The number of consecutive, periodic payment installments in which the debt is to be repaid.

No definition available.

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Namespace Prefix:	ship_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The required security cover threshold (expressed as a percentage) as defined in the loan facility agreement.

+ References

No definition available.

+ Details

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
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Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 835
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-Name Accounting Standards Codification
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

+ References

+ Details

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

- Definition

Amount of the required periodic payments applied to principal.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of payment greater than the preceding installment payments to be paid at final maturity date of debt.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Indicates type of variable interest rate on debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
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Namespace Prefix:	us-gaap_
Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Data Type:	na
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Long-Term Debt and Other Financial Liabilities, October 2024 Alpha Bank Loan Facility (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2025 USD ($) Installment	Dec. 31, 2024 USD ($)	Oct. 21, 2024 USD ($)
Senior Long-Term Debt [Abstract]
Balance outstanding	$ 293,958	$ 261,451
October 2024 Alpha Bank Loan Facility [Member]
Senior Long-Term Debt [Abstract]
Face amount			$ 34,000
Margin on variable rate	2.40%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	Term SOFR [Member]
Term of loan	5 years
Final balloon payment	$ 14,800
Balance outstanding	$ 29,200
October 2024 Alpha Bank Loan Facility [Member] \| Minimum [Member]
Senior Long-Term Debt [Abstract]
Margin on variable rate	0.75%
Security cover ratio	125.00%
October 2024 Alpha Bank Loan Facility [Member] \| First Four Installments [Member]
Senior Long-Term Debt [Abstract]
Number of payment installments \| Installment	4
Frequency of periodic payment	quarterly
Installment payment	$ 1,200
October 2024 Alpha Bank Loan Facility [Member] \| Last Sixteen Installments [Member]
Senior Long-Term Debt [Abstract]
Number of payment installments \| Installment	16
Frequency of periodic payment	quarterly
Installment payment	$ 900