Warrants (Details) - USD ($)	6 Months Ended
Jan. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Warrants [Abstract]
Warrants	2,515,000	2,015,000	150,000
Exercise Price	$ 0.15
Term	2 years
Volatility	323.00%
Risk Free Interest Rate	2.61%
Fair Value	$ 25,205

Agreed upon price for the exchange of the underlying asset.

No definition available.

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- Definition

Period the instrument, asset or liability is expected to be outstanding, 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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Period Type:	duration

- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

No definition available.

+ Details

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- Definition

Risk-free interest rate assumption used in valuing an instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	nmex_
Data Type:	num:percentItemType
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- References

No definition available.

+ Details

Name:	nmex_WarrantsAbstract
Namespace Prefix:	nmex_
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- Definition

Number of warrants or rights outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_ClassOfWarrantOrRightOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of expense (income) related to adjustment to fair value of warrant liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section 25
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=109262497&loc=d3e20148-110875

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