Represents number of subsidiaries.

No definition available.

Name:	asc_NumberOfSubsidiaries
Namespace Prefix:	asc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Option to extend, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	asc_OperatingLeaseOptionToExtend
Namespace Prefix:	asc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Refers to transaction costs related to the sale leaseback.

+ References

No definition available.

+ Details

Name:	asc_SaleLeasebackTransactionFees
Namespace Prefix:	asc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Indicates (true false) whether practical expedients are elected for not reassessing whether any expired or existing contract is or contains lease, lease classification for expired or existing lease, and initial direct cost for any existing lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (j)
-Publisher FASB
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479832/842-10-65-1

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:booleanItemType
Balance Type:	na
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 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
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-Subparagraph (c)
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-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-3

+ Details

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

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-3

+ Details

Name:	us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Term of lessor's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479773/842-30-50-3

+ Details

Name:	us-gaap_LessorOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

The historical cost of the asset(s) sold in connection with the sale of the property to another party and the lease of the property back to the seller.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 840
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 50
-Publisher FASB
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+ Details

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

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=asc_ArdmoreSealeaderMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=asc_CmbflShandongMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Leases (Details) $ in Millions	Mar. 08, 2024	Jun. 25, 2021 USD ($) subsidiary	Sep. 30, 2025	Mar. 09, 2024	Jul. 30, 2021
Lessee, Lease, Description [Line Items]
Lease agreement period			24 months		12 months
Operating Lease, Option to Extend	12 months
Lease, Practical Expedients, Package [true false]		true
Ardmore Sealeader
Lessee, Lease, Description [Line Items]
Lessor, Operating Lease, Term of Contract				12 months
CMBFL Shandong
Lessee, Lease, Description [Line Items]
Number of subsidiaries \| subsidiary		2
Gross proceeds		$ 49.0
Transaction fees		$ 1.0