Assets, liabilities, revenues and expenses of foreign subsidiaries.

No definition available.

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Namespace Prefix:	elrc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Capital lease term.

+ References

No definition available.

+ Details

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

- Definition

Demonstration equipment.

+ References

No definition available.

+ Details

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

- Definition

Period for demonstration equipment included in other assets.

+ References

No definition available.

+ Details

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

- Details

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Namespace Prefix:	elrc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 720

-SubTopic 35

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848

+ Details

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

- Definition

Term of the lessee's leasing arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Cost incurred during the reporting period in transporting goods and services to customers. Includes freight-out costs.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18726-107790

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 45

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6408196&loc=d3e61069-111654

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Handling Costs

-URI http://asc.fasb.org/extlink&oid=6514758

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 45

-Section 45

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=21915142&loc=d3e60635-111653

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 45

-Section S99

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6408413&loc=d3e221937-122793

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Shipping Costs

-URI http://asc.fasb.org/extlink&oid=6525344

+ Details

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

- Details

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Namespace Prefix:
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Basis of Presentation - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 28, 2015	Feb. 28, 2014	Feb. 28, 2015	Feb. 28, 2014	May 31, 2014
Summary Of Significant Accounting Policies [Line Items]
Advertising expenses	$ 301us-gaap_AdvertisingExpense	$ 233us-gaap_AdvertisingExpense	$ 720us-gaap_AdvertisingExpense	$ 665us-gaap_AdvertisingExpense
Shipping and handling cost	847	915	2,968	2,997
Assets, liabilities, revenues and expenses of foreign subsidiaries			10.00%
Demonstration equipment	$ 9,581elrc_DemonstrationEquipment		$ 9,581elrc_DemonstrationEquipment		$ 6,659elrc_DemonstrationEquipment
Minimum
Summary Of Significant Accounting Policies [Line Items]
Operating lease agreements Period			1 year
Finance lease agreements Period			1 year
Maximum
Summary Of Significant Accounting Policies [Line Items]
Operating lease agreements Period			3 years
Finance lease agreements Period			3 years
Period for demonstration equipment included in other assets			2 years