar. 11, 2011
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'	'
July 1, 2014 obligation	$1,500	'
July 1, 2015 obligation	2,000	'
July 1, 2016 obligation	2,500	'
July 1, 2017 obligation	2,000	'
July 1, 2018 obligation	1,500	'
July 1, 2019 obligation	1,500	'
Total obligations	$11,000	$12,000

Commitments_and_Contingencies_2

Commitments and Contingencies (Details Textual) (USD $)	9 Months Ended		0 Months Ended
	Jan. 31, 2014	Mar. 11, 2011	Nov. 05, 2009	Nov. 05, 2009
			WMRU [Member]	Redoubt Unit [Member]
Long-term Purchase Commitment [Line Items]	'	'	'	'
Notification deadline (in days)	'10 days	'	'	'
Project, item or purchase price	$5,000,000	'	'	'
Funding commitment	'	'	5,150,000	31,000,000
Bond amount	'	18,000,000	'	'
Funding obligations	11,000,000	12,000,000	'	'
Funded obligation	$1,000,000	'	'	'

Subsequent_Events_Details

Subsequent Events (Details) (Subsequent Event [Member])	Feb. 03, 2014
First Secured Promissory Note [Member]	'
Subsequent Event [Line Items]	'
Obligations of note payable repaid (percentage)	100.00%
Second Secured Promissory Note [Member]	'
Subsequent Event [Line Items]	'
Obligations of note payable repaid (percentage)	100.00%
Third Secured Promissory Note [Member]	'
Subsequent Event [Line Items]	'
Obligations of note payable repaid (percentage)	100.00%
Loan and Security Agreement [Member]	'
Subsequent Event [Line Items]	'
Obligations of note payable repaid (percentage)	100.00%

Subsequent_Events_Details_1

Subsequent Events (Details 1) (USD $)	0 Months Ended
	Nov. 22, 2013	Aug. 05, 2013	Apr. 25, 2013	Feb. 07, 2013	Jun. 29, 2012	Mar. 03, 2014	Feb. 03, 2014	Feb. 03, 2014
						Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]
							Installment	London Interbank Offered Rate (LIBOR) [Member]
Subsequent Event [Line Items]	'	'	'	'	'	'	'	'
Credit facility	'	'	'	'	$100,000,000	'	$175,000,000	'
Borrowing base	'	75,000,000	'	'	55,000,000	'	'	'
Increase in borrowing capacity	'	20,000,000	'	'	'	'	'	'
Prepayment fee	'	'	'	'	'	'	9,223,000	'
Number of prepayment fee installments	'	'	'	'	'	'	4	'
Amount payable per installment	'	'	'	'	'	'	2,306,000	'
Amount borrowed	'	20,000,000	10,000,000	5,000,000	40,000,000	'	175,000,000	'
Original issue discount (percent)	'	'	'	'	'	'	2.00%	'
Variable rate (percent)	'	'	'	'	'	'	'	9.75%
LIBOR floor rate (percent)	'	'	'	'	'	'	'	2.00%
Revolving credit facility amount	'	'	'	'	'	'	100,000,000	'
Maturity (in years)	'	'	'	'	'	'	'4 years	'
Maturity extension (in months)	'	'	'	'	'	'	'6 months	'
Repayments of credit facility	'	'	'	'	'	75,300,000	'	'
Acquisition cost	59,975,000	'	'	'	'	'	56,975,000	'
Repayment of notes payable obligation	'	'	'	'	'	'	$3,800,000	'

Subsequent_Events_Details_2

Subsequent Events (Details 2) (USD $)	0 Months Ended
In Thousands, unless otherwise specified	Nov. 22, 2013
	acre
	Well
Subsequent Event [Line Items]	'
Working interest acquired (percent)	100.00%
Number of gas wells	6
Area acquried (in acres)	15,465
Acquisition cost	$59,975
Series D Preferred Stock [Member]	'
Subsequent Event [Line Items]	'
Preferred stock issued for acquisition	$5,000

Subsequent_Events_Details_3

Subsequent Events (Details 3) (USD $)

