Note 13 - Commitments and Contingencies (Details Textual) - Terms Sheet Settlement [Member] $ in Thousands	Sep. 21, 2020 USD ($)
Loss Contingency, All-in Cash Settlement Payment to Be Funded by Defendants And/Or Their Insurers Into an Escrow Account	$ 3,500
Loss Contingency, Percentage of Fund to Be Used Based on Management Duties and Business Judgment	55.00%
Loss Contingency, Percentage of Fund to Be Paid to Members of the Class or Current Stockholders of the Company out of the Escrow Account	45.00%
Loss Contingency, Expected Insurance Carries Reimbursement	$ 2,800
Loss Contingency, Expected Reimbursement From Related Affiliate	100
Loss Contingency Accrual, Ending Balance	3,750
Reimbursements from Insurance and Majority Shareholders [Member]
Loss Contingency, Receivable, Ending Balance	$ 5,700

Represents the all-in cash settlement payment to be funded by defendants and/or their insurers into an Escrow account.

No definition available.

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Namespace Prefix:	este_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the expected insurance carrier reimbursement.

+ References

No definition available.

+ Details

Name:	este_LossContingencyExpectedInsuranceCarrierReimbursement
Namespace Prefix:	este_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of expected reimbursement from related affiliate for a loss contingency.

+ References

No definition available.

+ Details

Name:	este_LossContingencyExpectedReimbursementFromRelatedAffiliate
Namespace Prefix:	este_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents percentage of fund to be paid to members of the class or current stockholders of the company out of the Escrow account.

+ References

No definition available.

+ Details

Name:	este_LossContingencyPercentageOfFundToBePaidToMembersOfTheClassOrCurrentStockholdersOfTheCompanyOutOfTheEscrowAccount
Namespace Prefix:	este_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the percentage of fund to be used based on management duties and business judgment.

+ References

No definition available.

+ Details

Name:	este_LossContingencyPercentageOfFundToBeUsedBasedOnManagementDutiesAndBusinessJudgment
Namespace Prefix:	este_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of loss contingency liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349

+ Details

Name:	us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of receivable related to a loss contingency accrual. For example, an insurance recovery receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12053-110248

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	srt_LitigationCaseAxis=este_TermsSheetSettlementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: