Debt and Financing (Schedule of Fair Value Assumptions-15% Notes) (Details) - 15% Senior Secured Non-Convertible Note [Member]	9 Months Ended
Sep. 30, 2015 $ / shares
Debt Instrument [Line Items]
Weighted Term (years)	5 years 8 months 23 days
Level 1 Input [Member]
Debt Instrument [Line Items]
Stock price	$ 1.39
Level 1 Input [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Risk-free rate	1.30%
Level 1 Input [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Risk-free rate	1.70%
Level 2 Input [Member]
Debt Instrument [Line Items]
Yield Volatility	34.00%
Dividend yield	0.00%
Level 3 Input [Member] \| Claim Date Extended With Stock Appreciation Date Threshold Met [Member]
Debt Instrument [Line Items]
Scenario probability	14.50%
Level 3 Input [Member] \| Claim Date Extended With Stock Appreciation Date Threshold Not Met [Member]
Debt Instrument [Line Items]
Scenario probability	35.50%
Level 3 Input [Member] \| Claim Date Not Extended With Stock Appreciation Date Threshold Met [Member]
Debt Instrument [Line Items]
Scenario probability	10.50%
Level 3 Input [Member] \| Claim Date Not Extended With Stock Appreciation Date Threshold Not Met [Member]
Debt Instrument [Line Items]
Scenario probability	39.50%
Level 3 Input [Member] \| Future Draws [Member]
Debt Instrument [Line Items]
Scenario probability	50.00%
Level 3 Input [Member] \| No Future Draws [Member]
Debt Instrument [Line Items]
Scenario probability	50.00%

Fair Value Assumptions, Scenario probability

No definition available.

Name:	hnr_FairValueAssumptionsScenarioProbability
Namespace Prefix:	hnr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

+ 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=36462937&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueAssumptionsExpectedDividendRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_FairValueAssumptionsExpectedTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

+ Details

Name:	us-gaap_FairValueAssumptionsExpectedVolatilityRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Risk-free interest rate assumption used in valuing an instrument.

+ References

+ Details

Name:	us-gaap_FairValueAssumptionsRiskFreeInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

Name:	us-gaap_SharePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=hnr_SeniorSecuredNonConvertibleNote15Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=hnr_ClaimDateExtendedWithStockAppreciationDateThresholdMetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=hnr_ClaimDateExtendedWithStockAppreciationDateThresholdNotMetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=hnr_ClaimDateNotExtendedWithStockAppreciationDateThresholdMetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=hnr_ClaimDateNotExtendedWithStockAppreciationDateThresholdNotMetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=hnr_FutureDrawsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=hnr_NoFutureDrawsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: