XML 87 R41.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Stockholders' Equity (Details) (USD $) | 12 Months Ended | 1 Months Ended | 12 Months Ended | 1 Months Ended | 12 Months Ended | 1 Months Ended |  |  |  | 1 Months Ended |  |  | 1 Months Ended |  |  | 1 Months Ended |  | 1 Months Ended |  |  |  |  |  | 12 Months Ended | 1 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jun. 30, 2012 | Jun. 30, 2011 | Jun. 30, 2010 | Oct. 31, 2010 Restricted stock | Aug. 31, 2010 Restricted stock | Mar. 31, 2010 Restricted stock | Jun. 30, 2012 Restricted stock | Dec. 31, 2010 Stock options | Jul. 31, 2010 Stock options | Jun. 30, 2010 Stock options | Jun. 30, 2012 Stock options | Jun. 30, 2011 Stock options | Jun. 30, 2010 Stock options | Dec. 31, 2010 Common stock | Oct. 31, 2010 Common stock | Aug. 31, 2010 Common stock | Jul. 31, 2010 Common stock | Jun. 30, 2010 Common stock | Mar. 31, 2010 Common stock | Jun. 30, 2012 Common stock | Sep. 10, 2010 Common stock | Sep. 08, 2009 Common stock | Dec. 31, 2010 Outside directors Restricted stock director | Dec. 31, 2009 Outside directors Restricted stock director | Dec. 31, 2010 Outside directors Common stock | Dec. 31, 2009 Outside directors Common stock | Feb. 28, 2011 Consultant Stock options | Feb. 28, 2011 Consultant Common stock | Jun. 22, 2006 Placement agent | Nov. 30, 2004 Placement agent | Apr. 30, 2010 Placement agent Common stock | Nov. 30, 2009 Placement agent Common stock | May 06, 2005 Laird Q. Cagan | Jun. 30, 2004 Laird Q. Cagan | May 31, 2012 Laird Q. Cagan Common stock | Mar. 31, 2011 Laird Q. Cagan Common stock | May 26, 2004 Laird Q. Cagan CMCP | Oct. 31, 2009 Laird Q. Cagan CMCP Common stock | Aug. 31, 2011 2004 Stock Plan Restricted stock | Sep. 30, 2010 2004 Stock Plan Restricted stock | Sep. 30, 2009 2004 Stock Plan Restricted stock | Sep. 10, 2010 2004 Stock Plan Restricted stock | Jul. 02, 2010 2004 Stock Plan Restricted stock | Jun. 19, 2010 2004 Stock Plan Restricted stock | Feb. 06, 2010 2004 Stock Plan Restricted stock | Sep. 08, 2009 2004 Stock Plan Restricted stock | Jun. 30, 2009 2004 Stock Plan Stock options | Aug. 31, 2011 2004 Stock Plan Common stock | Sep. 30, 2010 2004 Stock Plan Common stock | Jul. 31, 2010 2004 Stock Plan Common stock | Jun. 30, 2010 2004 Stock Plan Common stock | Feb. 28, 2010 2004 Stock Plan Common stock | Sep. 30, 2009 2004 Stock Plan Common stock | Dec. 31, 2011 2004 Stock Plan Outside directors Restricted stock director | Dec. 31, 2011 2004 Stock Plan Outside directors Common stock | Sep. 30, 2011 2004 Stock Plan Contractor Stock options | Sep. 30, 2011 2004 Stock Plan Contractor Common stock
Number of shares of common stock issued for payment of bonuses |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 106,927 |  |  |  | 138,224 |  |  |  |
Value of shares of common stock issued for payment of bonuses |  | $ 587,033 | $ 370,440 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 587,033 |  |  |  | $ 370,440 |  |  |  |
Number of shares issued |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4,845 | 30,233 |  |  | 20,000 |  |  |  |  |  | 28,047 | 42,317 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 161,861 | 240,478 |  |  |  | 324,597 |  | 34,245 |  |
Value of shares issued | 34 | 28 | 42 |  |  |  |  |  |  |  |  |  |  |  | 29,118 | 156,000 |  |  | 90,000 |  |  |  |  |  | 168,000 | 168,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 249,955 |  |
Share price on date of issuance (in dollars per share) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 8.34 | $ 5.49 | $ 2.68 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total unrecognized stock-based compensation expense |  |  |  |  |  |  | $ 2,118,741 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,029,436 |  |  | $ 1,320,224 |  |  |  | $ 869,917 |  |  |  |  |  |  |  |  |  |  |
Period for recognition of stock-based compensation expense (vesting period) |  |  |  |  |  |  | 2 years 3 months 18 days |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4 years | 4 years | 4 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Vesting period |  |  |  | 4 years | 4 years | 4 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1 year | 1 year |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4 years |  |  |  |  |  |  | 1 year |  |  |
Number of shares of common stock issued through a net cashless exercise of a placement warrant |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7,377 | 5,833 |  |  | 65,261 | 58,350 |  | 119,795 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Right to purchase number of shares of common stock against warrants |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 12,000 | 10,000 |  |  | 91,200 | 66,943 |  |  | 165,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Exercise price of warrants (in dollars per share) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 2.25 | $ 1.50 |  |  | $ 2.50 | $ 1.00 |  |  | $ 1.00 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of directors to whom shares of restricted common stock were issued as a part of the board compensation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4 | 4 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5 |  |  |
