Miller Energy Resources (MILL) 10-K 14 Jul 14 2014 Q4 Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Apr. 30, 2014	Jul. 07, 2014	Oct. 31, 2013
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-K	'	'
Document Period End Date	30-Apr-14	'	'
Document Fiscal Year Focus	'2014	'	'
Document Fiscal Period Focus	'Q4	'	'
Amendment Flag	'false	'	'
Entity Common Stock, Shares Outstanding	'	46,076,707	'
Entity Well-known Seasoned Issuer	'No	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Public Float	'	'	$189,925,560

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Apr. 30, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
CURRENT ASSETS:	'	'
Cash and cash equivalents	$5,749	$2,551
Restricted cash	679	7,531
Accounts receivable	6,409	3,204
Alaska production credits receivable, net	49,121	12,713
Inventory	5,102	3,382
Prepaid expenses and other	3,940	1,183
Assets held for sale	236	'
Total current assets	71,236	30,564
OIL AND GAS PROPERTIES, NET	644,827	491,314
EQUIPMENT, NET	35,369	37,571
OTHER ASSETS:	'	'
Land	1,848	542
Restricted cash, non-current	12,075	10,207
Deferred financing costs, net	803	2,085
Other assets	664	541
Total assets	766,822	572,824
CURRENT LIABILITIES:	'	'
Accounts payable	38,836	13,129
Accrued expenses	20,446	6,338
Short-term portion of derivative instruments	3,315	842
Deferred income taxes	2,858	'
Current portion of long-term debt	9,459	6,000
Total current liabilities	74,914	26,309
OTHER LIABILITIES:	'	'
Deferred income taxes	139,768	157,530
Asset retirement obligation	22,872	19,890
Long-term portion of derivative instruments	4,006	'
Long-term debt, less current portion	174,743	48,978
Total liabilities	416,303	252,707
COMMITMENTS AND CONTINGENCIES (Notes 4, 6 and 10)	'	'
MEZZANINE EQUITY:	'	'
Series C Cumulative Preferred Stock, redemption amount of $78,124 and $37,000, 3,250,000 shares authorized, 3,069,968 and 1,454,901 shares issued and outstanding as of April 30, 2014 and 2013, respectively	67,760	31,236
STOCKHOLDERS' EQUITY:	'	'
Series D Fixed Rate/Floating Rate Cumulative Redeemable Preferred Stock, redemption amount of $32,378 and $0, 4,000,000 shares authorized, 1,070,448 and 0 shares issued and outstanding as of April 30, 2014 and 2013, respectively	30,041	'
Series D Fixed Rate/Floating Rate Cumulative Redeemable Preferred Stock, held in escrow (Note 8)	-5,000	'
Common stock, $0.0001 par, 500,000,000 shares authorized, 45,756,697 and 43,444,694 shares issued and outstanding as of April 30, 2014 and 2013, respectively	4	4
Additional paid-in capital	98,788	88,184
Retained earnings	158,926	200,693
Total stockholders' equity	282,759	288,881
Total liabilities and stockholder's equity	$766,822	$572,824

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 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)	45,756,697	43,444,694	'	'	'
Shares outstanding (in shares)	45,756,697	43,444,694	'	'	'
Preferred Stock	'	'	'	'	'
Series C redemption amount	'	'	$78,124,000	$37,000,000	'
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	'	'	'	'	$32,378,000
Shares authorized (in shares)	'	'	'	'	4,000,000
Shares issued (in shares)	'	'	'	'	1,070,448
Shares outstanding (in shares)	'	'	'	'	1,070,448

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
REVENUES:	'	'	'
Oil sales	$64,500	$29,447	$31,880
Natural gas sales	4,969	468	613
Other	1,089	4,886	2,909
Total revenues	70,558	34,801	35,402
OPERATING EXPENSES:	'	'	'
Lease operating expense	20,187	22,288	11,305
Transportation costs	5,599	2,410	3,556
Cost of other revenue	1,147	4,189	926
General and administrative	31,744	26,067	29,718
Alaska carried-forward annual loss credits, net	-16,342	-3,268	'
Exploration expense	2,009	1,458	1,241
Depreciation, depletion and amortization	33,528	13,170	13,310
Accretion of asset retirement obligation	1,239	900	1,072
Other operating (income) expense, net	2,140	-64	-641
Total operating expenses	81,251	67,150	60,487
OPERATING LOSS	-10,693	-32,349	-25,085
OTHER INCOME (EXPENSE):	'	'	'
Interest expense, net	-7,470	-4,276	-1,837
Gain (loss) on derivatives, net	-10,179	6,751	-2,832
Other income (expense), net	34	-329	58
Loss on debt extinguishment	-15,145	'	'
Total other income (expense)	-32,760	2,146	-4,611
LOSS BEFORE INCOME TAXES	-43,453	-30,203	-29,696
Income tax benefit	-14,886	-9,783	-11,006
NET LOSS	-28,567	-20,420	-18,690
Accretion of Series A, C and D preferred stock	-2,721	-2,866	-847
Series C and D preferred stock accumulated dividends	-10,479	-2,209	'
NET LOSS ATTRIBUTABLE TO COMMON STOCKHOLDERS	($41,767)	($25,495)	($19,537)
LOSS PER COMMON SHARE:	'	'	'
Basic (in dollars per share)	($0.94)	($0.60)	($0.48)
Diluted (in dollars per share)	($0.94)	($0.60)	($0.48)
WEIGHTED AVERAGE NUMBER OF COMMON SHARES:	'	'	'
Basic (in shares)	44,445,556	42,682,685	40,811,308
Diluted (in shares)	44,445,556	42,682,685	40,811,308

Consolidated_Statement_of_Stoc

Consolidated Statement of Stockholders' Equity (USD $)

Total

Mezzanine Equity [Member]

Series C Preferred Stock [Member]

Series D Preferred Stock [Member]

Preferred Stock [Member]

Preferred Stock [Member]

Common Stock [Member]

Additional Paid-in Capital [Member]

Retained Earnings [Member]

Retained Earnings [Member]

Retained Earnings [Member]

Retained Earnings [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, 2011

$294,742

'

'

'

'

'

$4

$49,013

$245,725

'

'

'

Balance (in shares) at Apr. 30, 2011

'

'

'

'

'

'

39,880,251

'

'

'

'

'

Increase (Decrease) in Stockholders' Equity [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

Net loss

-18,690

'

'

'

'

'

'

'

-18,690

'

'

'

Accretion of preferred stock

'

-847

'

'

'

'

'

'

'

-847

'

'

Issuance of equity for services

1,501

'

'

'

'

'

'

1,501

'

'

'

'

Issuance of equity for services (in shares)

130,000

'

'

'

'

'

130,000

'

'

'

'

'

Issuance of equity for compensation

12,916

'

'

'

'

'

'

12,916

'

'

'

'

Issuance of equity for compensation (in shares)

'

'

'

'

'

'

107,500

'

'

'

'

'

Exercise of equity rights

1,383

'

'

'

'

'

'

1,383

'

'

'

'

Exercise of equity rights (in shares)

96,900

'

'

'

'

'

969,000

'

'

'

'

'

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

-20,420

'

'

'

'

'

'

'

-20,420

'

'

'

Accretion of preferred stock

'

'

-2,866

'

'

'

'

'

'

'

-2,866

'

Issuance of equity for services

2,154

'

'

'

'

'

'

2,154

'

'

'

'

Issuance of equity for services (in shares)

351,477

'

'

'

'

'

351,477

'

'

'

'

'

Issuance of equity for compensation

11,694

'

'

'

'

'

'

11,694

'

'

'

'

Issuance of equity for compensation (in shares)

'

'

'

'

'

'

527,665

'

'

'

'

'

Exercise of equity rights

3,832

'

'

'

'

'

'

3,832

'

'

'

'

Exercise of equity rights (in shares)

1,286,001

'

'

'

'

'

1,286,001

'

'

'

'

'

Series C preferred dividends

'

'

-2,209

'

'

'

'

'

'

'

-2,209

'

Other equity issuances

1,341

'

'

'

'

'

'

1,341

'

'

'

'

Other equity issuances (in shares)

192,800

'

'

'

'

'

192,800

'

'

'

'

'

Preferred stock redemption

2,510

'

'

'

'

'

'

2,510

'

'

'

'

Modification of warrants

1,840

'

'

'

'

'

'

1,840

'

'

'

'

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

-28,567

'

'

'

'

'

'

'

-28,567

'

'

'

Accretion of preferred stock

'

'

-2,459

'

'

'

'

'

'

'

-2,459

'

Issuance of equity for services

1,103

'

'

'

'

'

'

1,103

'

'

'

'

Issuance of equity for compensation

7,931

'

'

'

'

'

'

7,931

'

'

'

'

Issuance of equity for compensation (in shares)

'

'

'

'

'

'

630,349

'

'

'

'

'

Exercise of equity rights

4,638

'

'

'

'

'

'

4,638

'

'

'

'

Exercise of equity rights (in shares)

1,681,654

'

'

'

'

'

1,681,654

'

'

'

'

'

Series C preferred dividends

'

'

-8,349

'

'

'

'

'

'

'

-8,349

'

Other equity issuances

3

'

'

'

'

'

'

3

'

'

'

'

Issuance of Series D Preferred Stock

'

'

'

30,041

'

30,041

'

'

'

'

'

'

Issuance of Series D Preferred Stock (in shares)

'

'

'

'

'

1,284,034

'

'

'

'

'

'

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

'

'

'

-2,130

'

'

'

'

'

'

'

-2,130

Accretion of Series D Preferred Stock

'

'

'

-262

'

'

'

'

'

'

'

-262

Dissolution of MEI

-3,071

'

'

'

'

'

'

-3,071

'

'

'

'

Balance at Apr. 30, 2014

$282,759

'

'

'

$25,041

'

$4

$98,788

$158,926

'

'

'

Balance (in shares) at Apr. 30, 2014

'

'

'

'

1,070,448

'

45,756,697

'

'

'

'

'

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'	'
Net loss	($28,567)	($20,420)	($18,690)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:	'	'	'
Depreciation, depletion and amortization	33,528	13,170	13,310
Amortization of deferred financing fees	1,387	828	1,123
Expense from issuance of equity	9,034	10,722	14,072
Dry hole costs, leasehold impairments and non-cash exploration expenses	879	1,264	1,061
Payment-in-kind interest on debt	'	307	'
Non-cash loss on debt extinguishment	14,258	'	'
Deferred income taxes	-14,904	-9,789	-11,006
Derivative contracts:	'	'	'
(Gain) loss on derivatives, net	-10,179	6,751	-2,832
Cash settlements	-3,815	1,516	604
Alaska carried-forward annual loss credits, net	-16,342	-3,268	'
Accretion of asset retirement obligation	1,239	900	1,072
Other	958	'	'
Changes in operating assets and liabilities:	'	'	'
Receivables	2,848	-2	-808
Inventory	93	-1,676	-235
Prepaid expenses and other assets	-655	-829	-654
Accounts payable, accrued expenses, and other	5,202	2,537	4,220
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	15,322	-11,491	6,901
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'	'
Capital expenditures for oil and gas properties	-136,320	-26,492	-7,558
Proceeds from Alaska expenditure and exploration based credits	18,531	131	'
North Fork acquisition	-59,557	'	'
Prepayment of drilling costs	-1,692	'	'
Purchase of land	-356	'	'
Purchase of equipment and improvements	-2,943	-11,533	-26,409
Savant purchase deposit	-500	'	'
Proceeds from sale of equipment	'	2,000	'
NET CASH USED IN INVESTING ACTIVITIES	-182,837	-35,894	-33,967
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'	'
Cash dividends	-8,552	-1,231	'
Payments on debt	-75,306	-24,130	-8,764
Proceeds from borrowings	195,000	55,000	30,894
Debt acquisition costs	-5,827	-3,853	-2,140
Redemption of preferred stock	'	-11,240	'
Issuance of preferred stock	62,738	35,867	10,000
Repayment of MEI loans	-3,071	'	'
Equity issuance costs	-3,894	-2,667	'
Exercise of equity rights	4,638	3,832	1,383
Restricted cash	4,984	-5,613	-1,895
Other	3	'	'
NET CASH PROVIDED BY FINANCING ACTIVITIES	170,713	45,965	29,478
NET CHANGE IN CASH AND CASH EQUIVALENTS	3,198	-1,420	2,412
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	2,551	3,971	1,559
CASH AND CASH EQUIVALENTS AT END OF PERIOD	5,749	2,551	3,971
SUPPLEMENTARY CASH FLOW DATA:	'	'	'
Cash paid for interest	12,095	11,143	1,986
SIGNIFICANT NON-CASH INVESTING AND FINANCING ACTIVITIES:	'	'	'
Capital expenditures in accounts payable and accrued expenses	28,656	3,154	954
Reduction of oil and gas properties and equipment from applications for Alaska expenditure and exploration based credits	41,841	6,713	4,250
Issuance of Series D Preferred Stock held in escrow	5,000	'	'
Accretion of preferred stock	$2,721	$2,866	$847

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Apr. 30, 2014
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	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 eastern 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.
	Principles of Consolidation
	The accompanying consolidated financial statements include the accounts of Miller Energy Resources, Inc. and our wholly owned subsidiaries (collectively, the "Company"). The 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. All intercompany balances and transactions are eliminated in the consolidation.
	Reclassifications
	Certain amounts in prior fiscal years have been reclassified to conform with the presentation adopted in the current fiscal year.
	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 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
	Risks and Uncertainties
	Factors that could affect our future operating results and cause actual results to vary materially from management's expectation include, but are not limited to: the capital intensive nature of our business and our ability to maintain and secure adequate capital to fully develop our operations and assets; our ability to perform under the terms of the Alaska Oversight Agreement with the Alaska DNR, including meeting the funding requirements of that agreement; the imprecise nature of our reserve estimates; our ability to recover proved undeveloped reserves and convert probable and possible reserves to proved reserves; fluctuating oil and natural gas prices; changes in environmental or regulatory requirements; our ability to control expenses; our ability to comply with covenants related to our credit facilities; and the impact of changes in accounting principles. Negative developments in these or other risk factors could have a significant adverse effect on our financial position, results of operations and cash flows.
	Use of Estimates
	The preparation of consolidated financial statements in conformity with GAAP requires us to make a number of estimates and assumptions relating to the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. We base our estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about carrying values of assets and liabilities that are not readily apparent from other sources. We evaluate our estimates and assumptions on a regular basis. Actual results may differ from these estimates and assumptions used in preparation of its financial statements and changes in these estimates are recorded when known. Significant estimates made in preparing these financial statements include the fair value determination of acquired assets and liabilities assumed, the estimate of proved oil and gas reserves and related present value estimates of future net cash flows therefrom (see Supplemental Oil and Gas Disclosures (Unaudited)), assessing asset retirement obligations (see Note 5 - Asset Retirement Obligations) and the estimate of income taxes (see Note 7 - Income Taxes).
	Cash Equivalents
	We consider all highly liquid short-term investments with a maturity of three months or less at the time of purchase to be cash equivalents. These investments are carried at cost, which approximates fair value due to their short-term nature.
	Restricted Cash
	As of April 30, 2014 and 2013, current restricted cash includes $38 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. Non-current restricted cash balances include amounts held in escrow to provide for the future plugging and abandonment of wells, dismantling of our off-shore platform, and general liability bonds.
	Accounts Receivable and Allowance for Doubtful Accounts
	Accounts receivable are stated at the historical carrying amount net of write-offs and allowance for uncollectible accounts. We routinely assess the recoverability of all material customer and other receivables to determine their collectability and record a reserve when, based on the judgment of management, it is probable that a receivable will not be collected and the amount of the reserve may be reasonably estimated. When collection is no longer pursued, we charge uncollectible accounts receivable against the reserve. As of April 30, 2014 and 2013, we established a reserve of $250 and $0, respectively.
	Inventory
	Inventory consists of crude oil produced but not sold, stated at the lower of cost or market.
	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 depreciated using the unit-of-production method based on estimated total 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 estimated total proved reserves.
	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 established 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. In fiscal 2014, our consolidated statement of operations includes $296 in abandoned leases, $1,695 in seismic and delay rentals incurred in the Cook Inlet region, and $19 related to delay rentals incurred in the Appalachian region.
	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.
	Capitalized Interest
	Interest is capitalized as part of the historical cost of developing and constructing assets for significant projects. Significant investments in unproved oil and gas properties, significant exploration and development projects for which depreciation, depletion and amortization ("DD&A") is not currently recognized, and exploration or development activities that are in progress qualify for interest capitalization. Interest is capitalized until the asset is ready for service. Capitalized interest is determined based upon our weighted-average borrowing cost on debt for the average amount of qualifying costs incurred. The Company incurred $14,433, $9,289 and $5,500 of interest expense and amortization of deferred financing costs in fiscal years 2014, 2013 and 2012, respectively, of which $8,569, $5,880 and $3,700, respectively, were capitalized in equipment and oil and gas properties on the balance sheet. Once an asset subject to interest capitalization is completed and placed in service, the associated capitalized interest is expensed through DD&A or impairment, along with other capitalized costs related to that asset.
	Asset Retirement Obligations
	Asset retirement obligations ("ARO") reflects the estimated present value of the amount of dismantlement, removal, site reclamation, and similar activities associated with our oil and gas properties. We utilize current retirement costs to estimate the expected cash outflows for retirement obligations. We estimate 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.
	The initial estimated ARO is recorded as a liability, with an offsetting asset retirement cost recorded as an increase to the associated property and equipment on the consolidated balance sheet. If the fair value of the recorded ARO changes, a revision is recorded to both the asset retirement obligation and the asset retirement cost. Revisions in estimated liabilities can result from changes in estimated inflation rates, changes in service and equipment costs and changes in the estimated timing of an asset’s retirement. Asset retirement costs are depreciated using a systematic and rational method similar to that used for the associated property and equipment. Accretion expense on the liability is recognized over the estimated productive life of the related assets.
	Loss Contingencies
	Accruals for loss contingencies arising from claims, assessments, litigation, environmental and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. These accruals are adjusted as additional information becomes available or circumstances change.
	Revenue Recognition
	Oil and natural gas sales revenues are recognized when production is sold to a purchaser at a fixed or determinable price, when delivery has occurred and title has transferred, and if collectability of the revenue is reasonably assured. Cash received relating to future revenues is deferred and recognized when all revenue recognition criteria are met.
	Derivative Instruments
	We utilize derivatives to manage our commodity price risk.
	We account for our derivative instruments in accordance with ASC 815, “Derivatives and Hedging,” which requires that all derivative instruments, other than those that meet the normal purchases and sales exception, be recorded on the consolidated balance sheets at fair value as either a current or non-current asset or liability, depending on the derivative position and the expected timing of settlement. We report these amounts on a gross basis. The Company’s derivative instruments were not designated as hedges for accounting purposes for any of the periods presented. Accordingly, the changes in fair value are recognized in the consolidated statements of operations in the period of change. Gains and losses on derivatives are included in cash flows from operating activities.
	Fair Value Measurements
	We measure fair value of our financial and non-financial assets and liabilities on a recurring basis. Accounting standards define fair value, establish a framework for measuring fair value and require certain disclosures about fair value measurements for assets and liabilities measured on a recurring basis. All of our derivative instruments are recorded at fair value in our financial statements. Fair value is the exit price that we would receive to sell an asset or pay to transfer a liability in an orderly transaction between market participants at the measurement date.
	The following hierarchy prioritizes the inputs used to measure fair value:
	•	Level 1 - Measurements are based on quoted prices in active markets that are unadjusted and accessible at the measurement date for identical, unrestricted assets or liabilities;
	•	Level 2 - Measurements are based on significant observable pricing inputs other than quoted prices included in Level 1 that are either directly or indirectly observable as of measurement date; or
	•	Level 3 - Measurements are based on process or valuation models that use inputs that are both significant to the fair value measurement and less observable from objective sources (i.e., supported by little or no market activity). These inputs generally reflect management’s own assumptions about the assumptions a market participant would use in pricing the asset or liability.
	Valuation techniques that maximize the use of observable inputs are favored. Assets and liabilities are classified in their entirety based on the lowest priority level of input that is significant to the fair value measurement. The assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the placement of assets and liabilities within the levels of the fair value hierarchy. 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.
	Stock-Based Compensation
	We grant various types of stock-based awards including stock options, restricted stock units, and performance-based awards. Stock-based compensation awards granted are valued on the date of grant and are expensed, net of estimated forfeitures, over the requisite service period.
	Income Taxes
	Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date or the date of change in estimate for income taxes.
	We routinely assess the realizability of our deferred tax assets. If we conclude that it is more likely than not that some or all of the deferred tax assets will not be realized, the tax asset is reduced by a valuation allowance. Numerous judgments and assumptions are inherent in the determination of future taxable income, including factors such as future operating conditions (particularly as related to prevailing oil and gas prices) and changing tax laws.
	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 consolidated balance sheets.
	Guarantees
	On July 12, 2012, we signed a direct guarantee for 55% of the loan obligations outstanding of $5,074 with FSG Bank for the Pellissippi Pointe equity investment. The Company's guarantee is included within the scope of ASC 460, "Guarantees" and a liability was recorded at the estimated fair value of $250; such amount is included in accrued expenses on our consolidated balance sheet as of April 30, 2013 and April 30, 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 April 30, 2014, our maximum potential undiscounted payment under this arrangement is $2,791 plus additional lender's costs.
Income (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).
Business Combinations
We account for business combinations under the acquisition method of accounting. The acquisition method requires that the acquired assets and liabilities, including contingencies, be recorded at fair value determined on the acquisition date and that changes thereafter be reflected in income (loss). The estimation of the fair values of the assets acquired and liabilities assumed involves a number of estimates and assumptions that could differ materially from the actual amounts recorded. The results of the acquired businesses are included in our results from operations beginning from the day of acquisition.
Statement of Comprehensive Income
No statement of comprehensive income is presented since net income (loss) and comprehensive income (loss) would be the same for all periods reported.
New Accounting Pronouncements Issued But Not Yet Adopted
In July 2013, the FASB issued ASU 2013-11, "Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists." The amendments in ASU 2013-11 require an entity to present an unrecognized tax benefit in the financial statements as a reduction to a deferred tax asset for a net operating loss ("NOL") carryforward, a similar tax loss, or a tax credit carryforward except when: (1) a NOL carryforward, a similar tax loss, or a tax credit carryforward is not available as of the reporting date under the governing tax law to settle taxes that would result from the disallowance of the tax position; or (2) the entity does not intend to use the deferred tax asset for this purpose (provided that the tax law permits a choice). If either of these conditions exists, an entity should present an unrecognized tax benefit in the financial statements as a liability and should not net the unrecognized tax benefit with a deferred tax asset. The amendment does not affect the recognition or measurement of uncertain tax positions under ASC Topic 740, "Income Taxes". The amendments in this ASU are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. The amendments should be applied prospectively to all unrecognized tax benefits that exist at the effective date. Retrospective application is permitted. We do not expect this ASU to have a material impact to our consolidated financial statements.
In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606)” (“ASU 2014-09”). ASU 2014-09 is intended to improve the financial reporting requirements for revenue from contracts with customers by providing a principle based approach. The core principal of the standard is that revenue should be recognized when the transfer of promised goods or services is made in an amount that the entity expects to be entitled to in exchange for the transfer of goods and services. ASU 2014-09 also requires disclosures enabling users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. This standard will be effective for financial statements issued by public companies for annual reporting periods beginning after December 15, 2016. Early adoption is not permitted. The Company is currently evaluating the potential impact of ASU 2014-09 on the 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.