9 Months Ended

0 Months Ended

9 Months Ended

16 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

9 Months Ended

0 Months Ended

1 Months Ended

0 Months Ended

In Thousands, except Share data, unless otherwise specified

Jan. 31, 2014

Jan. 31, 2013

Dec. 02, 2013

Sep. 03, 2013

Jun. 27, 2013

Jun. 03, 2013

7-May-13

Feb. 12, 2013

Sep. 28, 2012

Jan. 31, 2014

Jan. 31, 2014

Dec. 02, 2013

Sep. 30, 2013

Jan. 31, 2014

Jan. 31, 2014

Jan. 28, 2014

Sep. 03, 2013

Mar. 01, 2013

Jan. 31, 2014

Mar. 03, 2014

Mar. 03, 2014

Mar. 05, 2014

Mar. 03, 2014

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

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]

Cumulative Preferred Stock Subject to Mandatory Redemption [Member]

Cumulative Preferred Stock Subject to Mandatory Redemption [Member]

Cumulative Preferred Stock Subject to Mandatory Redemption [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Series B Preferred Stock [Member]

Series B Preferred Stock [Member]

Series B Preferred Stock [Member]

Series C Preferred Stock [Member]

Series D Preferred Stock [Member]

Series D Preferred Stock [Member]

Cumulative Preferred Stock Subject to Mandatory Redemption [Member]

Series B Preferred Stock [Member]

Subsequent Event [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Semiannual dividend paid (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$6.05

$5.16

'

'

'

'

$5.95

Cumulative dividend rate per annum (percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

12.00%

'

'

'

'

Liquidation preference (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$100

'

'

'

'

Dividend paid (in dollars per share)

'

'

$0.67

$0.67

'

$0.67

'

'

'

'

'

'

'

'

'

'

'

'

'

$0.67

'

'

'

Cumulative declared dividend rate per annum (percent)

'

'

'

'

'

'

'

'

'

10.75%

'

'

'

'

'

'

'

'

'

10.75%

'

'

'

Liquidation preference (in dollars per share)

'

'

'

'

'

'

'

'

'

$25

$25

'

'

'

'

'

'

'

'

$25

'

'

'

Dividend paid (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

$0.44

'

'

'

'

'

'

'

'

$0.66

'

'

Cumulative dividend rate per annum (percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10.50%

'

'

'

'

'

10.50%

'

'

Liquidation preference (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

$25

$25

'

'

'

'

'

$25

'

'

Shares issued (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000

1,069,301

1,069,301

69,031

'

'

'

'

'

1,417

'

Price per share (in dollars per share)

'

'

'

'

$21.50

'

$22.25

$22.90

$23

'

'

'

$25

'

'

'

'

'

'

'

'

$24

'

Gross proceeds

'

'

'

'

'

'

'

'

'

'

'

'

$25,000

$1,667

'

'

'

'

'

'

'

$34

'

Issuance costs

3,893

1,576

'

'

547

'

805

1,052

1,335

'

620

'

1,875

46

'

'

'

'

'

'

'

1

'

Net proceeds

'

'

'

'

'

'

'

'

'

'

'

'

$23,125

$1,621

'

'

'

'

'

'

'

$33

'

Subsequent_Events_Details_4

Subsequent Events (Details 4) (Chief Financial Officer [Member], USD $)	0 Months Ended
	Nov. 12, 2013	Nov. 12, 2013	Nov. 12, 2013	Nov. 12, 2013	Feb. 12, 2014	Feb. 12, 2014	Feb. 12, 2014
	Employee Stock Option [Member]	Employee Stock Option [Member]	Employee Stock Option [Member]	Employee Stock Option [Member]	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]
		May 12, 2014 Vesting [Member]	November 12, 2015 Vesting [Member]	November 12, 2016 Vesting [Member]		Restricted Stock [Member]	Employee Stock Option [Member]
Subsequent Event [Line Items]	'	'	'	'	'	'	'
Annual salary	'	'	'	'	$350,000	'	'
Restricted stock issued (in shares)	800,000	300,000	250,000	250,000	'	35,000	'
Exercise price (in dollars per share)	'	'	'	'	'	'	$6.11