Balance Sheet [Line Items]

No definition available.

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Period Type:	duration

- Definition

Contract Receivable Gross

+ References

No definition available.

+ Details

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

- Definition

Contracts receivable repayment term.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Number of customers.

+ References

No definition available.

+ Details

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

- Definition

Number of installments.

+ References

No definition available.

+ Details

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Namespace Prefix:	mind_
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Balance Type:	na
Period Type:	instant

- Definition

The weighted average interest rate charged on contract receivables maturing after one year.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 910
-SubTopic 310
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=68065756&loc=d3e49354-109356

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Amount billed to customers under long-term contracts or programs to be collected in the second fiscal year following the latest fiscal year. Excludes amounts due that have been withheld because of retainage provisions in a contract. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 910
-SubTopic 310
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=68065756&loc=d3e49354-109356

+ Details

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

- Definition

The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 958
-SubTopic 225
-Section 45
-Paragraph 11
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84241808&loc=d3e92212-112881

Reference 2: 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=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2420-110228

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84176398&loc=d3e2921-110230

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Balance Type:	debit
Period Type:	duration

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Balance Sheet - Additional Information (Detail)		3 Months Ended	12 Months Ended
Balance Sheet - Additional Information (Detail)	Jan. 31, 2018 USD ($)	Apr. 30, 2018 USD ($) customer	Jan. 31, 2018 USD ($) customer	Apr. 30, 2017 USD ($) Installment
Balance Sheet [Line Items]
Contracts receivable	$ 4,921,000	$ 4,402,000	$ 4,921,000
Number of customers due \| customer		4	4
Contracts receivable, interest rate	2.80%	2.70%	2.80%
Long-term contract receivable for sale of lease pool equipment				$ 3,800,000
Number of installments \| Installment				24
Impairment charges related to long-lived assets	$ 0	$ 0
Minimum
Balance Sheet [Line Items]
Contracts receivable repayment term		1 month
Maximum
Balance Sheet [Line Items]
Contracts receivable repayment term		40 months