Derivative_Instruments

Derivative Instruments	12 Months Ended
	Apr. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments	'
	DERIVATIVE INSTRUMENTS
	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 derivatives for crude oil on a portion of our crude oil production. We utilize over-the-counter variable-to-fixed price swap contracts to manage fluctuations in cash flows resulting from changes in commodity prices.
	As of April 30, 2014, we had the following open crude oil derivative positions. All are priced based on the ICE Brent crude oil futures as traded on the New York Mercantile Exchange.
			Fixed - Price Swaps
	Production Period ending April 30,		Bbls			Weighted Average Fixed Price
	2015		785,000			$	100.75
	2016		787,600			$	95.66
	2017		232,600			$	94.27
	Derivative Activities Reflected on Consolidated Balance Sheets
	The following table presents the fair value of commodity derivatives. The fair value amounts are presented on a gross basis and do not reflect the netting of asset and liability positions permitted under the terms of our master netting arrangements.
			Asset Derivatives										Liability Derivatives
			April 30, 2014						April 30, 2013				April 30, 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		$	88			Prepaid expenses and other		$	—	Current portion of derivative instruments	$	(3,315	)	Current portion of derivative instruments	$	(842	)
	Commodity derivatives		Other assets		26				Other assets		—		Long-term portion of derivative instruments	(4,006		)	Long-term portion of derivative instruments	—
	Total derivatives not designated as hedging instruments under ASC 815				$	114					$	—		$	(7,321	)		$	(842	)
	Offsetting of Derivative Assets and Liabilities
	The following table presents our gross and net derivative assets and liabilities:
		Gross Amount Presented on Balance Sheet				Netting Adjustments (a)				Net Amount
	April 30, 2014
	Derivative assets with right of offset or master netting agreements	$	114			$	(114	)		$	—
	Derivative liabilities with right of offset or master netting agreements	$	(7,321	)		$	114			$	(7,207	)
	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 Consolidated Statements of Operations
	Gains and losses on derivatives are reported in the consolidated statements of operations. The following represents the Company’s reported gains and losses on derivative instruments for the years presented:
		For the Year Ended April 30,
		2014				2013				2012
	Gain (loss) on derivatives, net	$	(10,179	)		$	6,751			$	(2,832	)
	Credit Risk Related Contingent Features in Derivatives
	None of the Company’s derivative instruments contains credit-risk related contingent features. No collateral was posted by the Company related to net positions as of April 30, 2014 and 2013.
	Warrant Derivatives
	Series A Cumulative Preferred Stock. In April 2012, purchasers of our Series A Cumulative Preferred Stock (the "Series A Preferred Stock") were issued warrants to purchase an aggregate amount of 1,000,000 shares of our common stock at an exercise price of $5.28 per share. These warrants were subject to a reset provision requiring adjustment of the exercise price, from $5.28 to $3.00, if the preferred stock was not redeemed within 30 days of our refinancing and repayment of the Guggenheim Credit Facility.
	The Series A Preferred Stock was redeemed on June 29, 2012 in connection with the initiation of the Prior Credit Facility and the repayment of the Guggenheim Credit Facility. The mark-to-market adjustment from May 1, 2012 to June 29, 2012 of $443 was recorded to gain on derivatives, net, and the remaining liability of $2,510 was reclassified to additional paid-in capital.
	Warrants Issued in Connection with Other Equity Transactions
	From time to time we issue warrants to third parties in exchange for services. Certain warrants that we issued contained exercise reset provisions, which were considered freestanding derivatives, and were accounted for as liabilities measured at fair value in accordance with ASC 815, “Derivatives and Hedging.”
	On March 26, 2010, purchasers of our common stock and certain third party consultants were issued warrants to purchase an aggregate amount of 817,055 shares of our common stock at an exercise price of $5.28 per share. Under the terms of the respective agreements, an adjustment to the exercise price was required if, at any time after issuance, we issue warrants at an exercise price lower than $5.28.
	On September 21, 2012, the Company entered into a Special Warrant Exercise Agreement with warrant holders, pursuant to which, warrant holders agreed to exercise 586,001 warrants immediately for $4.00 per share and waived their right to a cashless exercise.  In addition, 42,857 warrants were cancelled in exchange for a settlement payment of $75.  These modifications resulted in a loss of $210, which is included in other income (expense), net on our consolidated statement of operations for the year ended April 30, 2013.
	The term for the remaining 138,197 warrants outstanding was extended for one year in exchange for the removal of the exercise price reset provision.  The mark-to-market adjustment from May 1, 2012 to September 21, 2012 of $260 was recorded to gain (loss) on derivatives, net, and the remaining liability of $1,840 was reclassified to additional paid-in capital.

Acquisitions_Acquisitions

Acquisitions Acquisitions	12 Months Ended
	Apr. 30, 2014
Business Combinations [Abstract]	'
Acquisitions	'
	ACQUISITIONS
	On November 22, 2013, the Company entered into a purchase and sale agreement by and among Armstrong Cook Inlet, LLC, GMT Exploration Company, LLC, Dale Resources Alaska, LLC, Jonah Gas Company, LLC and Nerd Gas Company, LLC and the Company. Pursuant to the North Fork Purchase Agreement, the Company (i) acquired 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 for cash consideration of $59,557 and (ii) all the issued and outstanding membership interests of Anchor Point Energy, LLC, a limited liability company owning certain pipeline facilities and related assets which service the North Fork Properties, for 213,586 shares (valued at approximately $5,000) of the Company's Series D Preferred Stock. The Company used $56,577 of funds under the Second Lien Credit Facility to finance the acquisition and paid $3,000 in cash as a deposit on November 22, 2013 that was applied toward the purchase price.
	The acquisition of the North Fork Properties closed on February 4, 2014 and the acquisition of the Anchor Point Equity will close upon receiving approval from the Regulatory Commission of Alaska, which has not occurred as of April 30, 2014. The consideration consisting of the Company’s Series D Preferred Stock for Anchor Point Equity was deposited into an escrow account and will be disbursed to the North Fork Sellers upon the closing of the Anchor Point Equity acquisition pursuant to the terms of the North Fork Purchase Agreement.
	The purchase of the North Fork Properties has been accounted for under ASC 805, "Business Combinations." Under ASC 805, the Company is required to allocate the purchase price to assets acquired and liabilities assumed based on their fair values at the acquisition date. The estimated fair value of the properties approximates the fair value of consideration, and as a result, no goodwill was recognized. The following table summarizes the consideration paid for the North Fork Properties and the preliminary allocation of the purchase price to the assets acquired and liabilities assumed that have been included in the Company's consolidated financial statements for periods subsequent to the acquisition date.
	Accounts receivable	$	49
	Proved oil and gas properties	55,454
	Unproved oil and gas properties	5,958
	Accounts payable	(433		)
	Asset retirement obligation	(1,437		)
	Long-term liabilities	(34		)
	Consideration paid	$	59,557
	Acquisition-related costs of $404 were expensed by the Company and are included in general and administrative expenses in the consolidated statement of operations. Net revenue of $4,124 is included in the consolidated statements of operation for the year ended April 30, 2014 related to the North Fork Properties. Pro forma presentation of revenue and earnings for the years ended April 30, 2014 and April 30, 2013, as required by ASC 805 is impractical due to the present inaccessibility of sufficient financial records to produce relevant and reliable financial information.

Debt

Debt	12 Months Ended
	Apr. 30, 2014
Debt Disclosure [Abstract]	'
Debt	'
	DEBT
	As of April 30, 2014 and 2013, we had the following debt obligations reflected at their respective carrying values on our consolidated balance sheets:
		As of April 30,
		2014			2013
	Second Lien Credit Facility	$	175,000		$	—
	Debt discount related to Second Lien Credit Facility	(3,296		)	—
	Gunsight Promissory Note payable	950			—
	Apollo prepayment and extension fee note payable	9,223			—
	Apollo senior secured Credit Facility	—			55,307
	Debt discount related to Apollo senior secured Credit Facility	—			(2,581		)
	Series B Preferred Stock	2,325			2,252
	Total debt obligations	184,202			54,978
	Less: Current maturities	(9,459		)	(6,000		)
	Total debt less current maturities	$	174,743		$	48,978
	Second Lien Credit Facility
	On February 3, 2014, we refinanced the Prior Credit Facility by entering into the New Apollo Loan Agreement which set forth the terms of the Second Lien Credit Facility.
	The New Apollo Loan Agreement provides for a $175,000 term credit facility, all of which was made available to and drawn by us on the closing date. The amounts drawn were subject to a 2% original issue discount. Amounts outstanding under the Second Lien Credit Facility bear interest at a rate of LIBOR plus 9.75%, subject to a 2% LIBOR floor. The Second Lien Credit Facility permitted us to enter into the First Lien RBL discussed below in Note 16 - Subsequent Events. Upon entering into such revolving credit facility and a related intercreditor agreement, and subject to the terms of those agreements, the Second Lien Credit Facility became a second-lien credit facility subordinated to the First Lien RBL. We entered into the First Lien RBL on June 2, 2014, and amended the New Apollo Loan Agreement. The Second Lien Credit Facility carries a four year maturity. The Second Lien Credit Facility contains a leverage ratio, interest coverage ratio, current ratio, asset coverage ratio, minimum gross production and change of management control covenants, as well as other covenants customary for a transaction of this type. As we entered into an amendment to the New Apollo Loan Agreement in connection with the First Lien RBL, we did not calculate whether we were in compliance with the required financial and production covenants as of April 30, 2014 as such compliance (or non-compliance) was no longer relevant. Subject to certain conditions contained in the New Apollo Loan Agreement, the Second Lien Credit Facility also allows for us to implement a discretionary share repurchase plan on terms and conditions reasonably satisfactory to Apollo (as "administrative agent") and the lenders.
	We used $75,306 of the proceeds drawn under the Second Lien Credit Facility to refinance the Prior Credit Facility with Apollo and $56,577 to finance the acquisition of the North Fork Unit. In addition, $3,071 was used to retire the obligations owed under the MEI Loan Documents (as defined below). The remainder of the proceeds from the Second Lien Credit Facility will be used for general corporate purposes. The fair value of the outstanding balance of the New Credit Facility was $176,785 as of April 30, 2014, as calculated using the discounted cash flows method.
	On the closing date, in connection with the Second Lien Credit Facility, we, along with all of our consolidated subsidiaries (other than MEI), entered into an Amended and Restated Guarantee and Collateral Agreement (the "Second Lien Guarantee") with Apollo, for the benefit of the lenders from time to time party to the New Loan Agreement. Under the terms of the Second Lien Guarantee and related security documents each of our consolidated subsidiaries (other than MEI) have guaranteed our obligations under the Second Lien Credit Facility and we and those subsidiaries have granted a security interest in substantially all of their assets to secure the performance of the obligations arising under the Second Lien Credit Facility.
	Subsequent to quarter end, we entered into the First Lien RBL, and made certain amendments to the New Apollo Loan Agreement to conform certain provisions to the First Lien Loan Agreement. See Note 16 - Subsequent Events below for more detail.
	Apollo Senior Secured Credit Facility ("Prior Credit Facility")
	On June 29, 2012, we entered into a Loan Agreement (the "Prior Loan Agreement") with Apollo, as administrative agent and sole initial lender. The Prior Loan Agreement provided for a $100,000 credit facility with an initial borrowing base of $55,000 (the "Original Availability"). Of that initial $55,000, $40,000 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 Miller 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 above, on February 3, 2014, we refinanced the Prior Credit Facility by entering into the New Apollo Loan Agreement among us, as borrower, Apollo, as administrative agent, and the lenders from time to time party thereto, which amended and replaced the terms of the Prior Credit Facility with the terms of the Second Lien 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 guarantee 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 could 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 included 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 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. On December 9, 2013, we received an amendment and waiver from Apollo 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 by entering into the New Apollo Loan Agreement on February 3, 2014, we did not calculate whether we were in compliance with the required financial and production covenants as of April 30, 2014 as such compliance (or non-compliance) was no longer relevant.
	On the closing date of the Prior Loan Agreement, we paid Apollo a non-refundable structuring fee of $2,750, payable to the account of the lenders, and we 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 the first anniversary of the closing date.
	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 would have been 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 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 amounts outstanding under the Prior Credit Facility is made from the proceeds of tax credits received by us under Alaska's Clear and Equitable Share program, that pre-payment will be applied pro rata to both the Additional Availability and previously drawn amounts.
	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, applies to the amounts drawn prior to the Sixth Amendment 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 amounts owed under the Prior Credit Facility.
	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 10 - Litigation).
	As noted above, on February 3, 2014, we refinanced the Prior Credit Facility by entering into the New Apollo Loan Agreement among us, Apollo as the administrative agent, and the lenders party thereto from time to time. The New Apollo 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. The New Apollo Loan Agreement is discussed above under "Second Lien Credit Facility."
	Series B Preferred Stock
	On September 24, 2012, we sold 25,750 shares of our 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 April 30, 2014, the fair value of Series B Preferred Stock was $2,197, 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, beginning 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 the payment of a semiannual dividend, of approximately $5.95 per share, which 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.
	Repayment of MEI Loans
	On February 3, 2014, we repaid all obligations under the MEI Loan Documents between MEI and us. The MEI Loan Documents have terminated.
	Promissory Note to Gunsight Holdings, LLC
	On February 27, 2014, in connection with our acquisition of certain acreage in Tennessee, we signed a promissory note in the amount of $950 payable to the seller, Gunsight Holdings, LLC (the “Gunsight Note”).  Interest accrues at a rate of 5% per annum.  The Gunsight Note provides for quarterly interest payments and a balloon payment of the principal amount is due on February 27, 2017, and may be prepaid without penalty.  The Gunsight Note is secured by a purchase money deed of trust on the property acquired dated February 27, 2014.
	Debt Issuance Costs
	As of April 30, 2014 and April 30, 2013, our unamortized deferred financing costs were $803 and $2,085, respectively, which relates to the Second Lien Credit Facility, Prior Credit Facility, and the Series B Preferred Stock. As of April 30, 2014 and April 30, 2013, our unamortized debt discount, which relates to the Second Lien Credit Facility and Prior Credit Facility, was $3,296 and $2,581, respectively. These costs are being amortized over the term of the respective debt instruments.
	Debt Extinguishment Costs
	In connection with the termination and repayment of the loans outstanding under the Prior Credit Facility, the Company determined that the Second Lien Credit Facility had substantially different terms from the Prior Credit Facility and recorded a loss on debt extinguishment of $15,145, consisting of a $9,223 prepayment and extension fee owed to Apollo payable in four equal installments of $2,306 on the last day of each calendar quarter, commencing June 30, 2014, and a charge of $5,185 to extinguish the debt discount, the unamortized deferred financing costs and prepaid administrative fee. Additionally, there was a charge of $737 in connection with the termination and repayment of all obligations under the MEI Loan Documents.

Asset_Retirement_Obligations

Asset Retirement Obligations	12 Months Ended
	Apr. 30, 2014
Asset Retirement Obligation Disclosure [Abstract]	'
Asset Retirement Obligations	'
	ASSET RETIREMENT OBLIGATIONS
	The following table presents changes to the Company's asset retirement obligation liability for the years ended April 30, 2014 and 2013:
		2014			2013
	Asset retirement obligation, beginning of year	$	19,890		$	18,366
	Additions	1,744			64
	Accretion expense	1,239			900
	Settlements	(36		)	—
	Revisions	35			560
	Asset retirement obligation, end of year	$	22,872		$	19,890
	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. There were no significant expenditures for abandonments during the years ended April 30, 2014, 2013 or 2012.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Apr. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	COMMITMENTS AND CONTINGENCIES
	On November 5, 2009, CIE entered into the Alaska Oversight Agreement ("AOA") with the 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. 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 quarterly 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 April 30, 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

Income_Taxes

Income Taxes	12 Months Ended
	Apr. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	INCOME TAXES
	The components of income tax benefit are as follows:
		For the Year Ended April 30,
		2014				2013				2012
	Federal:
	Current	$	—			$	—			$	—
	Deferred	(14,132		)		(10,023		)		(10,168		)
	Total	(14,132		)		(10,023		)		(10,168		)
	State:
	Current	18				6				—
	Deferred	(772		)		234				(838		)
	Total	(754		)		240				(838		)
	Total income tax benefit	$	(14,886	)		$	(9,783	)		$	(11,006	)
	A reconciliation of the provision for income taxes as reported and the amount computed by multiplying income before taxes by the U.S. federal statutory rate of 35% is as follows:
		For the Year Ended April 30,
		2014			2013			2012
	Provision calculated at federal statutory rate	(35.0	)%		(35.0	)%		(35.0	)%
	State and local income taxes, net of federal benefit	(8.4	)		(8.4	)		(7.8	)
	Change in effective state tax rate	(1.5	)		9.3			5
	State valuation allowance	8.1			—			—
	Other	2.5			1.7			0.7
	Total income tax benefit	(34.3	)%		(32.4	)%		(37.1	)%
	Significant components of the Company's deferred tax assets (liabilities) consist of the following:
		April 30,
		2014				2013
	Deferred tax assets:
	Unrealized derivative loss	$	2,995			$	397
	Apollo prepayment penalty	3,832				—
	Net operating loss carryforwards	36,542				31,136
	Stock options and warrants	12,865				11,384
	Other	3,055				2,126
	Total deferred tax assets	59,289				45,043
	Valuation allowance	(3,527		)		—
	Total deferred tax assets, net of valuation allowance	55,762				45,043
	Deferred tax liabilities:
	Excess of book basis over tax basis of oil and gas properties and equipment	(191,389		)		(200,912		)
	Alaska carried-forward annual loss credits	(6,845		)		(1,401		)
	Other	(154		)		(260		)
	Total deferred tax liabilities	(198,388		)		(202,573		)
	Net deferred tax liability	$	(142,626	)		$	(157,530	)
	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 have taken 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. Partly as a result of these elections, we presently have U.S. federal and state net operating loss carryovers that are expected to be 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. At April 30, 2014, we had net operating loss carryforwards for federal income tax purposes of approximately $81,737 with expiration beginning 2028.
	In assessing the realizable value of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which these temporary differences become deductible. Management believes, based on the assessment of both positive and negative evidence and objective and subjective evidence, that it is more likely than not that all of the deferred tax assets will be realized with the exception of certain state net operating losses and credits. At April 30, 2014, we determined that our Tennessee net operating loss carryforwards and credits may not be fully utilized; as such, we recorded a full valuation allowance of $3,527 against them.
	In our assessment that no valuation allowance is needed against our remaining deferred tax assets, we are relying solely on the reversal of significant existing temporary differences related to the excess of the Company's book carrying value of its oil and gas properties over their collective tax bases to support the recovery of our deferred tax assets (primarily net operating loss carryovers). Additionally, we experienced a "section 382 ownership change" in our fiscal year ended April 30, 2010. However, we do not expect that this event will result in loss of availability of any tax attribute (such as our net operating loss carryover). No valuation allowance was maintained against deferred tax assets at April 30, 2013.
	Pursuant to ASC 718-740-25-10, we have not recorded the tax benefit and related deferred tax asset for the windfall portion of stock compensation tax deductions that either create a net operating loss carry-forward or increase a net operating loss carry-forward. As such, the amount of net operating loss carry-forwards for which a tax benefit would be recorded to additional paid-in capital when the tax benefit is realized is approximately $175 as of April 30, 2014.
	We conduct business solely in the United States and, as a result, file income tax returns in the U.S. federal jurisdiction and in Alaska and Tennessee. The taxable years ended April 30, 2014, 2013, 2012 and 2011 remain open to examination by the taxing jurisdictions to which we are subject. Additional years may be subject to examination to the extent that our net operating loss carry-forwards are utilized in an open tax year. Generally, for tax years which produce net operating losses, capital losses or tax credit carry-forwards ("tax attributes"), the statute of limitations does not close, to the extent of these tax attributes, until the expiration of the statute of limitations for the tax year in which they are fully utilized. The Company and its consolidated subsidiaries are currently undergoing a U.S. federal income tax examination for the tax year ended April 30, 2012. The State of Alaska's Department of Revenue is also examining income tax returns of the Company and its Cook Inlet subsidiary (CIE) for the tax years 2010 through 2012. No significant cash tax payments or adjustments to tax attribute carryforwards are expected to result from the examinations at this time. No other state income tax examinations are currently ongoing.
	We have not identified any uncertain tax positions. No significant payments are expected during the succeeding 12 months.

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Apr. 30, 2014
Stockholders' Equity Note [Abstract]	'
Stockholders' Equity	'
	STOCKHOLDERS' EQUITY
	Common Stock
	At April 30, 2014, we had 45,756,697 shares of common stock outstanding. We issued 2,312,003 shares during the year ended April 30, 2014, of which 630,349 shares were issued to employees for compensation and 1,681,654 shares were related to the exercise of equity rights.
	At April 30, 2013, we had 43,444,694 shares of common stock outstanding. We issued 2,357,943 shares during the year ended April 30, 2013, of which 351,477 shares were issued for services, 527,665 shares were issued to employees for compensation, and 1,286,001 shares were related to the exercise of equity rights, and 192,800 shares for other equity issuances.
	At April 30, 2012, we had 41,086,751 shares of common stock outstanding. We issued 1,356,500 shares during the year ended April 30, 2012, of which 130,000 shares were issued for services and equipment, 257,500 shares were issued to employees for compensation, and 96,900 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 Series C Preferred Stock pursuant to the Company's shelf registration statement on Form S-3, which became effective on September 28, 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 the Series C ATM Agreement with 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 April 30, 2014, we sold 924,968 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 $20,935 and incurred issuance costs of $733, yielding net proceeds of $20,202.
	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 $2,459 during the year ended April 30, 2014. The fair value of the Series C Preferred Stock was $77,976 as of April 30, 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 Redeemable Preferred Stock, which is senior to the Series C Preferred Stock;
	•	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, as required in accordance with our charter, 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.
	On April 16, 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 June 2, 2014, in accordance with the terms of our charter, as June 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 March 2014 through May 2014. The record date, as required in accordance with our charter, was May 15, 2014.
	Series D Preferred Stock
	On September 30, 2013, we sold 1,000,000 shares of the Company’s newly designated 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 the Series D ATM Agreement with MLV. The Series D ATM Agreement contemplates periodic sales by MLV of our Series D Preferred 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 April 30, 2014, we sold 70,448 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 $1,701 and incurred issuance costs of $47, yielding net proceeds of $1,654 in connection with these sales.
	On January 31, 2014, pursuant to our Purchase and Sale Agreement with by and among Armstrong Cook Inlet, LLC, GMT Exploration Company, LLC, Dale Resources Alaska, LLC, Jonah Gas Company, LLC and Nerd Gas Company, LLC, we issued 213,586 shares of our Series D Preferred Stock to be held in escrow for the benefit of the North Fork 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. Pursuant to the Purchase and Sale Agreement, we are required to pay dividends on the Series D Preferred Stock held in escrow that are declared after January 31, 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 $262 during the year ended April 30, 2014. The fair value of the Series D Preferred Stock was $31,330 as of April 30, 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 from 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 from 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 December 2013 through February 2014. The record date was February 17, 2014.
	On April 16, 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 June 2, 2014, in accordance with the terms of our charter, as June 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 March 2014 through May 2014. The record date was May 15, 2014.
	Issuance of Common Stock
	On September 18, 2013, we issued a warrant to purchase 150,000 shares of our common stock as compensation for services rendered. The warrant had an exercise price of $6.63 per share and a term of three years. The grant date fair value of $442 was determined using the Black-Scholes model. Key assumptions used in the model included a risk-free rate of 0.7%, expected volatility of 67%, and an expected term of three years.
	On July 8, 2013, we issued a warrant to purchase 12,500 shares of our common stock as compensation for services. The warrant has an exercise price of $4.15 per share and an expiration date of July 8, 2016. The grant date fair value of $22 was determined using the Black-Scholes model. Key assumptions used in the model included a risk-free rate of 0.7%, expected volatility of 66%, and an expected term of 3 years.
	On January 8, 2013, we issued a warrant to purchase 12,500 shares of our common stock as compensation for services. The warrant has an exercise price of $3.56 per share and an expiration date of January 8, 2016. The grant date fair value of $24 was determined using the Black-Scholes model. Key assumptions used in the model included a risk-free rate of 0.1%, expected volatility of 75%, and an expected term of 3.5 years.
	On July 11, 2012, we issued a warrant to purchase 150,000 shares of our common stock under an existing consulting agreement as compensation for services rendered. The warrant had an exercise price of $5.28 per share and a term of five years. The grant date fair value of $406 was determined using the Black-Scholes model. Key assumptions used in the model included a risk-free rate of 0.6%, expected volatility of 79%, and an expected term of 5 years.
	On July 3, 2012, we issued 38,977 shares of common stock to non-employee directors in lieu of cash payments for compensation of services rendered. The fair value of the shares issued was $194 based on the closing price of our common stock on the transaction date.
	On June 29, 2012, we issued 312,500 shares of common stock as compensation for services rendered in relation to the Apollo agreement. The fair value of the shares issued was $1,563 based on the closing price of our common stock on the transaction date.
	On January 1, 2012, we issued 30,000 shares of common stock to a non-employee as compensation for services. The fair value of the shares issued was $100 based on the closing price of our common stock on the transaction date.
	On August 4, 2011, we issued 100,000 shares of common stock under an existing consulting agreement as compensation for services rendered. The fair value of the shares issued was $300 based on the closing price of our common stock on the transaction date.
	On May 20, 2011, we issued a warrant to purchase 300,000 shares of our common stock as compensation for services. The warrant had an exercise price of $5.51 per share and an expiration date of May 20, 2016. The grant date fair value of $1,100 was determined using the Black-Scholes model. Key assumptions used in the model included a risk-free rate of 1.8%, expected volatility of 86%, and an expected term of 5 years.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Apr. 30, 2014
Share-based Compensation [Abstract]	'
Stock-Based Compensation	'
	STOCK-BASED COMPENSATION
	During fiscal years 2010 and 2011, our Compensation Committee and Board of Directors adopted share-based compensation plans authorizing 3,000,000 and 8,250,000 shares of common stock under each plan, respectively. On April 16, 2014, the number of shares of common stock available for issuance increased by 5,000,000 shares of common stock under the 2011 compensation plan. The increase was adopted by our Board of Directors on March 10, 2014, and approved by our shareholders on April 16, 2014. The share-based compensation plans allow us to offer our employees, officers, directors and others an opportunity to acquire a proprietary interest in the Company and enable us to attract, retain, motivate and reward such persons in order to promote the success of the Company. Each plan authorizes the issuance of incentive stock options, nonqualified stock options and restricted stock.  All awards issued under the share-based compensation plans must be approved by our Compensation Committee. At April 30, 2014 and 2013, there were 3,134,578 and 329,328 additional shares available under the compensation plans, respectively.
	We recorded $4,298, $8,791 and $12,545 of employee compensation expense related to stock options during the years ended April 30, 2014, 2013 and 2012, respectively. The grant date fair value of employee stock options and warrants granted during the years ended April 30, 2014, 2013 and 2012 was $5,513, $1,847 and $13,839, respectively. The weighted average grant date fair value of employee stock options and warrants granted during the 2014, 2013 and 2012 fiscal years was $3.16, $2.73 and $3.40, respectively. We estimated the grant date fair value of employee stock options and warrants using the Black-Scholes pricing model with the following weighted average assumptions:
		2014		2013		2012
	Risk-free interest rate	1.90%		0.80%		1.40%
	Term (in years)	5.8		5.8		4.7
	Volatility	70%		83%		83%
	Dividend yield	—%		—%		—%
	Risk-free interest rate:
	The risk-free rate for the expected term of the option is based on the U.S. Treasury yield curve at the date of grant.
	Expected term:
	We use the simplified method to estimate the expected term of stock options due to the fact we experienced significant structural changes to our business in connection with the December 2009 acquisition of our Alaska properties.  Due to these significant structural changes we do not believe that our historical exercise data provides a reasonable basis for estimating the expected term for the current share options granted.  The simplified method assumes that employees will exercise share options evenly between the period when the share options are vested and ending on the date when the share options would expire.
	Expected volatility:
	In addition to our own historical volatility, we also consider the implied volatility of our options to estimate our future volatility.  This is due to the fact that we do not believe that our historical volatility is the best indicator of future volatility.  Accordingly, we have weighted both our historical volatility and our implied volatility to estimate our future volatility. Our historical volatility was considered for all grant dates subsequent to March 22, 2010, which is the date we filed our Form 10-Q for the third quarter ended January 31, 2010, which is the first filing that reported the financial impact of the Alaska business combination.
	Expected dividend:
	We have not estimated any dividend yield as we currently do not pay a dividend and do not anticipate paying a dividend over the expected term.
	During the years ended April 30, 2014, 2013 and 2012, we also recorded $1,103, $2,154 and $1,501 of non-employee equity related expense for services, respectively. These expenses are included in general and administrative expenses in our consolidated statements of operations. The grant date fair value of non-employee awards granted during 2014, 2013 and 2012 was $1,671, $431 and $1,119, respectively. The weighted average grant date fair value of non-employee awards issued for services during the 2014, 2013 and 2012 fiscal years was $2.73, $2.65 and $3.73, respectively.
	We estimated the grant date fair value of non-employee stock awards issued for services using the Black-Scholes pricing model with the following weighted average assumptions:
		2014		2013		2012
	Risk-free interest rate	1.80%		0.60%		1.80%
	Term (in years)	5.8		4.9		5
	Volatility	70%		79%		86%
	Dividend yield	—%		—%		—%
	The following table summarizes our stock-based compensation activities for the years ended April 30, 2014, 2013 and 2012:
		2014						2013					2012
		Number of Options and Warrants			Weighted Average Exercise Price			Number of Options and Warrants		Weighted Average Exercise Price			Number of Options and Warrants		Weighted Average Exercise Price
	Balance at beginning of year	14,403,847			$	4.61		15,405,955		$	4.6		11,079,955		$	3.98
	Granted	2,357,500			5.7			966,750		4.34			5,345,000		5.34
	Exercised	(1,681,654	)		2.76			(1,286,001	)	2.98			(969,000	)	1.43
	Canceled	(58,346	)		4.27			(682,857	)	5.33			(50,000	)	5.94
	Balance at end of year	15,021,347			4.99			14,403,847		4.61			15,405,955		4.6
	Options exercisable at April 30	10,621,164			$	4.73		9,821,403		$	4.25		8,268,459		$	3.78
	The following table summarizes our stock options and warrants outstanding, including exercisable shares at April 30, 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		1,506,400			1.2	$	0.7		1,506,400		$	0.7
	$2.00 to $4.99		1,783,000			5.4	3.55			1,391,154		3.39
	$5.25 to $5.53		4,491,947			3.4	5.32			2,636,947		5.32
	$5.89 to $5.94		3,295,000			6.4	5.92			2,936,663		5.93
	$6.00 to $6.95		3,945,000			3.6	6.13			2,150,000		6.08
			15,021,347			4.1	$	4.99		10,621,164		$	4.73
	The following table summarizes restricted stock activity for the years ended April 30, 2014, 2013 and 2012:
		2014			2013		2012
	Unvested at beginning of year	591,030			147,000		97,000
	Granted	520,000			997,172		130,000
	Vested	(630,348	)		(536,142	)	(75,000	)
	Forfeited	(15,250	)		(17,000	)	(5,000	)
	Unvested at end of year	465,432			591,030		147,000
	The aggregate intrinsic value of stock options and warrants exercised during the years ended April 30, 2014, 2013 and 2012 was $3,533, $1,201 and $3,782, respectively. The aggregate intrinsic value was calculated as the difference between the exercise price of the underlying awards and the quoted price of our common stock for those awards that had an exercise price below the quoted price on the exercise date. During the years ended April 30, 2014, 2013 and 2012, we received cash of $4,638, $3,832 and $1,383 for options and warrants exercised, respectively. As of April 30, 2014, we have employee-related unrecognized stock-based compensation expense of $7,931 with a weighted average vesting term of 1.33 years, over which the expense will be recognized. The impact on our basic loss per common share that resulted from employee stock-based non-cash compensation is $0.17, $0.21 and $0.31 for the years ended April 30, 2014, 2013 and 2012, respectively.

Litigation

Litigation	12 Months Ended
	Apr. 30, 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, arose from the same allegations as the previous action in the state court.  The federal case sought money damages from us for breach of contract; however, unlike the previous action, it did not seek specific performance of the assignments at issue.  The Plaintiff claimed 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 in other income (expense), net in its consolidated statement of operations for the year ended April 30, 2014 in connection with this settlement.
	On May 17, 2011, we were served with a lawsuit filed in the United States District Court for the Eastern District of Tennessee at Knoxville by Troy D. Stafford, the former Chief Financial Officer of CIE.  The suit, styled Troy D. Stafford v. Miller Petroleum, Inc., Civil Action No. 3-11CV-206, claims that we terminated Mr. Stafford's employment without cause in contravention of the terms of the Purchase and Sale Agreement between us and the sellers of CIE ("PSA"), failed or refused to pay his salary, severance, percentage of purchase price, expenses or stock warrants and violated a duty of good faith and fair dealing. The suit sought damages in excess of $3,000, which includes $2,687 of damages for loss of vested warrants. We believe that all of the asserted claims were baseless, particularly in view of the fact that we issued the warrants in accordance with the terms of the PSA.  We believe that we had appropriate cause to dismiss Mr. Stafford's employment after discovering that he had breached certain representations and warranties in the PSA, and had acted in violation of our Code of Conduct. We filed our Answer and conducted discovery. On January 21, 2013, Mr. Stafford's attorney filed a motion to withdraw as counsel, and on April 2, 2013, Mr. Stafford filed a motion to proceed pro se. On February 24, 2014, we filed a Motion to Dismiss with Prejudice based on Plaintiff’s failure to prosecute his case since April 2, 2013, Plaintiff’s having missed filing deadlines, and his having failed to appear to give his deposition both times we have noticed it. On February 26, 2014, the Court entered an Order to Show Cause, requiring the plaintiff to demonstrate why his case should not be dismissed. On March 14, 2014, the plaintiff filed a Motion for Voluntary Dismissal, Without Prejudice through his new attorney. On June 3, 2014, the court granted plaintiff’s motion to dismiss without prejudice, but did so with the condition that plaintiff must reimburse us for costs incurred by us as a result of his failure to cooperate in discovery in this case in the amount of $9 prior to his being allowed to refile the case. As such, this case has been dismissed and there is no further action currently required.
	On June 15, 2011, a breach of contract lawsuit was filed against us and CIE in the United States District Court for the Eastern District of Pennsylvania styled VAI, Inc. v. Miller Energy Resources, Inc., f/k/a Miller Petroleum, Inc. and Cook Inlet Energy, LLC. The Plaintiff alleges three causes of action: (1) breach of contract, (2) unjust enrichment, and (3) breach of the implied covenant of good faith and fair dealing. The case seeks damages in warrants to purchase our common stock and monetary damages for certain fees and expenses. The Sale Agreement with David Hall, Walter "JR" Wilcox, and Troy Stafford dated December 10, 2009 contains indemnification provisions relevant to this claim. We filed a Motion to Dismiss for lack of personal jurisdiction, but this motion was not granted by the court. We filed an Answer to the complaint in this case on October 10, 2012, and we have conducted discovery. Trial was previously set for November 4, 2013. On October 21, 2013, the trial was postponed with no new trial date having been set. On October 31, 2013, the judge ruled on our outstanding Motion for Summary Judgment, granting it as to the unjust enrichment claim and breach of the implied covenant of good faith and fair dealing claim, and denying it as to the breach of contract claim. We expect to proceed to trial on the breach of contract claim once a new trial date is set. In February 2014, we received notice from a third party seeking to intervene in the case in order to secure payment of a debt allegedly owed by the Plaintiff to the third party. On June 5, 2014, the court entered an order denying the motion to intervene. On May 29, 2014, the court put down a new scheduling order setting forth certain pre-trial deadlines with the final pre-trial conference being set for October 30, 2014. We expect the court to set a trial date that will be shortly after the final pre-trial conference. 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. On July 3, 2014, we agreed upon a potential settlement with the Plaintiffs would dismiss the lawsuit with prejudice in exchange for a settlement payment of $2,950, which is within the remaining policy limits of our director and officer insurance policy. The proposed settlement remains subject to court approval and class notice administration before it will be effective.  We expect to complete full documentation of the settlement and file a motion for preliminary approval of the class action settlement and approval of the class no later than August 31, 2014.
	On August 23, 2011, a derivative action was filed against us in Knox County Chancery Court.  The case is styled Marco Valdez, derivatively on behalf Miller Energy Resources, Inc. v. Deloy Miller, Scott M. Boruff, Jonathan S. Gross, Herman Gettelfinger, David Hall, Merrill A. McPeak, Charles M. Stivers, Don A. Turkleson, and David J. Voyticky, and Miller Energy Resources, Inc., nominal defendant.  The suit alleged the following causes of action: (1) Breach of Fiduciary Duty for disseminating false and misleading information; (2) Breach of Fiduciary Duty for failure to maintain internal controls; (3) Breach of Fiduciary Duty for failing to properly oversee and manage the company; (4) Unjust Enrichment; (5) Abuse of Control; Gross Mismanagement, and; (6) Waste of Corporate Assets.  The Plaintiff sought unspecified money damages from the individual defendants, that we take certain actions with respect to our management, restitution to us, and the Plaintiff's attorney fees and costs. The Plaintiff agreed to stay this case awaiting a ruling on the plaintiff's appeal in the federal derivatives case in Lukas v. Miller Energy Resources, Inc., et al, as described in the next paragraph. The Plaintiff also agreed to voluntarily dismiss the case in the event the plaintiff's appeal in Lukas was denied. Following the dismissal of Lukas, on October 1, 2013, the Court entered an Order dismissing the 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 June 3, 2014, after reaching an agreement with the Plaintiff, we filed an amended agreed final order of dismissal with prejudice in this case.
	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, and 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. 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. The Court denied the motion on January 8, 2014. The Plaintiffs had three months to file a petition to the Supreme Court of the United States, but did not do so. Therefore, these cases have ended.
	On August 31, 2012, we terminated an agreement with Voorhees Equipment and Consulting, Inc. (“Voorhees”) for the construction and sale of the rig currently being used on the Osprey Platform, Rig 35, (the “Rig 35 Agreement”). We terminated the agreement based on our belief that Voorhees was in breach of its obligations thereunder.  Voorhees later indicated its desire to arbitrate claims it believes it has under invoices arising between May 29, 2012 and August 31, 2012.  We believed we had grounds to dispute liability with respect to some or all of those invoices, in addition to having certain counterclaims we expected to assert.  The parties elected to engage a private arbitrator to settle this dispute (the “Voorhees Matter”) and conducted discovery.  On September 18, 2013, we received a third-party complaint from Voorhees in connection with a lawsuit by Carlile Transportation Systems, Inc., in the Superior Court for the State of Alaska. The case is styled Carlile Transportation Systems, Inc. v. Voorhees Rig International, Inc. v. Cook Inlet Energy, LLC (the “Carlile Matter”). The dispute in the Carlile Matter related solely to unpaid transportation fees arising from the transportation of equipment for Rig 35. These fees were already the subject of the planned arbitration with Voorhees over the Voorhees Matter. As all disputes under the Rig 35 Agreement are subject to mandatory arbitration, we filed a motion to compel arbitration in the Carlile Matter, which the Court granted, along with an award of our legal costs incurred in connection with the Carlile Matter. On February 20, 2014, we reached an agreement in principle to settle the Voorhees Matter (including the transportation fees at issue in the Carlile Matter), and we entered into a settlement agreement which was effective as of May 12, 2014. We agreed to return to Voorhees the following equipment previously delivered to us under the Rig 35 Agreement, but which we subsequently replaced on that rig:
	•	An iron roughneck that we had to replace on Rig 35 due to mechanical unreliability; and
	•	A BOP stack originally included on Rig 35, but later removed and replaced with a better functioning replacement.
	We also agreed to return to Voorhees two moving containers, left-over electrical equipment and tools belonging to Voorhees but left with CIE when Voorhees ceased working on Rig 35. No costs of defense or other cash payment are expected to be required of us in connection with this settlement, although we will pay the transportation costs of the equipment being returned. Accordingly, we have accrued our best estimate, based on the terms in the settlement agreement, of the potential loss on our consolidated balance sheet.
	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 warrant 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 we have filed a Motion to Transfer as the warrants have a valid exclusive forum clause that requires the case be tried in Knox County, Tennessee. 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.

