Name:	esi_AppraisedValuePercentageOfProperties
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Data Type:	num:percentItemType
Balance Type:	na
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The required ratio of assets to liabilities pursuant to the agreements under the PEAKS Guarantee.

No definition available.

Name:	esi_AssetsToLiabilitiesRatio
Namespace Prefix:	esi_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

The amount of outstanding principal owed under a debt agreement.

No definition available.

Name:	esi_DebtOutstandingPrincipalBalance
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The estimated fair value of the debt at the time of consolidation of the variable interest entity.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Payments made under the Guarantee related to the PEAKS Program.

No definition available.

Name:	esi_GuaranteePaymentsRelatedToPEAKSProgram
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The maximum amount of letters of credits available to be issued under the credit agreement.

No definition available.

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Period Type:	instant

The maximum borrowing capacity under the credit facility that was revised as a result of an amendment to the credit agreement.

No definition available.

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Period Type:	instant

The minimum base interest rate applicable to the senior debt.

No definition available.

Name:	esi_MinimumApplicableBaseInterestRate
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Balance Type:	na
Period Type:	instant

Number Of Parcels Of Land

No definition available.

Name:	esi_NumberOfParcelsOfLand
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Balance Type:	na
Period Type:	duration

The amount of accrued discount on debt at the time the debt was included on the consolidated financial statements of the reporting entity.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

The limitation on asset dispositions as specified in the credit facility prior to revision.

No definition available.

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Balance Type:	credit
Period Type:	instant

The amount of permitted indebtedness allowed under the original credit agreement.

No definition available.

Name:	esi_PriorPermittedIndebtedness
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The percentage of the amount of certain issued letters of credit that are required to be collateralized with cash.

No definition available.

Name:	esi_RequiredCashCollateralForLettersOfCredit1
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The percentage of the amount of certain issued letters of credit that are required to be collateralized with cash.

No definition available.

Name:	esi_RequiredCashCollateralForLettersOfCredit2
Namespace Prefix:	esi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The revised limitation on asset dispositions as specified in the amended credit facility.

No definition available.

Name:	esi_RevisedLimitationOnAssetDispositions
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of permitted indebtedness allowed under the amended credit agreement.

No definition available.

Name:	esi_RevisedPermittedIndebtedness
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Period Type:	instant

Sale Leaseback Transaction Costs

No definition available.

Name:	esi_SaleLeasebackTransactionCosts
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Balance Type:	credit
Period Type:	duration

The amount of senior debt issued by a variable interest entity which is consolidated with the reporting entity.

No definition available.

Name:	esi_SeniorDebtIssuedByVariableInterestEntity
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Additional fees paid to lenders for letter of credit exposures.

No definition available.

Name:	esi_TickingFeeRate
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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-Subparagraph (SX 210.5-03.8)
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
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Data Type:	num:percentItemType
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Period Type:	duration

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Period Type:	instant

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Period Type:	duration

Amount of the cost of borrowed funds accounted for as interest expense for debt.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 20, 22
-Article 5

Name:	us-gaap_LineOfCredit
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Date the credit facility terminates, in CCYY-MM-DD format.

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Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

The effective interest rate during the reporting period.

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

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.

No definition available.

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

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

No definition available.

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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-Paragraph 1
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Section S99
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-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
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-Paragraph 20, 22
-Article 5

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of long-term debt, after unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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

Name:	us-gaap_FinancialInstrumentAxis=esi_LetterOfAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_GuaranteeObligationsByNatureAxis=esi_PeaksGuaranteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_DebtInstrumentAxis=esi_CreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_DebtInstrumentAxis=esi_AmendedCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_DebtInstrumentAxis=esi_PeaksSeniorDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_CreditFacilityAxis=esi_FourthAmendmentMember
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Data Type:	na
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