The number of performance obligations.

No definition available.

Name:	mist_NumberOfPerformanceObligations
Namespace Prefix:	mist_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of ownership of common stock held by beneficial owner.

+ References

No definition available.

+ Details

Name:	mist_PercentageOfCommonSharesHeldByBeneficialOwner
Namespace Prefix:	mist_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Potential milestone payments in addition to recognized revenue.

+ References

No definition available.

+ Details

Name:	mist_PotentialRevenueFromCollaborativeArrangement
Namespace Prefix:	mist_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Non-refundable upfront cash payment received.

+ References

No definition available.

+ Details

Name:	mist_UpfrontMilestonePayment
Namespace Prefix:	mist_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 808
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479402/808-10-50-1

+ Details

Name:	us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of revenue from collaborative arrangement. Excludes revenue from contract with customer under Topic 606.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 808
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479402/808-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-SubTopic 10
-Topic 808
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479428/808-10-45-3

+ Details

Name:	us-gaap_RevenueFromCollaborativeArrangementExcludingRevenueFromContractWithCustomer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	srt_CounterpartyNameAxis=mist_CorxelMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Revenue (Details) $ in Thousands		12 Months Ended
Revenue (Details) $ in Thousands	May 15, 2021 USD ($)	Dec. 31, 2024 USD ($) item	Dec. 31, 2023 USD ($)
Collaboration revenue
Revenue		$ 0	$ 1,000
Number of performance obligations \| item		2
Corxel Pharmaceuticals
Collaboration revenue
Percentage of beneficial owner	6.10%
Upfront cash payment	$ 15,000
Potential milestone payments	$ 107,500