Fair_Value_Measurements_Fair_V

Fair Value Measurements Fair Value Measurements	12 Months Ended
	Apr. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	FAIR VALUE MEASUREMENTS
	Fair Value Measurements on a Recurring Basis
	The carrying amounts reported in the consolidated balance sheets for cash and cash equivalents, trade receivables, account payables and other short-term liabilities approximate fair value due to the nature of the instrument and/or the short-term maturity of these instruments. The fair values of the Company’s commodity derivative instruments are classified as level 2 measurements as they are calculated using industry standard models using assumptions and inputs which are substantially observable in active markets throughout the full term of the instruments. These include market price curves, contract terms and prices, credit risk adjustments, and discount factors. The following summarizes the fair value of the Company’s commodity derivative assets and liabilities according to their fair value hierarchy as of the reporting dates indicated:
		Fair Value Measurements
	At April 30, 2014	Level 1		Level 2			Level 3
	Commodity derivative asset	$	—	$	114		$	—
	Commodity derivative liability	—		(7,321		)	—
	Total	$	—	$	(7,207	)	$	—
	At April 30, 2013
	Commodity derivative asset	$	—	$	—		$	—
	Commodity derivative liability	—		(842		)	—
	Total	$	—	$	(842	)	$	—
	There were no transfers between Level 1, Level 2 or Level 3 during the years ending April 30, 2014 or 2013.

Oil_and_Gas_Properties_and_Equ

Oil and Gas Properties and Equipment	12 Months Ended
	Apr. 30, 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:
		April 30,
		2014			2013
	Property costs
	Proved property	$	467,740		$	332,241
	Unproved property	243,107			196,500
	Total property costs	710,847			528,741
	Less: Accumulated depletion	(66,020		)	(37,427		)
	Oil and gas properties, net	$	644,827		$	491,314
	Equipment is summarized as follows:
		April 30,
		2014			2013
	Machinery and equipment	$	7,759		$	7,413
	Vehicles	1,877			1,851
	Aircraft	—			476
	Buildings	2,726			2,725
	Office equipment	1,108			759
	Leasehold improvements	527			482
	Drilling rigs	30,210			30,117
	Payment on drilling rig	1,500			—
		45,707			43,823
	Less: Accumulated depreciation	(10,338		)	(6,252		)
	Equipment, net	$	35,369		$	37,571
	The Company classified its aircraft as an asset held for sale on our consolidated balance sheet as of April 30, 2014. The aircraft is recorded at estimated fair value less cost to sell. During fiscal 2014, the Company recorded an impairment charge of $168, which is recorded in other operating (income) expense, net on our consolidated statement of operations. Proceeds received from the sale of the aircraft are required to pay down the Company’s Second Lien Credit Facility.
	Depreciation, depletion and amortization consisted of the following:
		For the Year Ended April 30,
		2014			2013			2012
	Depletion of oil and gas related assets	$	29,292		$	9,803		$	12,537
	Depreciation and amortization of equipment	4,236			3,367			773
	Total	$	33,528		$	13,170		$	13,310

Major_Customers_and_Concentrat

Major Customers and Concentrations of Credit Risk	12 Months Ended
	Apr. 30, 2014
Risks and Uncertainties [Abstract]	'
Major Customers and Concentrations of Credit Risk	'
	MAJOR CUSTOMERS AND CONCENTRATIONS OF CREDIT RISK
	During the years ended April 30, 2014, 2013 and 2012, Tesoro accounted for 88%, 80%, and 100% of our consolidated total revenues, respectively. Tesoro also accounted for 5% and 55% of our accounts receivable as of April 30, 2014, and 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 years ended April 30, 2014, 2013 and 2012.
	We maintain our cash and cash equivalents, which at times may exceed federally insured amounts, in highly rated financial institutions. As of April 30, 2014, we held $5,062 in excess of the $250 limit insured by the Federal Deposit Insurance Corporation.
	Derivative assets and liabilities
	We have a risk of loss from counterparties not performing pursuant to the terms of their contractual obligations. We attempt to minimize credit-risk exposure to derivative counterparties through formal credit policies, consideration of credit ratings from public ratings agencies, monitoring procedures, master netting agreements and collateral support under certain circumstances. Collateral support could include letters of credit, payment under margin agreements and guarantees of payment by credit worthy parties.
	We also enter into master netting agreements to mitigate counterparty performance and credit risk. During the years ending April 30, 2014, 2013, and 2012, we did not incur any significant losses due to counterparty bankruptcy filings. We assess our credit exposure on a net basis to reflect master netting agreements in place with certain counterparties. We offset our credit exposure to each counterparty with amounts we owe the counterparty under derivative contracts.

Alaska_Production_Credits

Alaska Production Credits	12 Months Ended
	Apr. 30, 2014
Alaska Production Credits [Abstract]	'
Alaska Production Credits	'
	ALASKA PRODUCTION CREDITS
	During the years ended April 30, 2014 and 2013, the Company qualified for several credits under Alaska Statutes 43.55.023 and 43.55.025:
	•	43.55.023(a)(1) Qualified capital expenditure credit (20%)
	•	43.55.023(l)(1) Well lease expenditure credit (effective June 30, 2010) (40%)
	•	43.55.023(a)(2) Qualified capital exploration expenditure credit (20%)
	•	43.55.023(l)(2) Well lease exploration expenditure credit (effective June 30, 2010) (40%)
	•	43.55.023(b) Carried-forward annual loss credit (25%)
	•	43.55.025 Seismic exploration credits (40%)
	We recognize a receivable when the amount of the credit is reasonably estimable and receipt is probable. For expenditure and exploration based credits, which we receive in the ordinary course of business, the credit is recorded as a reduction to the related assets. For carried-forward annual loss credits, which we receive in the ordinary course of business, the credit is recorded as a reduction to the Alaska production tax. We did not incur any Alaska production taxes in fiscal 2014, 2013 or 2012, and accordingly, the carried-forward annual loss credits are presented separately in our operating expenses on the consolidated statement of operations.
	Balance, April 30, 2013	$	12,713
	Applications for carried-forward annual loss credits1	16,342
	Applications for expenditure and exploration based credits1	41,841
	Cash collections for carried-forward annual loss credits	(3,244		)
	Cash collections for expenditure and exploration based credits	(18,531		)
	Balance, April 30, 2014	$	49,121
	————————
	1	Applications for carried-forward annual loss credits for expenditure and exploration based credits are recorded net of established reserves and also include revisions to prior period applications, if applicable.
	During the years ended April 30, 2014, 2013 and 2012, the Company recorded net carried-forward annual loss credits of $16,342, $3,268 and $0, respectively. As of April 30, 2014 and 2013, the Company has reduced the basis of capitalized assets by $54,570 and $14,547 for expenditure and exploration credits. The reductions are recorded on our consolidated balance sheets in "oil and gas properties" and "equipment." As of April 30, 2014 and 2013, the Company had outstanding net receivables from the State of Alaska in the amount of $49,121 and $12,713, respectively.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Apr. 30, 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 COO of Miller, as well as the Chief Executive Officer ("CEO") of CIE. For fiscal 2014, 2013 and 2012, we paid H&H Industrial a total of $2,003, $1,024 and $632, 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 fiscal 2014, 2013 and 2012, we paid Rediske Air, Inc. a total of $1,060, $680 and $463, 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.
	From time to time the Company provides service work on oil and gas wells owned by Mr. Herman Gettelfinger (and family), a member of the Board of Directors until April 16, 2014 and an emeritus member of the Board from that date until his death on May 17, 2014. As of April 30, 2014 and 2013, Mr. Gettelfinger (and family) owed us $24 and $11, respectively. The audit committee of our Board of Directors determined that the amounts paid to us for the services performed were fair and in the best interests of the Company.
	During fiscal 2014, Mr. Gettelfinger paid the Company $3 for the profit he made from the purchase and sale of our common stock within a six month period. The $3 proceeds are presented in other cash flows from financing activities in our consolidated statements of cash flows.
	The Company is required to remit payroll taxes related to certain stock-based compensation transactions. As of April 30, 2014, we had a payable of $157 and no receivable. As of April 30, 2013, we had recorded a related payable of $620 as well as a corresponding receivable from the respective employees of $593. This receivable was collected subsequent to April 30, 2013.
	In 2009 we formed both Miller Energy GP and MEI to raise capital necessary to support strategic business initiatives. From November 2009 to May 2010 we entered into the MEI Loan Documents 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, (i) the later of 91 days after the date on which the Prior Credit Facility is extinguished, or (ii) July 31, 2017. Our wholly owned subsidiary, Miller Energy GP, owned 1% of MEI, however due to the shared management of our company and MEI, we have consolidated this entity. We have not presented noncontrolling interest on our consolidated balance sheets or our consolidated statements of operations due to the fact that these amounts are immaterial. On February 3, 2014, we repaid all obligations under and terminated the MEI Loan Documents. Once paid, in accordance with the governing documents of MEI, the interests of the limited partners in MEI were effectively redeemed and ceased to exist. As a result, under Delaware law, MEI ceased to be a “limited partnership” when no new limited partners were admitted within the statutorily prescribed time limit. As the Company was the sole general partner and sole remaining holder of any equity interest in MEI, MEI has therefore been legally consolidated into the Company. We are in the process of preparing a certificate of cancellation for filing with the State of Delaware with respect to MEI.
	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. As of April 30, 2014, we paid Mr. Weakley a total of $5.
	Two adult children of our Chief Operating Officer, Mr. David Hall, are non-executive employees of CIE.  During the year ended April 30, 2014, their compensation exceeded $120 and thereby required review by the Audit Committee and disclosure herein.  Mr. Hall’s sons earned $161 and $148, respectively, during fiscal 2014.  Their compensation was determined in accordance with our standard employment and compensation practices applicable to employees with similar responsibilities and positions.

Subsequent_Events

Subsequent Events	12 Months Ended
	Apr. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	SUBSEQUENT EVENTS
	Acquisition of Rig 36 and Related Capital Lease
	On May 5, 2014, we entered into the Rig Equipment Purchase Agreement with Baker Process, Inc. to purchase the Company's Rig 36 and related equipment. Subsequent to purchasing Rig 36, on May 9, 2014, the Company entered into a capital lease with First National Capital, LLC to finance the purchase of and planned future modifications to Rig 36. As of July 7, 2014, we have drawn $3,250 under the capital lease, which can be expanded to $5,000 as we continue to upgrade Rig 36.
	Entry into Merger Agreement with Savant Alaska, LLC
	On May 8, 2014, we entered into the Merger Agreement to acquire Savant, subject to due diligence and regulatory approval, for $9,000. We have formed a wholly-owned subsidiary, Miller Colorado, which will merge with Savant to facilitate the acquisition. Savant currently owns, and we would indirectly acquire as a result of this merger of Miller Colorado with Savant, a 67.5% working interest in the Badami Unit and 100% ownership in certain nearby leases. ASRC Exploration, LLC owns the remaining 32.5% working interest in the Badami Unit. In addition to the working interest in the Badami Unit and the leases, we would acquire certain midstream assets located in the North Slope with a design capacity of 38,500 bopd, a 500,000 gallon diesel storage tank, 20 megawatts of power generation, a grind and inject solid waste disposal facility and Class 1 disposal well, a one mile airstrip, and two pipelines each running 25 miles in length from Badami to the Endicott Pipeline. Current production from the Savant assets is approximately 1,100 bopd gross (600 bopd net).
	We expect the transaction to close following receipt of regulatory approval, which we expect will be received by the end of December 2014. The merger will have an effective date of May 1, 2014.
	Entry into First Lien RBL
	On June 2, 2014, we entered into the First Lien Loan Agreement, among the Company, as borrower, KeyBank, as the RBL Administrative Agent, and the RBL Lenders. In addition to KeyBank, the syndicate includes CIT Finance LLC, Mutual of Omaha Bank and OneWest Bank N.A.
	The First Lien Loan Agreement provides for a $250,000 senior secured, reserve-based revolving credit facility, $60,000 of which was made available to us on the closing date. Amounts outstanding under the First Lien RBL are priced on a sliding scale, based on LIBOR plus 300 to 400 basis points and an undrawn commitment fee, depending upon the level of borrowing (per the table below).
	Borrowing Base Utilization Grid
	Borrowing base utilization percentage	<25%	≥ 25%, but <50%	≥ 50%, but <75%	≥ 75%, but <90%	≥ 90%, but ≤100%
	Spread above LIBOR	3.00%	3.25%	3.50%	3.75%	4.00%
	Undrawn commitment fee rate	0.50%	0.50%	0.75%	0.75%	0.75%
	The First Lien RBL will expire on the third anniversary of the closing. The facility includes contains customary covenants, including a leverage, interest coverage, current ratio, minimum gross production, minimum liquidity, asset coverage and change of management control covenants as well as other covenants customary for a transaction of this type.  Subject to certain conditions contained in the First Lien Loan Agreement, the First Lien RBL also allows us to implement a discretionary share repurchase plan on terms and conditions reasonably satisfactory to the RBL Administrative Agent and the RBL Lenders. The First Lien RBL contemplates up-front fees, arrangement fees, and ongoing commitment and other fees customary for transactions of this nature.
	The Company drew $20,000 on the closing date under the First Lien RBL, which will be used to provide working capital for development drilling in Alaska. The amounts drawn were subject to an original issue discount equal to 1% of the initial borrowing base. On June 24, 2014, we drew an additional $10,000 under the First Lien RBL.
	Also on June 2, 2014, in connection with the First Lien RBL, the Company, along with all of its consolidated subsidiaries (other than MEI, Miller Energy, and Miller Energy Drilling 2009-A, L.P.), entered into a First Lien Guarantee and Collateral Agreement with KeyBank, for the benefit of the RBL Lenders from time to time party to the First Lien Loan Agreement. Under the terms of the First Lien Guarantee and related security documents each of the consolidated subsidiaries of the Company (other than MEI, Miller Energy Colorado, and Miller Energy Drilling 2009-A, L.P.) have guaranteed the our obligations under the First Lien RBL and we and those subsidiaries have granted a security interest in substantially all of our assets to secure the performance of the obligations arising under the First Lien RBL.
	Amendment of New Apollo Loan Agreement
	On June 2, 2014, we entered into the Amendment No. 1 to Credit Agreement and Guarantee and Collateral Agreement to the Second Lien Credit Facility and the Second Lien Guarantee. This amendment conforms certain of the covenants, terms and conditions in the Second Lien Credit Facility to match those of the First Lien RBL, including the financial covenants.
	Payment of Dividends
	On June 2, 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 March 1, 2014 through May 30, 2014. The record date was May 15, 2014.
	On June 2, 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 March 1, 2014 through May 30, 2014. The record date was May 15, 2014.
	Intended Disposition of Tennessee Assets
	On June 24, 2014, we announced our intent to divest our Tennessee assets in order to allocate our capital to our Alaskan operations and investment opportunities. No definitive agreement has been reached with any potential buyer in connection with this proposed transaction and, until that has occurred, we will continue to conduct our business as usual in Tennessee.
	Proposed Class Action Settlement
	On July 3, 2014, we agreed upon a potential settlement with the Plaintiffs in the purported class action lawsuit styled In re Miller Energy Resources, Inc. Securities Litigation wherein the Plaintiffs would dismiss the lawsuit with prejudice in exchange for a settlement payment of $2,950, expected to be funded by our director and officer insurance policy. The proposed agreement, when and if it becomes effective, would not be an admission of wrongdoing or acceptance of fault by us or any of the individual defendants named in the complaint. We, along with those individual defendants, have agreed upon the terms of this proposed settlement to eliminate the uncertainties, risk, distraction and expense associated with protracted litigation. The proposed settlement remains subject to court approval and class notice administration before it will be effective.  We expect to complete full documentation of the settlement and file a motion for preliminary approval of the class action settlement and approval of the class no later than August 31, 2014. The estimated potential loss and expected insurance recovery are accrued on our consolidated balance sheet as of April 30, 2014.
	Entry into Glacier Rig Purchase Option
	Effective as of July 4, 2014, we entered into a Purchase and Sale Agreement with Teras which grants us the right to purchase the Glacier Rig and the Glacier PSA. The Glacier PSA is dated as of July 3, 2014, but was signed by Teras the following day. A payment of $700 was required in connection with the execution and delivery of the Glacier PSA, which we are entitled to have refunded if we fail to close by August 8, 2014, if it should be determined that Teras lacks clear title to the Glacier Rig, there are liens or encumbrances (other than immaterial defects in title or liens to which we consented) or if the Glacier Rig is affected by a significant casualty prior to closing. An additional payment of $6,300 will be due if the sale is finalized.

