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_
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Balance Type:	na
Period Type:	duration

- 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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Namespace Prefix:	us-gaap_
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Balance Type:	na
Period Type:	duration

- Definition

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

+ 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

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
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Namespace Prefix:	us-gaap_
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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

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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

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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

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-Topic 942
-SubTopic 470
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-Section 50
-Paragraph 3
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Period Type:	duration

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

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-Name Accounting Standards Codification
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Excludes repayments of tax exempt secured debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
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-Section 45
-Paragraph 15
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-15

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

- References

No definition available.

+ Details

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

- Details

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- Details

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Long-Term Debt and Other Financial Liabilities, Sinopac Loan Facility (Details) $ in Thousands		12 Months Ended
	Sep. 10, 2025 USD ($)	Dec. 31, 2025 USD ($) Installment	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 10, 2021 USD ($)
Senior Long-Term Debt [Abstract]
Payment of long-term debt		$ 123,333	$ 73,038	$ 88,742
Loss on extinguishment of debt		$ (1,663)	$ (653)	$ (540)
Sinopac Loan Facility [Member]
Senior Long-Term Debt [Abstract]
Face amount					$ 15,000
Margin on variable rate		3.50%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]		Term SOFR [Member]
Term of loan		5 years
Final balloon payment		$ 6,720
Payment of long-term debt	$ 9,030
Loss on extinguishment of debt		$ 63
Sinopac 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		$ 530
Sinopac 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		$ 385