Rentals Under Noncancellable Operating Leases (Detail) - USD ($) $ in Thousands	12 Months Ended
May. 31, 2015	May. 31, 2014
Property Subject to or Available for Operating Lease [Line Items]
Operating lease gross	$ 12,512	$ 9,353
Accumulated depreciation	3,335	3,409
Net book value	$ 9,177	$ 5,943
Minimum
Property Subject to or Available for Operating Lease [Line Items]
Lease Period	1 year
Maximum
Property Subject to or Available for Operating Lease [Line Items]
Lease Period	3 years

Initial Lease Period

No definition available.

Name:	elrc_InitialLeasePeriod
Namespace Prefix:	elrc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of accumulated depreciation, by major property class, recorded on property subject to or available for lease as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6453916&loc=d3e41460-112716

+ Details

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

- Definition

Amount before accumulated depreciation of physical assets used in the normal conduct of business to produce goods and services subject to or available for lease.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6453916&loc=d3e41457-112716

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718

+ Details

Name:	us-gaap_PropertySubjectToOrAvailableForOperatingLeaseGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_PropertySubjectToOrAvailableForOperatingLeaseLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of property, by major property class, net of accumulated depreciation, subject to or available for lease as of the balance sheet date.

+ References

+ Details

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

- Details

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

- Details

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