Supplemental_Oil_and_Gas_Discl

Supplemental Oil and Gas Disclosures (Unaudited) Supplemental Oil and Gas Disclosures (Unaudited)	12 Months Ended
	Apr. 30, 2014
Oil and Gas Exploration and Production Industries Disclosures [Abstract]	'
Supplemental Oil and Gas Disclosures (Unaudited)	'
	SUPPLEMENTAL OIL AND GAS DISCLOSURES (UNAUDITED)
	The following tables show our capital and operational costs for fiscal years 2014, 2013 and 2012:
	a. Capitalized Costs Relating to Oil and Gas Producing Activities at April 30, 2014, 2013 and 2012 are as follows:
		2014				2013				2012
	Natural gas and oil properties:
	Proved properties	$	467,740			$	332,241			$	321,066
	Unproved properties	243,107				196,500				182,704
		710,847				528,741				503,770
	Accumulated depletion	(66,020		)		(37,427		)		(27,968		)
	Net capitalized costs	$	644,827			$	491,314			$	475,802
	b. Costs Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities:
		2014				2013				2012
	Property acquisition costs
	Proved properties	$	54,535			$	689			$	—
	Unproved properties	7,564				704				785
	Acquisition costs	62,099				1,393				785
	Exploration costs	1,713				1,268				180
	Development costs	133,778				24,968				6,773
	Total	$	197,590			$	27,629			$	7,738
	c. Results of Operations for Producing Activities:
		2014				2013				2012
	Production revenues	$	69,469			$	29,915			$	32,493
	Lease operating expense	(20,187		)		(22,288		)		(11,305		)
	Transportation costs	(5,599		)		(2,410		)		(3,556		)
	Alaska carried-forward annual loss credits, net	16,342				3,268				—
	Depletion	(35,212		)		(13,041		)		(13,094		)
	Results of operations for producing activities (excluding corporate overhead and interest costs)	$	24,813			$	(4,556	)		$	4,538
	d. Reserve Quantity Information (Unaudited)
	The following reserve quantity information was derived from reserve and engineering reports prepared for the Company. During the fiscal 2014 year we made a change in our independent reserve engineer from Ralph E. Davis Associates, Inc. to Ryder Scott Company, L.P. for our Alaska properties.  The decrease in PUD volumed resulted primarily from changes in the professional judgment of our independent petroleum engineer, additional production history leading to lower projected recovery estimates and to a lesser extent, changes in price and cost. The reserve and engineering reports for both Alaska and Tennessee properties were prepared by Ralph E. Davis Associates, Inc. for the years ended April 30, 2013 and 2012.
	The following schedule estimates proved oil and natural gas reserves attributable to the Company. Proved reserves are estimated quantities of oil and natural gas which geological and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions. Proved developed reserves are those which are expected to be recovered through existing wells with existing equipment and operating methods. Reserves are stated in barrels of oil (Bbls) and thousands of cubic feet of natural gas (Mcf). Geological and engineering estimates of proved oil and natural gas reserves at one point in time are highly interpretive, inherently imprecise and subject to ongoing revisions that may be substantial in amount. Although every reasonable effort is made to ensure that the reserve estimates reported represent the most accurate assessments possible, these estimates are by their nature generally less precise than other estimates presented in connection with financial statement disclosures.
		Oil (MBbls)			Gas (MMcf)			MBoe
	Proved reserves
	Balance, April 30, 2011	8,948			3,243			9,489
	Extensions, discoveries and other additions	94			1,850			402
	Revisions of previous estimates	(124	)		(359	)		(183	)
	Acquisition of reserves in place	—			—			—
	Production	(384	)		(177	)		(414	)
	Balance, April 30, 2012	8,534			4,557			9,294
	Extensions, discoveries and other additions	26			35			32
	Revisions of previous estimates	(317	)		(519	)		(404	)
	Acquisition of reserves in place	6			—			6
	Production	(295	)		(133	)		(317	)
	Balance, April 30, 2013	7,954			3,940			8,611
	Extensions, discoveries and other additions	2,113			—			2,113
	Revisions of previous estimates	(3,286	)		(231	)		(3,325	)
	Acquisition of reserves in place	—			24,726			4,121
	Production	(685	)		(794	)		(817	)
	Balance, April 30, 2014	6,096			27,641			10,703
	Proved developed reserves at April 30, 2012	2,325			2,601			2,759
	Proved developed reserves at April 30, 2013	1,697			513			1,783
	Proved developed reserves at April 30, 2014	4,264			12,202			6,298
	Proved undeveloped reserves at April 30, 2012	6,209			1,956			6,535
	Proved undeveloped reserves at April 30, 2013	6,257			3,427			6,828
	Proved undeveloped reserves at April 30, 2014	1,832			15,439			4,405
	We acquired 13,273 MMcf of proved undeveloped gas in the North Fork Acquisition that closed on February 4, 2014. As a result of ongoing drilling and completion activities during 2014, the Company reported extensions and discoveries, of 2,113 MBbls mainly with the Sword prospect within the West Macarthur area. The downward revisions were primarily driven by a decrease in PUD volumes. During the fiscal 2014 year we made a change in our independent reserve engineer from Ralph E. Davis Associates, Inc. to Ryder Scott Company, L.P. The decrease in PUD volumes resulted primarily from changes in the professional judgment of our independent petroleum engineer, and to a lesser extent, changes in price and cost.
	The following schedule presents the standardized measure of estimated discounted future net cash flows from the Company's proved reserves for the years ended April 30, 2014, 2013 and 2012. All estimates were prepared by third party reserve and engineering firms. Because the standardized measure of future net cash flows was prepared using the prevailing economic conditions existing at April 30, 2014, 2013 and 2012, it should be emphasized that such conditions continually change. The Company emphasizes that reserve estimates are inherently imprecise and that estimates of new discoveries and undeveloped locations are more imprecise than estimates of established proved producing oil and gas properties. Accordingly, these estimates are expected to change as future information becomes available.
	Each of the engineering reports also projected future cash flows from our net reserves and the present value, discounted at 10% per annum. Future cash flows are based upon gross income from future production, less direct operating expenses and taxes. Estimated future capital for development costs was also deducted from gross income at the time it will be expended. No allowance was made for depletion, depreciation, income taxes or administrative expense. In the following table, the price per barrel of oil was $102.21 and the price per MMcf of natural gas was $6.90 for the Cook Inlet reserves and $86.37 per barrel of oil and $2.27 per MMcf of natural gas for the Appalachian region reserves. In each instance these prices are computed in accordance with the SEC’s rule and represent the average fiscal year prices. All of the Company's reserves are located in the United States.
	Operating costs and production taxes are estimated based on current costs with respect to producing gas properties. Future development costs are based on the best estimate of such costs assuming current economic and operating conditions.
	Income tax expense is computed based on applying the appropriate statutory tax rate to the excess of future cash inflows less future production and development costs over the current tax basis of the properties involved. For purposes of the Standardized Measure calculation, it was assumed that our NOLs, attributable to our oil and gas assets, will be realized within future carryforward periods.
	The future net revenue information assumes no escalation of costs or prices, except for gas sales made under terms of contracts which include fixed and determinable escalation. Future costs and prices could significantly vary from current amounts and, accordingly, revisions in the future could be significant.
	Standardized measures of discounted future net cash flows at April 30, 2014, 2013 and 2012 are as follows:
		2014				2013				2012
	Future cash flows	$	810,184			$	801,134			$	894,027
Future production costs and taxes	(218,407		)		(178,779		)		(158,938		)
Future development costs	(90,812		)		(72,434		)		(75,332		)
Future income tax expense	(117,263		)		(150,568		)		(217,312		)
Future cash flows	383,702				399,353				442,445
Discount at 10% for timing of cash flows	(99,574		)		(124,905		)		(139,242		)
Discounted future net cash flows from proved reserves	$	284,128			$	274,448			$	303,203
The following table sets forth the changes in the standardized measure of discounted future net cash flows from proved reserves for April 30, 2014, 2013 and 2012.
	April 30,
	2014				2013				2012
Balance, beginning of year	$	274,448			$	303,203			$	206,801
Sales, net of production costs and taxes	(43,683		)		(5,217		)		(17,632		)
Changes in prices and production costs	(45,258		)		(59,253		)		116,689
Extensions, discoveries and other additions	100,868				1,302				58,906
Acquisition of reserves in place	73,946				295				—
Changes in estimated future development costs	11,744				(2,856		)		7,641
Development costs incurred	10,131				5,522				6,773
Revisions of previous quantity estimates	(143,565		)		(21,828		)		(42,857		)
Net changes in income taxes	15,502				49,486				(48,571		)
Sales of reserves in place	—				—				—
Accretion of discount	37,176				39,472				30,503
Changes in timing and other	(7,181		)		(35,678		)		(15,050		)
Balance, end of year	$	284,128			$	274,448			$	303,203

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Apr. 30, 2014
Accounting Policies [Abstract]	'
Principles of Consolidation	'
	Principles of Consolidation
	The accompanying consolidated financial statements include the accounts of Miller Energy Resources, Inc. and our wholly owned subsidiaries (collectively, the "Company"). The 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. All intercompany balances and transactions are eliminated in the consolidation.
Reclassifications	'
	Reclassifications
	Certain amounts in prior fiscal years have been reclassified to conform with the presentation adopted in the current fiscal year.
	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 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
Risks and Uncertainties	'
	Risks and Uncertainties
	Factors that could affect our future operating results and cause actual results to vary materially from management's expectation include, but are not limited to: the capital intensive nature of our business and our ability to maintain and secure adequate capital to fully develop our operations and assets; our ability to perform under the terms of the Alaska Oversight Agreement with the Alaska DNR, including meeting the funding requirements of that agreement; the imprecise nature of our reserve estimates; our ability to recover proved undeveloped reserves and convert probable and possible reserves to proved reserves; fluctuating oil and natural gas prices; changes in environmental or regulatory requirements; our ability to control expenses; our ability to comply with covenants related to our credit facilities; and the impact of changes in accounting principles. Negative developments in these or other risk factors could have a significant adverse effect on our financial position, results of operations and cash flows.
Use of Estimates	'
	Use of Estimates
	The preparation of consolidated financial statements in conformity with GAAP requires us to make a number of estimates and assumptions relating to the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. We base our estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about carrying values of assets and liabilities that are not readily apparent from other sources. We evaluate our estimates and assumptions on a regular basis. Actual results may differ from these estimates and assumptions used in preparation of its financial statements and changes in these estimates are recorded when known. Significant estimates made in preparing these financial statements include the fair value determination of acquired assets and liabilities assumed, the estimate of proved oil and gas reserves and related present value estimates of future net cash flows therefrom (see Supplemental Oil and Gas Disclosures (Unaudited)), assessing asset retirement obligations (see Note 5 - Asset Retirement Obligations) and the estimate of income taxes (see Note 7 - Income Taxes).
Cash Equivalents	'
	Cash Equivalents
	We consider all highly liquid short-term investments with a maturity of three months or less at the time of purchase to be cash equivalents. These investments are carried at cost, which approximates fair value due to their short-term nature.
Restricted Cash	'
	Restricted Cash
	As of April 30, 2014 and 2013, current restricted cash includes $38 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. Non-current restricted cash balances include amounts held in escrow to provide for the future plugging and abandonment of wells, dismantling of our off-shore platform, and general liability bonds.
Accounts Receivable and Allowance for Doubtful Accounts	'
	Accounts Receivable and Allowance for Doubtful Accounts
	Accounts receivable are stated at the historical carrying amount net of write-offs and allowance for uncollectible accounts. We routinely assess the recoverability of all material customer and other receivables to determine their collectability and record a reserve when, based on the judgment of management, it is probable that a receivable will not be collected and the amount of the reserve may be reasonably estimated. When collection is no longer pursued, we charge uncollectible accounts receivable against the reserve. As of April 30, 2014 and 2013, we established a reserve of $250 and $0, respectively.
Inventory	'
	Inventory
	Inventory consists of crude oil produced but not sold, stated at the lower of cost or market.
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 depreciated using the unit-of-production method based on estimated total 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 estimated total proved reserves.
	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 established 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. In fiscal 2014, our consolidated statement of operations includes $296 in abandoned leases, $1,695 in seismic and delay rentals incurred in the Cook Inlet region, and $19 related to delay rentals incurred in the Appalachian region.
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.
Capitalized Interest	'
	Capitalized Interest
	Interest is capitalized as part of the historical cost of developing and constructing assets for significant projects. Significant investments in unproved oil and gas properties, significant exploration and development projects for which depreciation, depletion and amortization ("DD&A") is not currently recognized, and exploration or development activities that are in progress qualify for interest capitalization. Interest is capitalized until the asset is ready for service. Capitalized interest is determined based upon our weighted-average borrowing cost on debt for the average amount of qualifying costs incurred. The Company incurred $14,433, $9,289 and $5,500 of interest expense and amortization of deferred financing costs in fiscal years 2014, 2013 and 2012, respectively, of which $8,569, $5,880 and $3,700, respectively, were capitalized in equipment and oil and gas properties on the balance sheet. Once an asset subject to interest capitalization is completed and placed in service, the associated capitalized interest is expensed through DD&A or impairment, along with other capitalized costs related to that asset.
Asset Retirement Obligations	'
	Asset Retirement Obligations
	Asset retirement obligations ("ARO") reflects the estimated present value of the amount of dismantlement, removal, site reclamation, and similar activities associated with our oil and gas properties. We utilize current retirement costs to estimate the expected cash outflows for retirement obligations. We estimate 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.
	The initial estimated ARO is recorded as a liability, with an offsetting asset retirement cost recorded as an increase to the associated property and equipment on the consolidated balance sheet. If the fair value of the recorded ARO changes, a revision is recorded to both the asset retirement obligation and the asset retirement cost. Revisions in estimated liabilities can result from changes in estimated inflation rates, changes in service and equipment costs and changes in the estimated timing of an asset’s retirement. Asset retirement costs are depreciated using a systematic and rational method similar to that used for the associated property and equipment. Accretion expense on the liability is recognized over the estimated productive life of the related assets.
Loss Contingencies	'
	Loss Contingencies
	Accruals for loss contingencies arising from claims, assessments, litigation, environmental and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. These accruals are adjusted as additional information becomes available or circumstances change.
Revenue Recognition	'
	Revenue Recognition
	Oil and natural gas sales revenues are recognized when production is sold to a purchaser at a fixed or determinable price, when delivery has occurred and title has transferred, and if collectability of the revenue is reasonably assured. Cash received relating to future revenues is deferred and recognized when all revenue recognition criteria are met.
Derivative Instruments	'
	Derivative Instruments
	We utilize derivatives to manage our commodity price risk.
	We account for our derivative instruments in accordance with ASC 815, “Derivatives and Hedging,” which requires that all derivative instruments, other than those that meet the normal purchases and sales exception, be recorded on the consolidated balance sheets at fair value as either a current or non-current asset or liability, depending on the derivative position and the expected timing of settlement. We report these amounts on a gross basis. The Company’s derivative instruments were not designated as hedges for accounting purposes for any of the periods presented. Accordingly, the changes in fair value are recognized in the consolidated statements of operations in the period of change. Gains and losses on derivatives are included in cash flows from operating activities.
Fair Value Measurements	'
	Fair Value Measurements
	We measure fair value of our financial and non-financial assets and liabilities on a recurring basis. Accounting standards define fair value, establish a framework for measuring fair value and require certain disclosures about fair value measurements for assets and liabilities measured on a recurring basis. All of our derivative instruments are recorded at fair value in our financial statements. Fair value is the exit price that we would receive to sell an asset or pay to transfer a liability in an orderly transaction between market participants at the measurement date.
	The following hierarchy prioritizes the inputs used to measure fair value:
	•	Level 1 - Measurements are based on quoted prices in active markets that are unadjusted and accessible at the measurement date for identical, unrestricted assets or liabilities;
	•	Level 2 - Measurements are based on significant observable pricing inputs other than quoted prices included in Level 1 that are either directly or indirectly observable as of measurement date; or
	•	Level 3 - Measurements are based on process or valuation models that use inputs that are both significant to the fair value measurement and less observable from objective sources (i.e., supported by little or no market activity). These inputs generally reflect management’s own assumptions about the assumptions a market participant would use in pricing the asset or liability.
	Valuation techniques that maximize the use of observable inputs are favored. Assets and liabilities are classified in their entirety based on the lowest priority level of input that is significant to the fair value measurement. The assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the placement of assets and liabilities within the levels of the fair value hierarchy. 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.
Stock-Based Compensation	'
	Stock-Based Compensation
	We grant various types of stock-based awards including stock options, restricted stock units, and performance-based awards. Stock-based compensation awards granted are valued on the date of grant and are expensed, net of estimated forfeitures, over the requisite service period.
Income Taxes	'
	Income Taxes
	Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date or the date of change in estimate for income taxes.
	We routinely assess the realizability of our deferred tax assets. If we conclude that it is more likely than not that some or all of the deferred tax assets will not be realized, the tax asset is reduced by a valuation allowance. Numerous judgments and assumptions are inherent in the determination of future taxable income, including factors such as future operating conditions (particularly as related to prevailing oil and gas prices) and changing tax laws.
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 consolidated balance sheets.
Guarantees	'
	Guarantees
	On July 12, 2012, we signed a direct guarantee for 55% of the loan obligations outstanding of $5,074 with FSG Bank for the Pellissippi Pointe equity investment. The Company's guarantee is included within the scope of ASC 460, "Guarantees" and a liability was recorded at the estimated fair value of $250; such amount is included in accrued expenses on our consolidated balance sheet as of April 30, 2013 and April 30, 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 April 30, 2014, our maximum potential undiscounted payment under this arrangement is $2,791 plus additional lender's costs.
Income (Loss) Per Share	'
	Income (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).
Business Combinations	'
	Business Combinations
	We account for business combinations under the acquisition method of accounting. The acquisition method requires that the acquired assets and liabilities, including contingencies, be recorded at fair value determined on the acquisition date and that changes thereafter be reflected in income (loss). The estimation of the fair values of the assets acquired and liabilities assumed involves a number of estimates and assumptions that could differ materially from the actual amounts recorded. The results of the acquired businesses are included in our results from operations beginning from the day of acquisition.
Statement of Comprehensive Income	'
	Statement of Comprehensive Income
	No statement of comprehensive income is presented since net income (loss) and comprehensive income (loss) would be the same for all periods reported.
New Accounting Pronouncements Issued But Not Yet Adopted	'
	New Accounting Pronouncements Issued But Not Yet Adopted
	In July 2013, the FASB issued ASU 2013-11, "Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists." The amendments in ASU 2013-11 require an entity to present an unrecognized tax benefit in the financial statements as a reduction to a deferred tax asset for a net operating loss ("NOL") carryforward, a similar tax loss, or a tax credit carryforward except when: (1) a NOL carryforward, a similar tax loss, or a tax credit carryforward is not available as of the reporting date under the governing tax law to settle taxes that would result from the disallowance of the tax position; or (2) the entity does not intend to use the deferred tax asset for this purpose (provided that the tax law permits a choice). If either of these conditions exists, an entity should present an unrecognized tax benefit in the financial statements as a liability and should not net the unrecognized tax benefit with a deferred tax asset. The amendment does not affect the recognition or measurement of uncertain tax positions under ASC Topic 740, "Income Taxes". The amendments in this ASU are effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. The amendments should be applied prospectively to all unrecognized tax benefits that exist at the effective date. Retrospective application is permitted. We do not expect this ASU to have a material impact to our consolidated financial statements.
	In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606)” (“ASU 2014-09”). ASU 2014-09 is intended to improve the financial reporting requirements for revenue from contracts with customers by providing a principle based approach. The core principal of the standard is that revenue should be recognized when the transfer of promised goods or services is made in an amount that the entity expects to be entitled to in exchange for the transfer of goods and services. ASU 2014-09 also requires disclosures enabling users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. This standard will be effective for financial statements issued by public companies for annual reporting periods beginning after December 15, 2016. Early adoption is not permitted. The Company is currently evaluating the potential impact of ASU 2014-09 on the 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.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Apr. 30, 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 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

Derivative_Instruments_Tables

Derivative Instruments (Tables)	12 Months Ended
	Apr. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of Derivative Instruments	'
	As of April 30, 2014, we had the following open crude oil derivative positions. All are priced based on the ICE Brent crude oil futures as traded on the New York Mercantile Exchange.
			Fixed - Price Swaps
	Production Period ending April 30,		Bbls			Weighted Average Fixed Price
	2015		785,000			$	100.75
	2016		787,600			$	95.66
	2017		232,600			$	94.27
Schedule of Derivative Liabilities at Fair Value	'
	The following table presents the fair value of commodity derivatives. The fair value amounts are presented on a gross basis and do not reflect the netting of asset and liability positions permitted under the terms of our master netting arrangements.
			Asset Derivatives										Liability Derivatives
			April 30, 2014						April 30, 2013				April 30, 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		$	88			Prepaid expenses and other		$	—	Current portion of derivative instruments	$	(3,315	)	Current portion of derivative instruments	$	(842	)
	Commodity derivatives		Other assets		26				Other assets		—		Long-term portion of derivative instruments	(4,006		)	Long-term portion of derivative instruments	—
	Total derivatives not designated as hedging instruments under ASC 815				$	114					$	—		$	(7,321	)		$	(842	)
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	'
	The following table presents our gross and net derivative assets and liabilities:
		Gross Amount Presented on Balance Sheet				Netting Adjustments (a)				Net Amount
	April 30, 2014
	Derivative assets with right of offset or master netting agreements	$	114			$	(114	)		$	—
	Derivative liabilities with right of offset or master netting agreements	$	(7,321	)		$	114			$	(7,207	)
	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 consolidated statements of operations. The following represents the Company’s reported gains and losses on derivative instruments for the years presented:
		For the Year Ended April 30,
		2014				2013				2012
	Gain (loss) on derivatives, net	$	(10,179	)		$	6,751			$	(2,832	)

Acquisitions_Tables

Acquisitions (Tables)	12 Months Ended
	Apr. 30, 2014
Business Combinations [Abstract]	'
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	'
	The following table summarizes the consideration paid for the North Fork Properties and the preliminary allocation of the purchase price to the assets acquired and liabilities assumed that have been included in the Company's consolidated financial statements for periods subsequent to the acquisition date.
	Accounts receivable	$	49
	Proved oil and gas properties	55,454
	Unproved oil and gas properties	5,958
	Accounts payable	(433		)
	Asset retirement obligation	(1,437		)
	Long-term liabilities	(34		)
	Consideration paid	$	59,557

Debt_Tables

Debt (Tables)	12 Months Ended
	Apr. 30, 2014
Debt Disclosure [Abstract]	'
Schedule of Long-term Debt Instruments	'
	As of April 30, 2014 and 2013, we had the following debt obligations reflected at their respective carrying values on our consolidated balance sheets:
		As of April 30,
		2014			2013
	Second Lien Credit Facility	$	175,000		$	—
	Debt discount related to Second Lien Credit Facility	(3,296		)	—
	Gunsight Promissory Note payable	950			—
	Apollo prepayment and extension fee note payable	9,223			—
	Apollo senior secured Credit Facility	—			55,307
	Debt discount related to Apollo senior secured Credit Facility	—			(2,581		)
	Series B Preferred Stock	2,325			2,252
	Total debt obligations	184,202			54,978
	Less: Current maturities	(9,459		)	(6,000		)
	Total debt less current maturities	$	174,743		$	48,978

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	12 Months Ended
	Apr. 30, 2014
Asset Retirement Obligation Disclosure [Abstract]	'
Schedule of Asset Retirement Obligations	'
	The following table presents changes to the Company's asset retirement obligation liability for the years ended April 30, 2014 and 2013:
		2014			2013
	Asset retirement obligation, beginning of year	$	19,890		$	18,366
	Additions	1,744			64
	Accretion expense	1,239			900
	Settlements	(36		)	—
	Revisions	35			560
	Asset retirement obligation, end of year	$	22,872		$	19,890

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Apr. 30, 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 April 30, 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

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Apr. 30, 2014
Income Tax Disclosure [Abstract]	'
Schedule of Components of Income Tax Expense (Benefit)	'
	The components of income tax benefit are as follows:
		For the Year Ended April 30,
		2014				2013				2012
	Federal:
	Current	$	—			$	—			$	—
	Deferred	(14,132		)		(10,023		)		(10,168		)
	Total	(14,132		)		(10,023		)		(10,168		)
	State:
	Current	18				6				—
	Deferred	(772		)		234				(838		)
	Total	(754		)		240				(838		)
	Total income tax benefit	$	(14,886	)		$	(9,783	)		$	(11,006	)
Schedule of Effective Income Tax Rate Reconciliation	'
	A reconciliation of the provision for income taxes as reported and the amount computed by multiplying income before taxes by the U.S. federal statutory rate of 35% is as follows:
		For the Year Ended April 30,
		2014			2013			2012
	Provision calculated at federal statutory rate	(35.0	)%		(35.0	)%		(35.0	)%
	State and local income taxes, net of federal benefit	(8.4	)		(8.4	)		(7.8	)
	Change in effective state tax rate	(1.5	)		9.3			5
	State valuation allowance	8.1			—			—
	Other	2.5			1.7			0.7
	Total income tax benefit	(34.3	)%		(32.4	)%		(37.1	)%
Schedule of Deferred Tax Assets and Liabilities	'
	Significant components of the Company's deferred tax assets (liabilities) consist of the following:
		April 30,
		2014				2013
	Deferred tax assets:
	Unrealized derivative loss	$	2,995			$	397
	Apollo prepayment penalty	3,832				—
	Net operating loss carryforwards	36,542				31,136
	Stock options and warrants	12,865				11,384
	Other	3,055				2,126
	Total deferred tax assets	59,289				45,043
	Valuation allowance	(3,527		)		—
	Total deferred tax assets, net of valuation allowance	55,762				45,043
	Deferred tax liabilities:
	Excess of book basis over tax basis of oil and gas properties and equipment	(191,389		)		(200,912		)
	Alaska carried-forward annual loss credits	(6,845		)		(1,401		)
	Other	(154		)		(260		)
	Total deferred tax liabilities	(198,388		)		(202,573		)
	Net deferred tax liability	$	(142,626	)		$	(157,530	)

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Apr. 30, 2014
Share-based Compensation [Abstract]	'
Schedule of Share-based Payment Award, Options and Warrants, Valuation Assumptions	'
	We estimated the grant date fair value of employee stock options and warrants using the Black-Scholes pricing model with the following weighted average assumptions:
		2014		2013		2012
	Risk-free interest rate	1.90%		0.80%		1.40%
	Term (in years)	5.8		5.8		4.7
	Volatility	70%		83%		83%
	Dividend yield	—%		—%		—%
Schedule of Share-based Payment Award, Nonemployee Stock Awards, Valuation Assumptions	'
	We estimated the grant date fair value of non-employee stock awards issued for services using the Black-Scholes pricing model with the following weighted average assumptions:
		2014		2013		2012
	Risk-free interest rate	1.80%		0.60%		1.80%
	Term (in years)	5.8		4.9		5
	Volatility	70%		79%		86%
	Dividend yield	—%		—%		—%
Schedule of Share-based Compensation, Activity	'
	The following table summarizes our stock-based compensation activities for the years ended April 30, 2014, 2013 and 2012:
		2014						2013					2012
		Number of Options and Warrants			Weighted Average Exercise Price			Number of Options and Warrants		Weighted Average Exercise Price			Number of Options and Warrants		Weighted Average Exercise Price
	Balance at beginning of year	14,403,847			$	4.61		15,405,955		$	4.6		11,079,955		$	3.98
	Granted	2,357,500			5.7			966,750		4.34			5,345,000		5.34
	Exercised	(1,681,654	)		2.76			(1,286,001	)	2.98			(969,000	)	1.43
	Canceled	(58,346	)		4.27			(682,857	)	5.33			(50,000	)	5.94
	Balance at end of year	15,021,347			4.99			14,403,847		4.61			15,405,955		4.6
	Options exercisable at April 30	10,621,164			$	4.73		9,821,403		$	4.25		8,268,459		$	3.78
Schedule of Share-based Compensation, Shares and Warrants Authorized under Stock Option Plans, by Exercise Price Range	'
	The following table summarizes our stock options and warrants outstanding, including exercisable shares at April 30, 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		1,506,400			1.2	$	0.7		1,506,400		$	0.7
	$2.00 to $4.99		1,783,000			5.4	3.55			1,391,154		3.39
	$5.25 to $5.53		4,491,947			3.4	5.32			2,636,947		5.32
	$5.89 to $5.94		3,295,000			6.4	5.92			2,936,663		5.93
	$6.00 to $6.95		3,945,000			3.6	6.13			2,150,000		6.08
			15,021,347			4.1	$	4.99		10,621,164		$	4.73
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	'
	The following table summarizes restricted stock activity for the years ended April 30, 2014, 2013 and 2012:
		2014			2013		2012
	Unvested at beginning of year	591,030			147,000		97,000
	Granted	520,000			997,172		130,000
	Vested	(630,348	)		(536,142	)	(75,000	)
	Forfeited	(15,250	)		(17,000	)	(5,000	)
	Unvested at end of year	465,432			591,030		147,000

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Apr. 30, 2014
Fair Value Disclosures [Abstract]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	'
	The following summarizes the fair value of the Company’s commodity derivative assets and liabilities according to their fair value hierarchy as of the reporting dates indicated:
		Fair Value Measurements
	At April 30, 2014	Level 1		Level 2			Level 3
	Commodity derivative asset	$	—	$	114		$	—
	Commodity derivative liability	—		(7,321		)	—
	Total	$	—	$	(7,207	)	$	—
	At April 30, 2013
	Commodity derivative asset	$	—	$	—		$	—
	Commodity derivative liability	—		(842		)	—
	Total	$	—	$	(842	)	$	—

Oil_and_Gas_Properties_and_Equ1

Oil and Gas Properties and Equipment (Tables)	12 Months Ended
	Apr. 30, 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:
		April 30,
		2014			2013
	Property costs
	Proved property	$	467,740		$	332,241
	Unproved property	243,107			196,500
	Total property costs	710,847			528,741
	Less: Accumulated depletion	(66,020		)	(37,427		)
	Oil and gas properties, net	$	644,827		$	491,314
	Capitalized Costs Relating to Oil and Gas Producing Activities at April 30, 2014, 2013 and 2012 are as follows:
		2014			2013			2012
	Natural gas and oil properties:
	Proved properties	$	467,740		$	332,241		$	321,066
	Unproved properties	243,107			196,500			182,704
		710,847			528,741			503,770
	Accumulated depletion	(66,020		)	(37,427		)	(27,968		)
	Net capitalized costs	$	644,827		$	491,314		$	475,802
Property, Plant and Equipment	'
	Equipment is summarized as follows:
		April 30,
		2014			2013
	Machinery and equipment	$	7,759		$	7,413
	Vehicles	1,877			1,851
	Aircraft	—			476
	Buildings	2,726			2,725
	Office equipment	1,108			759
	Leasehold improvements	527			482
	Drilling rigs	30,210			30,117
	Payment on drilling rig	1,500			—
		45,707			43,823
	Less: Accumulated depreciation	(10,338		)	(6,252		)
	Equipment, net	$	35,369		$	37,571
Depreciation, Depletion and Amortization	'
	Depreciation, depletion and amortization consisted of the following:
		For the Year Ended April 30,
		2014			2013			2012
	Depletion of oil and gas related assets	$	29,292		$	9,803		$	12,537
	Depreciation and amortization of equipment	4,236			3,367			773
	Total	$	33,528		$	13,170		$	13,310

Alaska_Production_Credits_Tabl

Alaska Production Credits (Tables)	12 Months Ended
	Apr. 30, 2014
Alaska Production Credits [Abstract]	'
Allowance for Credit Losses on Financing Receivables	'
	We did not incur any Alaska production taxes in fiscal 2014, 2013 or 2012, and accordingly, the carried-forward annual loss credits are presented separately in our operating expenses on the consolidated statement of operations.
	Balance, April 30, 2013	$	12,713
	Applications for carried-forward annual loss credits1	16,342
	Applications for expenditure and exploration based credits1	41,841
	Cash collections for carried-forward annual loss credits	(3,244		)
	Cash collections for expenditure and exploration based credits	(18,531		)
	Balance, April 30, 2014	$	49,121
	————————
	1	Applications for carried-forward annual loss credits for expenditure and exploration based credits are recorded net of established reserves and also include revisions to prior period applications, if applicable.

Subsequent_Events_Tables

Subsequent Events (Tables)	12 Months Ended
	Apr. 30, 2014
Subsequent Events [Abstract]	'
Schedule of Line of Credit Facilities Borrowing Base Utilization	'
	The First Lien Loan Agreement provides for a $250,000 senior secured, reserve-based revolving credit facility, $60,000 of which was made available to us on the closing date. Amounts outstanding under the First Lien RBL are priced on a sliding scale, based on LIBOR plus 300 to 400 basis points and an undrawn commitment fee, depending upon the level of borrowing (per the table below).
	Borrowing Base Utilization Grid
	Borrowing base utilization percentage	<25%	≥ 25%, but <50%	≥ 50%, but <75%	≥ 75%, but <90%	≥ 90%, but ≤100%
	Spread above LIBOR	3.00%	3.25%	3.50%	3.75%	4.00%
	Undrawn commitment fee rate	0.50%	0.50%	0.75%	0.75%	0.75%

Supplemental_Oil_and_Gas_Discl1

Supplemental Oil and Gas Disclosures (Unaudited) (Tables)	12 Months Ended
	Apr. 30, 2014
Oil and Gas Exploration and Production Industries Disclosures [Abstract]	'
Capitalized Costs Relating to Oil and Gas Producing Activities Disclosure	'
	Oil and gas properties (successful efforts method) are summarized as follows:
		April 30,
		2014				2013
	Property costs
	Proved property	$	467,740			$	332,241
	Unproved property	243,107				196,500
	Total property costs	710,847				528,741
	Less: Accumulated depletion	(66,020		)		(37,427		)
	Oil and gas properties, net	$	644,827			$	491,314
	Capitalized Costs Relating to Oil and Gas Producing Activities at April 30, 2014, 2013 and 2012 are as follows:
		2014				2013				2012
	Natural gas and oil properties:
	Proved properties	$	467,740			$	332,241			$	321,066
	Unproved properties	243,107				196,500				182,704
		710,847				528,741				503,770
	Accumulated depletion	(66,020		)		(37,427		)		(27,968		)
	Net capitalized costs	$	644,827			$	491,314			$	475,802
Cost Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities Disclosure	'
	Costs Incurred in Oil and Gas Property Acquisition, Exploration, and Development Activities:
		2014				2013				2012
	Property acquisition costs
	Proved properties	$	54,535			$	689			$	—
	Unproved properties	7,564				704				785
	Acquisition costs	62,099				1,393				785
	Exploration costs	1,713				1,268				180
	Development costs	133,778				24,968				6,773
	Total	$	197,590			$	27,629			$	7,738
Results of Operations for Oil and Gas Producing Activities Disclosure	'
	Results of Operations for Producing Activities:
		2014				2013				2012
	Production revenues	$	69,469			$	29,915			$	32,493
	Lease operating expense	(20,187		)		(22,288		)		(11,305		)
	Transportation costs	(5,599		)		(2,410		)		(3,556		)
	Alaska carried-forward annual loss credits, net	16,342				3,268				—
	Depletion	(35,212		)		(13,041		)		(13,094		)
	Results of operations for producing activities (excluding corporate overhead and interest costs)	$	24,813			$	(4,556	)		$	4,538
Schedule of Proved Developed and Undeveloped Oil and Gas Reserve Quantities	'
	The following schedule estimates proved oil and natural gas reserves attributable to the Company. Proved reserves are estimated quantities of oil and natural gas which geological and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions. Proved developed reserves are those which are expected to be recovered through existing wells with existing equipment and operating methods. Reserves are stated in barrels of oil (Bbls) and thousands of cubic feet of natural gas (Mcf). Geological and engineering estimates of proved oil and natural gas reserves at one point in time are highly interpretive, inherently imprecise and subject to ongoing revisions that may be substantial in amount. Although every reasonable effort is made to ensure that the reserve estimates reported represent the most accurate assessments possible, these estimates are by their nature generally less precise than other estimates presented in connection with financial statement disclosures.
		Oil (MBbls)			Gas (MMcf)			MBoe
	Proved reserves
	Balance, April 30, 2011	8,948			3,243			9,489
	Extensions, discoveries and other additions	94			1,850			402
	Revisions of previous estimates	(124	)		(359	)		(183	)
	Acquisition of reserves in place	—			—			—
	Production	(384	)		(177	)		(414	)
	Balance, April 30, 2012	8,534			4,557			9,294
	Extensions, discoveries and other additions	26			35			32
	Revisions of previous estimates	(317	)		(519	)		(404	)
	Acquisition of reserves in place	6			—			6
	Production	(295	)		(133	)		(317	)
	Balance, April 30, 2013	7,954			3,940			8,611
	Extensions, discoveries and other additions	2,113			—			2,113
	Revisions of previous estimates	(3,286	)		(231	)		(3,325	)
	Acquisition of reserves in place	—			24,726			4,121
	Production	(685	)		(794	)		(817	)
	Balance, April 30, 2014	6,096			27,641			10,703
	Proved developed reserves at April 30, 2012	2,325			2,601			2,759
	Proved developed reserves at April 30, 2013	1,697			513			1,783
	Proved developed reserves at April 30, 2014	4,264			12,202			6,298
	Proved undeveloped reserves at April 30, 2012	6,209			1,956			6,535
	Proved undeveloped reserves at April 30, 2013	6,257			3,427			6,828
	Proved undeveloped reserves at April 30, 2014	1,832			15,439			4,405
Standardized Measure of Discounted Future Cash Flows Relating to Proved Reserves Disclosure	'
	Standardized measures of discounted future net cash flows at April 30, 2014, 2013 and 2012 are as follows:
		2014				2013				2012
	Future cash flows	$	810,184			$	801,134			$	894,027
	Future production costs and taxes	(218,407		)		(178,779		)		(158,938		)
	Future development costs	(90,812		)		(72,434		)		(75,332		)
	Future income tax expense	(117,263		)		(150,568		)		(217,312		)
	Future cash flows	383,702				399,353				442,445
	Discount at 10% for timing of cash flows	(99,574		)		(124,905		)		(139,242		)
	Discounted future net cash flows from proved reserves	$	284,128			$	274,448			$	303,203
Schedule of Changes in Standardized Measure of Discounted Future Net Cash Flows	'
	The following table sets forth the changes in the standardized measure of discounted future net cash flows from proved reserves for April 30, 2014, 2013 and 2012.
		April 30,
		2014				2013				2012
	Balance, beginning of year	$	274,448			$	303,203			$	206,801
	Sales, net of production costs and taxes	(43,683		)		(5,217		)		(17,632		)
	Changes in prices and production costs	(45,258		)		(59,253		)		116,689
	Extensions, discoveries and other additions	100,868				1,302				58,906
	Acquisition of reserves in place	73,946				295				—
	Changes in estimated future development costs	11,744				(2,856		)		7,641
	Development costs incurred	10,131				5,522				6,773
	Revisions of previous quantity estimates	(143,565		)		(21,828		)		(42,857		)
	Net changes in income taxes	15,502				49,486				(48,571		)
	Sales of reserves in place	—				—				—
	Accretion of discount	37,176				39,472				30,503
	Changes in timing and other	(7,181		)		(35,678		)		(15,050		)
	Balance, end of year	$	284,128			$	274,448			$	303,203

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details) (USD $)	Apr. 30, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Oil and gas properties, net	$644,827	$491,314
Equipment, net	35,369	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

Summary_of_Significant_Account4

Summary of Significant Accounting Policies (Details 1) (USD $)	Apr. 30, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Deferred financing costs, net	$803	$2,085
Long-term debt, less current portion	174,743	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

Summary_of_Significant_Account5

Summary of Significant Accounting Policies (Details Textual) (USD $)	0 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Jul. 12, 2012	Jun. 24, 2011	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Reclassifications	'	'	'	'	'
Reclassification adjustment	'	'	'	$5,305	'
Restricted Cash	'	'	'	'	'
Cash controlled by lender	'	'	38	7,144	'
Accounts Receivable and Allowance for Doubtful Accounts	'	'	'	'	'
Established reserve	'	'	250	'	'
Oil and Gas Property	'	'	'	'	'
Lease abandonment	'	'	296	'	'
Seismic and delay rental incurred	'	'	1,695	'	'
Delay rental incurred	'	'	19	'	'
Capitalized Interest	'	'	'	'	'
Interest expense	'	'	14,433	9,289	5,500
Capitalized costs in equipment and oil and gas properties	'	'	8,569	5,880	3,700
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	'	'

Derivative_Instruments_Details

Derivative Instruments (Details) (Not Designated as Hedging Instrument [Member], Crude Oil [Member], Swap [Member])	12 Months Ended
	Apr. 30, 2014
	bbl
2015 [Member]	'
Derivative [Line Items]	'
Open positions (in barrels)	785,000
Weighted average fixed price (in dollars per barrel)	100.75
2016 [Member]	'
Derivative [Line Items]	'
Open positions (in barrels)	787,600
Weighted average fixed price (in dollars per barrel)	95.66
2017 [Member]	'
Derivative [Line Items]	'
Open positions (in barrels)	232,600
Weighted average fixed price (in dollars per barrel)	94.27

Derivative_Instruments_Details1

Derivative Instruments (Details 1) (Commodity Contract [Member], Not Designated as Hedging Instrument [Member], USD $)	Apr. 30, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Commodity derivative asset	$114	$0
Commodity derivative liability	-7,321	-842
Prepaid Expenses and Other Current Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Commodity derivative asset	88	'
Other Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Commodity derivative asset	26	'
Current Portion of Derivative Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Commodity derivative liability	-3,315	-842
Long-term Portion of Derivative Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Commodity derivative liability	($4,006)	'

Derivative_Instruments_Details2

Derivative Instruments (Details 2) (Not Designated as Hedging Instrument [Member], Commodity Contract [Member], USD $)	Apr. 30, 2014		Apr. 30, 2013
In Thousands, unless otherwise specified
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member]	'		'
Derivatives, Fair Value [Line Items]	'		'
Gross derivative assets presented on balance sheet	$114		$0
Netting adjustments	-114	[1]	0	[1]
Net derivative assets	0		0
Gross derivative liabilities presented on balance sheet	-7,321		-842
Netting adjustments	114	[1]	0	[1]
Net derivative liabilities	($7,207)		($842)
[1]	(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_Instruments_Details3

Derivative Instruments (Details 3) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'	'	'
Gain (loss) on derivatives, net	($10,179)	$6,751	($2,832)

Derivative_Instruments_Details4

Derivative Instruments (Details Textual) (USD $)	Sep. 18, 2013	Jul. 08, 2013	Jan. 08, 2013	Jul. 11, 2012	20-May-11	Jun. 29, 2012	Apr. 30, 2012	Mar. 26, 2010	Sep. 21, 2012
In Thousands, except Share data, unless otherwise specified						Series A Preferred Stock [Member]	Series A Preferred Stock [Member]	Other Equity Transactions [Member]	Special Warrant Exercise Agreement [Member]
Derivative Instruments	'	'	'	'	'	'	'	'	'
Warrants issued (in shares)	150,000	12,500	12,500	150,000	300,000	'	1,000,000	817,055	'
Exercise price (in dollars per share)	6.63	4.15	3.56	5.28	5.51	'	5.28	5.28	4
Adjusted exercise price (in dollars per share)	'	'	'	'	'	3	'	'	'
Gain (loss) on derivatives, net	'	'	'	'	'	$443	'	'	$260
Additional paid-in capital	'	'	'	'	'	2,510	'	'	1,840
Warrants exercised (in shares)	300,000	'	'	'	'	'	'	'	586,001
Warrants cancelled (in shares)	'	'	'	'	'	'	'	'	42,857
Settlement payment	'	'	'	'	'	'	'	'	75
Loss on warrant modification	'	'	'	'	'	'	'	'	$210
Warrants outstanding (in shares)	'	'	'	'	'	'	'	'	138,197

Acquisitions_Details

Acquisitions (Details) (USD $)	Apr. 30, 2014
In Thousands, unless otherwise specified
Business Combinations [Abstract]	'
Accounts receivable	$49
Proved oil and gas properties	55,454
Unproved oil and gas properties	5,958
Accounts payable	-433
Asset retirement obligation	-1,437
Long-term liabilities	-34
Consideration paid	$59,557

