Variable Interest Entities - Schedule of Payments Made to Entity Related to Guarantee Obligations (Parenthetical) (Detail) (CUSO [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014
CUSO [Member]
Variable Interest Entity [Line Items]
Recoveries from charged-off loans owed related to regular payments obligation	$ 466
Regular payments prior to consolidation	$ 4,556

The amount of recoveries from charged-off loans that were owed to the reporting entity by the variable interest entity that were offset against amounts the reporting entity owed to the variable interest entity.

No definition available.

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