The amount of assets used to determine the required Asset Liability Ratio under the PEAKS Program.

No definition available.

Name:	esi_AssetsForAssetLiabilityRatio
Namespace Prefix:	esi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The required ratio of assets to liabilities pursuant to the agreements under the PEAKS Guarantee.

+ References

No definition available.

+ Details

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

- Definition

The amount of outstanding principal owed under a debt agreement.

+ References

No definition available.

+ Details

Name:	esi_DebtOutstandingPrincipalBalance
Namespace Prefix:	esi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

Name:	esi_FairValueOfDebtUponConsolidation
Namespace Prefix:	esi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Payments made under the Guarantee related to the PEAKS Program.

+ References

No definition available.

+ Details

Name:	esi_GuaranteePaymentsRelatedToPEAKSProgram
Namespace Prefix:	esi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Payments made under the Guarantee related to the PEAKS Program that reduced the amount of the PEAKS Senior Debt.

+ References

No definition available.

+ Details

Name:	esi_GuaranteePaymentsRelatedToPeaksProgramDebt
Namespace Prefix:	esi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of liabilities used to determine the required Asset Liability Ratio under the PEAKS Program.

+ References

No definition available.

+ Details

Name:	esi_LiabilitiesForAssetLiabilityRatio
Namespace Prefix:	esi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum base interest rate applicable to the senior debt.

+ References

No definition available.

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

Name:	esi_OriginalAccruedDiscountOnDebt
Namespace Prefix:	esi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

Name:	esi_SeniorDebtIssuedByVariableInterestEntity
Namespace Prefix:	esi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ 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 210.5-02.22(a)(1))
-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 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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

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

+ References

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

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.

+ References

+ Details

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

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3291-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

Name:	us-gaap_RepaymentsOfLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=esi_PeaksTrustMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=esi_PeaksSeniorDebtMember
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_GuaranteeObligationsByNatureAxis=esi_PeaksProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt - PEAKS Trust Senior Debt - Additional Information (Detail) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Feb. 28, 2013 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	Jan. 31, 2010 USD ($)
Debt Instrument [Line Items]
Current liability		$ 15,634	$ 26,533	$ 20,105
Repayment of PEAKS Trust senior debt		6,976	15,646
PEAKS Guarantee				30,090
PEAKS Trust [Member]
Debt Instrument [Line Items]
Current liability		15,634	26,533	20,105
PEAKS Senior Debt [Member]
Debt Instrument [Line Items]
Aggregate principal amount of debt		300,000			$ 300,000
Estimated fair value of senior debt	$ 226,096
Outstanding balance	257,533	50,135	$ 81,273	57,111
Difference in Estimated Fair Value and Outstanding Principal Amount	$ 31,437
Current liability		$ 15,634
Debt instrument maturity date		Jan. 31, 2020
Variable rate percentage		5.50%
Minimum LIBOR rate applied		2.00%
Effective Interest Rate		14.50%	16.30%
PEAKS Senior Debt [Member] \| PEAKS Trust [Member]
Debt Instrument [Line Items]
Amount of assets for computation of Asset/Liability ratio		$ 68,273
Amount of liabilities for computation of Asset/Liability ratio		$ 50,135
PEAKS Senior Debt [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Required Asset/Liability ratio		1.05
PEAKS Senior Debt [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Required Asset/Liability ratio		1.40
PEAKS Program [Member]
Debt Instrument [Line Items]
Payments under PEAK Guarantee				$ 30,090
PEAKS Guarantee		$ 4,534	$ 13,637