Acquisitions_Details_Textual

Acquisitions (Details Textual) (USD $)	0 Months Ended		12 Months Ended			0 Months Ended
In Thousands, except Share data, unless otherwise specified	Feb. 03, 2014	Nov. 22, 2013	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012	Jan. 31, 2014	Apr. 30, 2014	Sep. 30, 2013
		Well				Series D Preferred Stock [Member]	Series D Preferred Stock [Member]	Series D Preferred Stock [Member]
		acre
Business Acquisition [Line Items]	'	'	'	'	'	'	'	'
Working interest acquired (percent)	'	100.00%	'	'	'	'	'	'
Number of gas wells acquired	'	6	'	'	'	'	'	'
Area acquired (in acres)	'	15,465	'	'	'	'	'	'
Total cash consideration paid	'	$59,557	'	'	'	'	'	'
Shares issued (in shares)	'	'	'	'	'	213,586	1,070,448	1,000,000
Preferred stock issued for acquisition	'	'	'	'	'	5,000	'	'
Financed acquisition cost	56,577	'	'	'	'	'	'	'
Cash deposit on acquisition	'	3,000	500	'	'	'	'	'
Acquisition-related costs	'	'	404	'	'	'	'	'
Net revenue included	'	'	$4,124	'	'	'	'	'

Debt_Details

Debt (Details) (USD $)	Apr. 30, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Long-term Debt, Excluding Current Maturities [Abstract]	'	'
Gunsight Promissory Note payable	$950	'
Series B Preferred Stock	2,325	2,252
Total debt obligations	184,202	54,978
Less: Current maturities	-9,459	-6,000
Total debt less current maturities	174,743	48,978
Second Lien Credit Facility [Member]	'	'
Long-term Debt, Excluding Current Maturities [Abstract]	'	'
Credit facility amount	175,000	'
Debt discount	-3,296	'
Apollo Senior Secured Credit Facility [Member]	'	'
Long-term Debt, Excluding Current Maturities [Abstract]	'	'
Credit facility amount	'	55,307
Debt discount	'	-2,581
Prepayment and extension fee note payable	$9,223	'

Debt_Details_Textual

Debt (Details Textual) (USD $)

0 Months Ended

12 Months Ended

0 Months Ended

0 Months Ended

9 Months Ended

12 Months Ended

0 Months Ended

Feb. 03, 2014

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2012

Feb. 03, 2014

Apr. 30, 2014

Feb. 03, 2014

Aug. 05, 2013

Apr. 25, 2013

Feb. 07, 2013

Jun. 29, 2012

Feb. 03, 2014

Apr. 30, 2013

Jun. 29, 2012

Jun. 29, 2012

Second Lien Credit Facility [Member]

Second Lien Credit Facility [Member]

Second Lien Credit Facility [Member]

Apollo Senior Secured Credit Facility [Member]

Apollo Senior Secured Credit Facility [Member]

Apollo Senior Secured Credit Facility [Member]

Apollo Senior Secured Credit Facility [Member]

Apollo Senior Secured Credit Facility [Member]

Apollo Senior Secured Credit Facility [Member]

Apollo Senior Secured Credit Facility [Member]

Apollo Senior Secured Credit Facility [Member]

London Interbank Offered Rate (LIBOR) [Member]

Line of Credit [Member]

Accounts Payable [Member]

Line of Credit Facility [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility

'

'

'

'

$175,000,000

'

'

'

'

'

$100,000,000

'

'

'

'

Original issue discount (percent)

'

'

'

'

2.00%

'

'

'

'

'

'

'

'

'

'

Variable rate (percent)

'

'

'

'

'

'

9.75%

'

'

'

'

'

'

'

'

LIBOR floor rate (percent)

'

'

'

'

'

'

2.00%

'

'

'

'

'

'

'

'

Maturity (in years)

'

'

'

'

'4 years

'

'

'

'

'

'

'

'

'

'

Refinance of credit facility

'

'

'

'

75,306,000

'

'

'

'

'

'

'

'

'

'

Financed acquisition cost

56,577,000

'

'

'

56,577,000

'

'

'

'

'

'

'

'

'

'

Repayment of notes payable obligation

'

3,071,000

'

'

3,071,000

'

'

'

'

'

'

'

'

'

'

Fair value of outstanding balance

'

'

'

'

'

176,785,000

'

'

'

'

'

'

'

'

'

Borrowing base

175,000,000

'

'

'

'

'

'

75,000,000

'

'

55,000,000

'

'

'

'

Amount borrowed

175,000,000

'

'

'

'

'

'

20,000,000

10,000,000

5,000,000

40,000,000

'

'

'

'

Increase in borrowing capacity

'

'

'

'

'

'

'

20,000,000

'

'

'

'

'

'

'

Interest rate per annum (percent)

'

'

'

'

'

'

'

18.00%

'

'

'

'

'

'

'

Maximum periodic principal payment

'

'

'

'

'

'

'

'

'

'

'

1,500,000

'

'

'

Payment-in-kind interest on debt

'

'

307,000

'

'

'

'

'

'

'

'

'

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 (percent)

'

'

'

'

'

'

'

9.00%

'

'

'

'

'

'

'

Unamortized deferred financing costs

'

$803,000

$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				12 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 03, 2014	Sep. 03, 2013	Mar. 01, 2013	Sep. 24, 2012	Apr. 30, 2014
				Investors
Cumulative Preferred Stock Subject to Mandatory Redemption [Member] | Series B Preferred Stock [Member]	'	'	'	'	'
Preferred Stock	'	'	'	'	'
Shares issued (in shares)	'	'	'	25,750	'
Number of investors	'	'	'	10	'
Common stock for purchase (in shares)	'	'	'	128,750	'
Gross proceeds	'	'	'	$2,575	'
Issuance costs	'	'	'	167	'
Fair value	'	'	'	'	$2,197
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)	$5.95	$6.05	$5.16	'	'

Debt_Details_Textual_2

Debt (Details Textual 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Feb. 03, 2014	Apr. 30, 2013
Debt Disclosure [Abstract]	'	'	'
Obligations of note payable repaid (percent)	'	100.00%	'
Gunsight Promissory Note payable	$950	'	'
Interest rate per annum (percent)	5.00%	'	'

Debt_Details_Textual_3

Debt (Details Textual 3) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Line of Credit Facility [Line Items]	'	'	'	'
Debt extinguishment	$15,145	$15,145	'	'
Other charges	5,185	'	'	'
Termination and repayment fee	737	'	'	'
Apollo Senior Secured Credit Facility [Member]	'	'	'	'
Line of Credit Facility [Line Items]	'	'	'	'
Prepayment and extension fee note payable	9,223	9,223	'	'
Number of prepayment fee installments	4	4	'	'
Amount payable per installment	$2,306	'	'	'

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]	'	'	'
Asset retirement obligation, beginning of year	$19,890	$18,366	'
Additions	1,744	64	'
Accretion expense	1,239	900	1,072
Settlements	-36	'	'
Revisions	35	560	'
Asset retirement obligation, end of year	$22,872	$19,890	$18,366

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	Apr. 30, 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 $)	12 Months Ended
	Apr. 30, 2014	Mar. 11, 2011
Long-term Purchase Commitment [Line Items]	'	'
Notification deadline (in days)	'10 days	'
Project, item or purchase price	$5,000,000	'
Bond amount	'	18,000,000
Funding obligations	11,000,000	12,000,000
Funded obligations	1,000,000	'
WMRU [Member]	'	'
Long-term Purchase Commitment [Line Items]	'	'
Funding commitment	5,150,000	'
Redoubt Unit [Member]	'	'
Long-term Purchase Commitment [Line Items]	'	'
Funding commitment	$31,000,000	'

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Federal:	'	'	'
Current	'	'	'
Deferred	-14,132	-10,023	-10,168
Total	-14,132	-10,023	-10,168
State:	'	'	'
Current	18	6	'
Deferred	-772	234	-838
Total	-754	240	-838
Total income tax benefit	($14,886)	($9,783)	($11,006)

Income_Taxes_Details_1

Income Taxes (Details 1)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]	'	'	'
Provision calculated at federal statutory rate (percent)	-35.00%	-35.00%	-35.00%
State and local income taxes, net of federal benefit (percent)	-8.40%	-8.40%	-7.80%
Change in effective state tax rate (percent)	-1.50%	9.30%	5.00%
State valuation allowance (percent)	8.10%	'	'
Other (percent)	2.50%	1.70%	0.70%
Total income tax benefit (percent)	-34.30%	-32.40%	-37.10%

Income_Taxes_Details_2

Income Taxes (Details 2) (USD $)	Apr. 30, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Deferred tax assets:	'	'
Unrealized derivative loss	$2,995	$397
Apollo prepayment penalty	3,832	'
Net operating loss carryforwards	36,542	31,136
Stock options and warrants	12,865	11,384
Other	3,055	2,126
Total current deferred tax assets	59,289	45,043
Valuation allowance	-3,527	0
Total deferred tax assets, net of valuation allowance	55,762	45,043
Deferred tax liabilities:	'	'
Excess of book basis over tax basis of oil and gas properties and equipment	-191,389	-200,912
Alaska state tax credit	-6,845	-1,401
Other	-154	-260
Deferred tax liabilities:	-198,388	-202,573
Net deferred tax liability	($142,626)	($157,530)

Income_Taxes_Details_Textual

Income Taxes (Details Textual) (USD $)	Apr. 30, 2014
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]	'
Operating loss carryforwards	$81,737
Valuation allowance	3,527
Amount to be recorded to APIC	175
Significant payments expected	$0

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)

0 Months Ended

12 Months Ended

In Thousands, except Share data, unless otherwise specified

Sep. 18, 2013

Jul. 08, 2013

Jan. 08, 2013

Jul. 11, 2012

Jul. 03, 2012

Jun. 29, 2012

Jan. 01, 2012

Aug. 04, 2011

20-May-11

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2012

Stockholders' Equity Note [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

Shares outstanding (in shares)

'

'

'

'

'

'

'

'

'

45,756,697

43,444,694

41,086,751

Shares issued (in shares)

'

'

'

'

'

'

'

'

'

2,312,003

2,357,943

1,356,500

Shares issued for employee compensation (in shares)

'

'

'

'

'

'

'

'

'

630,349

527,665

257,500

Exercise of equity rights (in shares)

'

'

'

'

'

'

'

'

'

1,681,654

1,286,001

96,900

Shares issued for services (in shares)

'

'

'

'

38,977

312,500

30,000

100,000

'

'

351,477

130,000

Shares issued for other equity issuances (in shares)

'

'

'

'

'

'

'

'

'

'

192,800

'

Warrants issued (in shares)

150,000

12,500

12,500

150,000

'

'

'

'

300,000

'

'

'

Exercise price (in dollars per share)

6.63

4.15

3.56

5.28

'

'

'

'

5.51

'

'

'

Term (in years)

'3 years

'

'

'

'

'

'

'

'

'

'

'

Fair value

$442

$22

$24

$406

$194

$1,563

$100

$300

$1,100

'

'

'

Risk free rate (percent)

0.70%

0.70%

0.10%

0.60%

'

'

'

'

1.80%

'

'

'

Expected volatility rate (percent)

67.00%

66.00%

75.00%

79.00%

'

'

'

'

86.00%

'

'

'

Expected term (in years)

'3 years

'3 years

'3 years 6 months

'5 years

'

'

'

'

'5 years

'

'

'

Stockholders_Equity_Details_1

Stockholders' Equity (Details 1) (USD $)

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

19 Months Ended

In Thousands, except Share data, unless otherwise specified

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2012

Apr. 16, 2014

Mar. 03, 2014

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, 2014

Apr. 30, 2013

Jun. 02, 2014

Apr. 30, 2014

Apr. 30, 2014

Apr. 30, 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]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Series C Preferred Stock [Member]

Subsequent Event [Member]

Series C ATM Agreement [Member]

Series C ATM Agreement [Member]

Series C ATM Agreement [Member]

Minimum [Member]

Maximum [Member]

Class of Stock [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares issued (in shares)

'

'

'

'

'

'

'

'

'

'

335,000

'

500,000

1,454,901

625,000

685,000

3,069,968

1,454,901

'

924,968

'

'

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

'

'

'

$20,935

'

'

Issuance costs

3,894

2,667

'

'

'

'

'

'

'

'

547

'

805

'

1,052

1,335

'

'

'

733

'

'

Net proceeds

'

'

'

'

'

'

'

'

'

'

6,656

'

10,320

'

13,260

14,420

'

'

'

20,202

'

'

Accretion of preferred stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,459

2,866

'

'

'

'

Fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$77,976

'

'

'

'

'

Cumulative declared dividend rate per annum (percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10.75%

'

'

'

'

'

Potential penalty rate (percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

12.75%

'

'

'

'

'

Market Trigger

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion price (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$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

'

'

'

'

'

Liquidation preference (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$25

'

'

'

'

'

Declared dividend (in dollars per share)

'

'

'

$0.67

'

$0.67

'

$0.67

'

$0.67

'

'

'

$0.67

'

'

'

'

'

'

'

'

Dividend paid (in dollars per share)

'

'

'

'

$0.67

'

$0.67

'

$0.67

'

'

$0.67

'

'

'

'

'

'

$0.67

'

'

'

Stockholders_Equity_Details_2

Stockholders' Equity (Details 2) (USD $)

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

6 Months Ended

In Thousands, except Share data, unless otherwise specified

Apr. 30, 2014

Apr. 30, 2013

Apr. 30, 2012

Apr. 16, 2014

Mar. 03, 2014

Jan. 31, 2014

Jan. 28, 2014

Dec. 02, 2013

Oct. 17, 2013

Sep. 30, 2013

Apr. 30, 2014

Jun. 02, 2014

Apr. 30, 2014

Apr. 30, 2014

Apr. 30, 2014

Apr. 30, 2014

Apr. 30, 2014

Apr. 30, 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]

Series D Preferred Stock [Member]

Series D Preferred Stock [Member]

Subsequent Event [Member]

Before December 1, 2018 [Member]

On or After December 1, 2018 [Member]

London Interbank Offered Rate (LIBOR) [Member]

Series D ATM Agreement [Member]

Series D ATM Agreement [Member]

Series D ATM Agreement [Member]

Minimum [Member]

Maximum [Member]

Class of Stock [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares issued (in shares)

'

'

'

'

'

213,586

'

'

'

1,000,000

1,070,448

'

'

'

'

70,448

'

'

Price per share (in dollars per share)

'

'

'

'

'

'

'

'

'

$25

'

'

'

'

'

'

$23.95

$24.38

Gross proceeds

'

'

'

'

'

'

'

'

'

$25,000

'

'

'

'

'

$1,701

'

'

Issuance costs

3,894

2,667

'

'

'

'

'

'

'

1,875

'

'

'

'

'

47

'

'

Net proceeds

'

'

'

'

'

'

'

'

'

23,125

'

'

'

'

'

1,654

'

'

Preferred stock issued for acquisition

'

'

'

'

'

5,000

'

'

'

'

'

'

'

'

'

'

'

'

Accretion of Series D Preferred Stock

'

'

'

'

'

'

'

'

'

'

262

'

'

'

'

'

'

'

Fair value

'

'

'

'

'

'

'

'

'

'

$31,330

'

'

'

'

'

'

'

Cumulative dividend rate per annum (percent)

'

'

'

'

'

'

'

'

'

'

10.50%

'

'

'

'

'

'

'

Liquidation preference (in dollars per share)

'

'

'

'

'

'

'

'

'

'

$25

'

'

'

'

'

'

'

Variable rate (percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9.07%

'

'

'

Potential increase in dividend rate (percent)

'

'

'

'

'

'

'

'

'

'

2.00%

'

'

'

'

'

'

'

Potential penalty rate (percent)

'

'

'

'

'

'

'

'

'

'

'

'

12.50%

11.07%

'

'

'

'

Redemption price (in dollars per share)

'

'

'

'

'

'

'

'

'

'

$25

'

'

'

'

'

'

'

Declared dividend (in dollars per share)

'

'

'

$0.66

'

'

$0.66

'

$0.44

'

'

'

'

'

'

'

'

'

Dividend paid (in dollars per share)

'

'

'

'

$0.66

'

'

$0.44

'

'

'

$0.66

'

'

'

'

'

'

StockBased_Compensation_Detail

Stock-Based Compensation (Details)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Share-based Compensation [Abstract]	'	'	'
Risk-free interest rate (percent)	1.90%	0.80%	1.40%
Term (in years)	'5 years 9 months 18 days	'5 years 9 months 18 days	'4 years 8 months 12 days
Volatility (percent)	70.00%	83.00%	83.00%
Dividend yield (percent)	'	'	'

StockBased_Compensation_Detail1

Stock-Based Compensation (Details 1)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Share-based Compensation [Abstract]	'	'	'
Risk-free interest rate (percent)	1.80%	0.60%	1.80%
Term (in years)	'5 years 9 months 18 days	'4 years 10 months 24 days	'5 years
Volatility (percent)	70.00%	79.00%	86.00%
Dividend yield (percent)	'	'	'

StockBased_Compensation_Detail2

Stock-Based Compensation (Details 2) (USD $)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options and Warrants, Outstanding [Roll Forward]	'	'	'
Balance at beginning of year (in shares)	14,403,847	15,405,955	11,079,955
Balance at beginning of year, weighted average exercise price (in dollars per share)	$4.61	$4.60	$3.98
Granted (in shares)	2,357,500	966,750	5,345,000
Granted, weighted average price (in dollars per share)	$5.70	$4.34	$5.34
Exercised (in shares)	-1,681,654	-1,286,001	-969,000
Exercised, weighted average price (in dollars per share)	$2.76	$2.98	$1.43
Canceled (in shares)	-58,346	-682,857	-50,000
Canceled, weighted average price (in dollars per share)	$4.27	$5.33	$5.94
Balance at end of year (in shares)	15,021,347	14,403,847	15,405,955
Balance at end of year, weighted average exercise price (in dollars per share)	$4.99	$4.61	$4.60
Options exercisable at April 30 (in shares)	10,621,164	9,821,403	8,268,459
Options exercisable at April 30, weighted average price (in dollars per share)	$4.73	$4.25	$3.78

StockBased_Compensation_Detail3

Stock-Based Compensation (Details 3) (USD $)	12 Months Ended
	Apr. 30, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	15,021,347
Weighted average remaining contractural life (in years)	'4 years 1 month 6 days
Weighted average exercise price (in dollars per share)	$4.99
Number exercisable (in shares)	10,621,164
Weighted average exercise price (in dollars per share)	$4.73
$0.01 to $1.82 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	1,506,400
Weighted average remaining contractural life (in years)	'1 year 2 months 12 days
Weighted average exercise price (in dollars per share)	$0.70
Number exercisable (in shares)	1,506,400
Weighted average exercise price (in dollars per share)	$0.70
$2.00 to $4.99 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	1,783,000
Weighted average remaining contractural life (in years)	'5 years 4 months 24 days
Weighted average exercise price (in dollars per share)	$3.55
Number exercisable (in shares)	1,391,154
Weighted average exercise price (in dollars per share)	$3.39
$5.25 to $5.53 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	4,491,947
Weighted average remaining contractural life (in years)	'3 years 4 months 24 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 4 months 24 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 $6.95 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number outstanding (in shares)	3,945,000
Weighted average remaining contractural life (in years)	'3 years 7 months 6 days
Weighted average exercise price (in dollars per share)	$6.13
Number exercisable (in shares)	2,150,000
Weighted average exercise price (in dollars per share)	$6.08

StockBased_Compensation_Detail4

Stock-Based Compensation (Details 4) (USD $)	12 Months Ended
	Apr. 30, 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 $6.95 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise price range, lower limit (in dollars per share)	$6
Exercise price range, upper limit (in dollars per share)	$6.95

StockBased_Compensation_Detail5

Stock-Based Compensation (Details 5)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]	'	'	'
Unvested at beginning of year (in shares)	591,030	147,000	97,000
Granted (in shares)	520,000	997,172	130,000
Vested (in shares)	-630,348	-536,142	-75,000
Forfeited (in shares)	-15,250	-17,000	-5,000
Unvested at end of year (in shares)	465,432	591,030	147,000

StockBased_Compensation_Detail6

Stock-Based Compensation (Details Textual) (USD $)	12 Months Ended				0 Months Ended
In Thousands, except Share data, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2010	Apr. 16, 2014	Apr. 30, 2011
				2010 Stock Incentive Plan [Member]	2011 Stock Incentive Plan [Member]	2011 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'
Shares authorized (in shares)	'	'	'	3,000,000	'	8,250,000
Additional shares authorized (in shares)	'	'	'	'	5,000,000	'
Shares available for grant (in shares)	3,134,578	329,328	'	'	'	'
Employee share-based compensation expense	$4,298	$8,791	$12,545	'	'	'
Employee options and warrants, grant date fair value	5,513	1,847	13,839	'	'	'
Employee options and warrants, weighted average grant date fair value (in dollars per share)	$3.16	$2.73	$3.40	'	'	'
Nonemployee expense	1,103	2,154	1,501	'	'	'
Nonemployee stock awards, grant date fair value	1,671	431	1,119	'	'	'
Nonemployee stock awards, weighted average grant date fair value (in dollars per share)	$2.73	$2.65	$3.73	'	'	'
Aggregate intrinsic value	3,533	1,201	3,782	'	'	'
Cash received for options exercised	4,638	3,832	1,383	'	'	'
Unrecognized stock-based compensation expense	$7,931	'	'	'	'	'
Weighted average vesting term of unrecognized compensation (in years)	'1 year 3 months 28 days	'	'	'	'	'
Impact on basic earnings (loss) per common share (in dollars per share)	($0.17)	($0.21)	($0.31)	'	'	'

Litigation_Details

Litigation (Details) (USD $)	0 Months Ended				0 Months Ended
In Thousands, unless otherwise specified	Feb. 07, 2014	Jan. 24, 2014	17-May-11	29-May-13	Jun. 02, 2014	Jul. 03, 2014
					Subsequent Event [Member]	Pending Litigation [Member]
						Subsequent Event [Member]
Loss Contingencies [Line Items]	'	'	'	'	'	'
Litigation settlement	'	$1,250	'	'	'	$2,950
Damages sought, minimum	'	'	3,000	'	'	'
Damages sought for loss of vested warrants	'	'	2,687	'	'	'
Reimbursement due from plaintiff	'	'	'	'	9	'
Estimated possible loss	'	'	'	1,889	'	'
Indemnity agreement amount	$500	'	'	'	'	'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (Commodity Contract [Member], Not Designated as Hedging Instrument [Member], USD $)	Apr. 30, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Commodity derivative asset	$114	$0
Commodity derivative liability	-7,321	-842
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Commodity derivative asset	114	'
Commodity derivative liability	-7,321	-842
Total	($7,207)	($842)

Oil_and_Gas_Properties_and_Equ2

Oil and Gas Properties and Equipment (Details) (USD $)	Apr. 30, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Property costs	'	'
Proved property	$467,740	$332,241
Unproved property	243,107	196,500
Total property costs	710,847	528,741
Less: Accumulated depletion	-66,020	-37,427
Oil and gas properties, net	$644,827	$491,314

Oil_and_Gas_Properties_and_Equ3

Oil and Gas Properties and Equipment (Details 1) (USD $)	Apr. 30, 2014	Apr. 30, 2013
In Thousands, unless otherwise specified
Equipment	'	'
Equipment, gross	$45,707	$43,823
Less: Accumulated depreciation	-10,338	-6,252
Equipment, net	35,369	37,571
Machinery and Equipment [Member]	'	'
Equipment	'	'
Equipment, gross	7,759	7,413
Vehicles [Member]	'	'
Equipment	'	'
Equipment, gross	1,877	1,851
Aircraft [Member]	'	'
Equipment	'	'
Equipment, gross	'	476
Buildings [Member]	'	'
Equipment	'	'
Equipment, gross	2,726	2,725
Office Equipment [Member]	'	'
Equipment	'	'
Equipment, gross	1,108	759
Leasehold Improvements [Member]	'	'
Equipment	'	'
Equipment, gross	527	482
Drilling Rigs [Member]	'	'
Equipment	'	'
Equipment, gross	30,210	30,117
Payment on Drilling Rig [Member]	'	'
Equipment	'	'
Equipment, gross	$1,500	'

Oil_and_Gas_Properties_and_Equ4

Oil and Gas Properties and Equipment (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Depreciation, depletion and amortization	'	'	'
Depletion of oil and gas related assets	$29,292	$9,803	$12,537
Depreciation and amortization of equipment	4,236	3,367	773
Total	$33,528	$13,170	$13,310

Oil_and_Gas_Properties_and_Equ5

Oil and Gas Properties and Equipment (Details Textual) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014
Property, Plant and Equipment [Abstract]	'
Impairment charge	$168

Major_Customers_and_Concentrat1

Major Customers and Concentrations of Credit Risk (Details) (USD $)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Concentration Risk [Line Items]	'	'	'
Credit losses	'	'	'
Revenue [Member]	'	'	'
Concentration Risk [Line Items]	'	'	'
Concentration risk (percent)	88.00%	80.00%	100.00%
Accounts receivable [Member]	'	'	'
Concentration Risk [Line Items]	'	'	'
Concentration risk (percent)	5.00%	55.00%	'
Cash [Member]	'	'	'
Concentration Risk [Line Items]	'	'	'
FDIC uninsured amount	5,062,000	'	'
FDIC insured amount	$250,000	'	'

Alaska_Production_Credits_Deta

Alaska Production Credits (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014		Apr. 30, 2013	Apr. 30, 2012
State Production Credit Receivable, Annual Loss Credits [Roll Forward]	'		'	'
Balance, April 30, 2013	$12,713		'	'
Applications for carried-forward annual loss credits	16,342	[1]	3,268	'
Applications for expenditure and exploration based credits	41,841	[1]	'	'
Cash collections for carried-forward annual loss credits	-3,244		'	'
Cash collections for expenditure and exploration based credits	-18,531		'	'
Balance, April 30, 2014	$49,121		$12,713	'
[1]	Applications for carried-forward annual loss credits for expenditure and exploration based credits are recorded net of established reserves and also include revisions to prior period applications, if applicable.

Alaska_Production_Credits_Deta1

Alaska Production Credits (Details Textual) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014		Apr. 30, 2013	Apr. 30, 2012
Alaska Production Tax Credits [Line Items]	'		'	'
Carried-forward annual loss credits	$16,342	[1]	$3,268	'
Expenditure and exploration credits	54,570		14,547	'
State production credits receivable	$49,121		$12,713	'
43.55.023(a)(1) [Member]	'		'	'
Alaska Production Tax Credits [Line Items]	'		'	'
Alaska capital expenditure credit (percent)	20.00%		20.00%	'
43.55.023(1)(1) [Member]	'		'	'
Alaska Production Tax Credits [Line Items]	'		'	'
Alaska capital expenditure credit (percent)	40.00%		40.00%	'
43.55.023(a)(2) [Member]	'		'	'
Alaska Production Tax Credits [Line Items]	'		'	'
Alaska capital exploration credit (percent)	20.00%		20.00%	'
43.55.023(1)(2) [Member]	'		'	'
Alaska Production Tax Credits [Line Items]	'		'	'
Alaska capital exploration credit (percent)	40.00%		40.00%	'
43.55.023(b) [Member]	'		'	'
Alaska Production Tax Credits [Line Items]	'		'	'
Alaska carried-forward annual loss credit (percent)	25.00%		25.00%	'
43.55.025 [Member]	'		'	'
Alaska Production Tax Credits [Line Items]	'		'	'
Seismic exploration credits (percent)	40.00%		40.00%	'
[1]	Applications for carried-forward annual loss credits for expenditure and exploration based credits are recorded net of established reserves and also include revisions to prior period applications, if applicable.

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012	Feb. 03, 2014	Sep. 18, 2013	Jul. 08, 2013	Jan. 08, 2013	Jul. 11, 2012	20-May-11	31-May-10
Related Party Transaction [Line Items]	'	'	'	'	'	'	'	'	'	'
Amount paid to former related party	$1,060	$680	$463	'	'	'	'	'	'	'
Due from related parties	24	11	'	'	'	'	'	'	'	'
Payment to company by related party	3	'	'	'	'	'	'	'	'	'
Related payable recorded	157	620	'	'	'	'	'	'	'	'
Related receivable recorded	0	593	'	'	'	'	'	'	'	'
Amount borrowed	'	'	'	'	'	'	'	'	'	3,071
Ownership of consolidated entity (percent)	1.00%	'	'	'	'	'	'	'	'	'
Obligations of note payable repaid (percent)	'	'	'	100.00%	'	'	'	'	'	'
Minimum ownership of outstanding stock (percent)	5.00%	'	'	'	'	'	'	'	'	'
Warrants issued (in shares)	'	'	'	'	300,000	'	'	'	'	'
Exercise price (in dollars per share)	'	'	'	'	6.63	4.15	3.56	5.28	5.51	'
Minimum [Member]	'	'	'	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'	'	'	'
Compensation	120	'	'	'	'	'	'	'	'	'
H&H Industrial [Member]	'	'	'	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'	'	'	'
Amount paid to related party	2,003	1,024	632	'	'	'	'	'	'	'
William Weakley [Member]	'	'	'	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'	'	'	'
Amount paid to related party	5	'	'	'	'	'	'	'	'	'
Immediate Family Member 1 [Member]	'	'	'	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'	'	'	'
Compensation	161	'	'	'	'	'	'	'	'	'
Immediate Family Member 2 [Member]	'	'	'	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'	'	'	'
Compensation	$148	'	'	'	'	'	'	'	'	'

Subsequent_Events_Details

Subsequent Events (Details) (Subsequent Event [Member], London Interbank Offered Rate (LIBOR) [Member])	0 Months Ended
	Jun. 02, 2014
Range 1 [Member]	'
Subsequent Event [Line Items]	'
Spread above LIBOR (percent)	3.00%
Undrawn commitment fee rate (percent)	0.50%
Range 2 [Member]	'
Subsequent Event [Line Items]	'
Spread above LIBOR (percent)	3.25%
Undrawn commitment fee rate (percent)	0.50%
Range 3 [Member]	'
Subsequent Event [Line Items]	'
Spread above LIBOR (percent)	3.50%
Undrawn commitment fee rate (percent)	0.75%
Range 4 [Member]	'
Subsequent Event [Line Items]	'
Spread above LIBOR (percent)	3.75%
Undrawn commitment fee rate (percent)	0.75%
Range 5 [Member]	'
Subsequent Event [Line Items]	'
Spread above LIBOR (percent)	4.00%
Undrawn commitment fee rate (percent)	0.75%

Subsequent_Events_Details_1

Subsequent Events (Details 1) (Subsequent Event [Member])	0 Months Ended
	Jun. 02, 2014
Range 1 [Member]	'
Subsequent Event [Line Items]	'
Lower range or borrowing base utilization (percent)	0.00%
Higher range of borrowing base utilization (percent)	24.00%
Range 2 [Member]	'
Subsequent Event [Line Items]	'
Lower range or borrowing base utilization (percent)	25.00%
Higher range of borrowing base utilization (percent)	49.00%
Range 3 [Member]	'
Subsequent Event [Line Items]	'
Lower range or borrowing base utilization (percent)	50.00%
Higher range of borrowing base utilization (percent)	74.00%
Range 4 [Member]	'
Subsequent Event [Line Items]	'
Lower range or borrowing base utilization (percent)	75.00%
Higher range of borrowing base utilization (percent)	89.00%
Range 5 [Member]	'
Subsequent Event [Line Items]	'
Lower range or borrowing base utilization (percent)	90.00%
Higher range of borrowing base utilization (percent)	100.00%

Subsequent_Events_Details_Text

Subsequent Events (Details Textual) (USD $)	0 Months Ended		0 Months Ended			0 Months Ended
	Nov. 22, 2013	Apr. 30, 2014	Jul. 04, 2014	Jul. 07, 2014	8-May-14	8-May-14	Jul. 07, 2014
			Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]
						Pending Merger [Member]	Maximum [Member]
						bbl
						mi
						gal
						MW
						Pipeline
						Well
						tank
						facility
Subsequent Event [Line Items]	'	'	'	'	'	'	'
Capital lease amount	'	'	'	$3,250,000	'	'	$5,000,000
Acquisition cost	59,557,000	'	'	'	'	9,000,000	'
Working interest acquired (percent)	100.00%	'	'	'	'	67.50%	'
Ownership in nearby leases (percent)	'	'	'	'	'	100.00%	'
ASRC Exploration, LLC working interest ownership (percent)	'	1.00%	'	'	32.50%	'	'
Daily processing capacity (in barrels per day)	'	'	'	'	'	38,500	'
Number of diesel storage tanks	'	'	'	'	'	1	'
Diesel storage tank holding capacity (in gallons)	'	'	'	'	'	500,000	'
Power generation (in megawatts)	'	'	'	'	'	20	'
Number of grind and inject solid waste disposal facilities	'	'	'	'	'	1	'
Airstrip length (in miles)	'	'	'	'	'	1	'
Number of pipelines	'	'	'	'	'	2	'
Length per pipeline (in miles)	'	'	'	'	'	25	'
Number of Class 1 disposal wells	'	'	'	'	'	1	'
Gross BOPD production (in barrels per day)	'	'	'	'	'	1,100	'
Net BOPD production (in barrels per day)	'	'	'	'	'	600	'
Payment for Glacier Rig and related equipment	'	'	700,000	'	'	'	'
Payment due upon finalized sale	'	'	$6,300,000	'	'	'	'

Subsequent_Events_Details_Text1

Subsequent Events (Details Textual 1) (USD $)	0 Months Ended
	Feb. 03, 2014	Jun. 24, 2014	Jun. 02, 2014	Jun. 02, 2014	Jun. 02, 2014
		Subsequent Event [Member]	Subsequent Event [Member]	Minimum [Member]	Maximum [Member]
				Subsequent Event [Member]	Subsequent Event [Member]
				London Interbank Offered Rate (LIBOR) [Member]	London Interbank Offered Rate (LIBOR) [Member]
Subsequent Event [Line Items]	'	'	'	'	'
Revolving credit facility	'	'	$250,000,000	'	'
Borrowing base	175,000,000	'	60,000,000	'	'
Spread above LIBOR (percent)	'	'	'	3.00%	4.00%
Amount borrowed	$175,000,000	$10,000,000	$20,000,000	'	'
Original issue discount (percent)	'	'	1.00%	'	'

Subsequent_Events_Details_Text2

Subsequent Events (Details Textual 2) (USD $)	0 Months Ended				12 Months Ended	0 Months Ended		12 Months Ended	0 Months Ended
	Mar. 03, 2014	Dec. 02, 2013	Sep. 03, 2013	Jun. 03, 2013	Apr. 30, 2014	Mar. 03, 2014	Dec. 02, 2013	Apr. 30, 2014	Jun. 02, 2014	Jun. 02, 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 D Preferred Stock [Member]	Series D Preferred Stock [Member]	Series D Preferred Stock [Member]	Subsequent Event [Member]	Subsequent Event [Member]
									Series C Preferred Stock [Member]	Series D Preferred Stock [Member]
Subsequent Event [Line Items]	'	'	'	'	'	'	'	'	'	'
Dividend paid (in dollars per share)	$0.67	$0.67	$0.67	$0.67	'	'	'	'	$0.67	'
Cumulative declared dividend rate per annum (percent)	'	'	'	'	10.75%	'	'	'	'	'
Liquidation preference (in dollars per share)	'	'	'	'	$25	'	'	'	'	'
Dividend paid (in dollars per share)	'	'	'	'	'	$0.66	$0.44	'	'	$0.66
Cumulative dividend rate per annum (percent)	'	'	'	'	'	'	'	10.50%	'	'
Liquidation preference (in dollars per share)	'	'	'	'	'	'	'	$25	'	'

Subsequent_Events_Details_Text3

Subsequent Events (Details Textual 3) (USD $)	0 Months Ended
In Thousands, unless otherwise specified	Jan. 24, 2014	Jul. 03, 2014
		Pending Litigation [Member]
		Subsequent Event [Member]
Subsequent Event [Line Items]	'	'
Litigation settlement	$1,250	$2,950

Supplemental_Oil_and_Gas_Discl2

Supplemental Oil and Gas Disclosures (Unaudited) (Details) (USD $)	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
In Thousands, unless otherwise specified
Natural gas and oil properties:	'	'	'
Proved properties	$467,740	$332,241	$321,066
Unproved properties	243,107	196,500	182,704
Gross capitalized costs	710,847	528,741	503,770
Accumulated depletion	-66,020	-37,427	-27,968
Net capitalized costs	$644,827	$491,314	$475,802

Supplemental_Oil_and_Gas_Discl3

Supplemental Oil and Gas Disclosures (Unaudited) (Details 1) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Property acquisition costs	'	'	'
Proved properties	$54,535	$689	'
Unproved properties	7,564	704	785
Acquisition costs	62,099	1,393	785
Exploration costs	1,713	1,268	180
Development costs	133,778	24,968	6,773
Total	$197,590	$27,629	$7,738

Supplemental_Oil_and_Gas_Discl4

Supplemental Oil and Gas Disclosures (Unaudited) (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Oil and Gas Exploration and Production Industries Disclosures [Abstract]	'	'	'
Production revenues	$69,469	$29,915	$32,493
Lease operating expense	-20,187	-22,288	-11,305
Transportation costs	-5,599	-2,410	-3,556
Alaska carried-forward annual loss credits, net	16,342	3,268	'
Depletion	-35,212	-13,041	-13,094
Results of operations for producing activities (excluding corporate overhead and interest costs)	$24,813	($4,556)	$4,538

Supplemental_Oil_and_Gas_Discl5

Supplemental Oil and Gas Disclosures (Unaudited) (Details 3)	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
	MBbls	MBbls	MBbls
MBbls [Member] | Crude Oil [Member]	'	'	'
Proved reserves	'	'	'
Balance	7,954	8,534	8,948
Extensions, discoveries and other additions	2,113	26	94
Revisions of previous estimates	-3,286	-317	-124
Acquisition of reserves in place	'	6	'
Production	-685	-295	-384
Balance	6,096	7,954	8,534
Proved developed reserves	4,264	1,697	2,325
Proved undeveloped reserves	1,832	6,257	6,209
MMcf [Member] | Natural Gas [Member]	'	'	'
Proved reserves	'	'	'
Balance	3,940	4,557	3,243
Extensions, discoveries and other additions	'	35	1,850
Revisions of previous estimates	-231	-519	-359
Acquisition of reserves in place	24,726	'	'
Production	-794	-133	-177
Balance	27,641	3,940	4,557
Proved developed reserves	12,202	513	2,601
Proved undeveloped reserves	15,439	3,427	1,956
MBoe [Member] | Barrels of Oil Equivalent [Member]	'	'	'
Proved reserves	'	'	'
Balance (in MBoe)	8,611	9,294	9,489
Extensions, discoveries and other additions (in MBoe)	2,113	32	402
Revisions of previous estimates (in MBoe)	-3,325	-404	-183
Acquisition of reserves in place (in MBoe)	4,121	6	'
Production (in MBoe)	-817	-317	-414
Balance (in MBoe)	10,703	8,611	9,294
Proved developed reserves (in MBoe)	6,298	1,783	2,759
Proved undeveloped reserves (in MBoe)	4,405	6,828	6,535

Supplemental_Oil_and_Gas_Discl6

Supplemental Oil and Gas Disclosures (Unaudited) (Details 4) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Oil and Gas Exploration and Production Industries Disclosures [Abstract]	'	'	'
Future cash flows	$810,184	$801,134	$894,027
Future production costs and taxes	-218,407	-178,779	-158,938
Future development costs	-90,812	-72,434	-75,332
Future income tax expense	-117,263	-150,568	-217,312
Future cash flows	383,702	399,353	442,445
Discount at 10% for timing of cash flows	-99,574	-124,905	-139,242
Discounted future net cash flows from proved reserves	$284,128	$274,448	$303,203

Supplemental_Oil_and_Gas_Discl7

Supplemental Oil and Gas Disclosures (Unaudited) (Details 5) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]	'	'	'
Balance, beginning of year	$274,448	$303,203	$206,801
Sales, net of production costs and taxes	-43,683	-5,217	-17,632
Changes in prices and production costs	-45,258	-59,253	116,689
Extensions, discoveries and other additions	100,868	1,302	58,906
Acquisition of reserves in place	73,946	295	'
Changes in estimated future development costs	11,744	-2,856	7,641
Development costs incurred	10,131	5,522	6,773
Revisions of previous quantity estimates	-143,565	-21,828	-42,857
Net changes in income taxes	15,502	49,486	-48,571
Sales of reserves in place	'	'	'
Accretion of discount	37,176	39,472	30,503
Changes in timing and other	-7,181	-35,678	-15,050
Balance, end of year	$284,128	$274,448	$303,203

Supplemental_Oil_and_Gas_Discl8

Supplemental Oil and Gas Disclosures (Unaudited) (Details Textual)	Apr. 30, 2014	Apr. 30, 2014	Feb. 04, 2014
	Cook Inlet [Member]	Appalachian Region [Member]	North Fork Acquisition [Member]
			Natural Gas [Member]
			MMcf
Supplemental Oil and Gas Disclosures [Line Items]	'	'	'
Proved undeveloped reserves acquired (in MMcf)	'	'	13,273
Price per barrel of oil (in dollars per barrel)	102.21	86.37	'
Price per MMcf of natural gas (in dollars per MMcf)	6.9	2.27	'