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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from financing costs.

No definition available.

Name:	mist_DeferredTaxAssetsFinancingCosts
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from lease liability.

No definition available.

Name:	mist_DeferredTaxAssetsLeaseLiability
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from reserves.

No definition available.

Name:	mist_DeferredTaxAssetsReserves
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from right of use assets.

No definition available.

Name:	mist_DeferredTaxAssetsRightOfUseAssets
Namespace Prefix:	mist_
Data Type:	xbrli:monetaryItemType
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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from tax portion of in-process federal scientific research and development costs expensed.

No definition available.

Name:	mist_DeferredTaxAssetsTaxFederalSrEdInvestmentTaxCredits
Namespace Prefix:	mist_
Data Type:	xbrli:monetaryItemType
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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary difference from in-process research and development cost acquired in business combination or from joint venture formation or both.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-6

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.

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

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from property, plant, and equipment.

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Data Type:	xbrli:monetaryItemType
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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

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Balance Type:	credit
Period Type:	instant

- References

No definition available.