Restricted common stock forfeited by an employee (in shares) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4,215 | 91,902 | 38,182 |  |  |  |  |
Unrecognized stock-based compensation expense, forfeited shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 11,621 | 436,522 | 187,965 |  |  |  |  |  |  |  |  |  |  |  |
Stock options exercised (in shares) |  |  |  |  |  |  |  |  |  |  | 20,000 | 86,875 | 3,000 | 30,000 |  |  | 6,875 | 3,000 |  |  |  |  |  |  |  |  |  | 50,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 20,000 |
Net share issuance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7,941
Exercise price of options (in dollars per share) |  |  |  |  |  |  |  | $ 0.001 | $ 2.33 | $ 1.10 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1.80 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 4.10 |

X
- Definition The number of shares issued as a result of the cashless exercise of warrants during the period, net of shares cancelled in lieu of payment of cash consideration. + References No definition available. + Details
Name: | epm_ClassOfWarrantOrRightWarrantsExercisedSharesIssuedNetOfSharesCancelledInLieuOfCashPayment
Namespace Prefix: | epm_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate unrecognized cost of share-based awards, other than options, made to employees under an equity-based compensation plan, as of the date of forfeiture of the shares. + References No definition available. + Details
Name: | epm_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptionsForfeitedShares
Namespace Prefix: | epm_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the number of directors to whom shares of common stock were granted as a part of the board compensation. + References No definition available. + Details
Name: | epm_NumberOfDirectorsToWhomAwardsWereGranted
Namespace Prefix: | epm_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of shares issued as a result of the cashless exercise of share options (or share units) during the period, net of shares cancelled in lieu of payment of cash consideration. + References No definition available. + Details
Name: | epm_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodSharesIssuedNetOfSharesCancelledInLieuOfCashPayment
Namespace Prefix: | epm_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The exercise price of each class of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(4)) -URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph i -Subparagraph 4 -Article 4 + Details
Name: | us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights
Namespace Prefix: | us-gaap_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition The specified number of securities that each class of warrants or rights outstanding give the holder the right but not the obligation to purchase from the issuer at a specific price, on or before a certain date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(2)) -URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph i -Subparagraph 2 -Article 4 + Details
Name: | us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate unrecognized cost of share-based awards, other than options, made to employees under an equity-based compensation plan, that have yet to vest. + References No definition available. + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average price at which option holders acquired shares when converting their stock options into shares. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Price of a single share of a number of saleable stocks of a company. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 + Details
Name: | us-gaap_SharePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares related to Restricted Stock Award forfeited during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 4, 5 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total number of shares issued during the period, including shares forfeited, as a result of Restricted Stock Awards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 4, 5 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Gross number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP). Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans. + References No definition available. + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of share options (or share units) exercised during the current period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.28,29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30 -Article 5 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate value of stock related to Restricted Stock Awards issued during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 + Details
Name: | us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gross value of stock (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP). Stock issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans. + References No definition available. + Details
Name: | us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration