Sales price of long-lived, physical asset used in the normal conduct of business.

No definition available.

Name:	ship_PropertyPlantAndEquipmentSalesPrice
Namespace Prefix:	ship_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fixed monthly fees paid for arranging (directly or by subcontracting) for the crewing of the vessels, the day-to-day operations, inspections, maintenance, repairs, drydocking, purchasing, insurance and claims handling of vessels.

+ References

No definition available.

+ Details

Name:	ship_RelatedPartyTransactionMonthlyFixedManagementFee
Namespace Prefix:	ship_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	ship_TransactionsWithRelatedPartyAbstract
Namespace Prefix:	ship_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Term of lessor's sales-type 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_LessorSalesTypeLeaseTermOfContract1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, after allowance, of receivables classified as other, due within one year or the operating cycle, if longer.

+ References

No definition available.

+ Details

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

- Definition

Amount of revenue that is not accounted for under Topic 606.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(1))
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

+ Details

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

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_RelatedPartyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

Transactions with Related Parties (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	May 29, 2026	Dec. 31, 2025
Transactions with Related Party [Abstract]
Fees from related parties	$ 1,049	$ 1,345
Due from related parties	6,634			$ 9,100
Related Party [Member]
Transactions with Related Party [Abstract]
Fees from related parties	1,049	$ 1,345
Due from related parties	$ 6,634			$ 9,100
Related Party [Member] \| United [Member] \| Squireship [Member]
Transactions with Related Party [Abstract]
Sales price			$ 29,500
Related Party [Member] \| United [Member] \| Dukeship [Member]
Transactions with Related Party [Abstract]
Term of bareboat charter agreement	18 months
Seanergy Shipmanagement Corp. [Member] \| Related Party [Member] \| United [Member] \| Squireship [Member]
Transactions with Related Party [Abstract]
Fixed management fee per month	$ 14
Seanergy Shipmanagement Corp. [Member] \| Related Party [Member] \| United [Member] \| Dukeship [Member]
Transactions with Related Party [Abstract]
Fixed management fee per month	$ 14