Represents minimum net tangible assets outstanding subject to non redemption of outstanding shares.

No definition available.

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Namespace Prefix:	port_
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- Definition

Number of warrants or rights outstanding.

+ References

No definition available.

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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Balance Type:	na
Period Type:	instant

- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 946
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-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(16)(a))
-Publisher FASB
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-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(7))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, before refund, of cash paid to foreign, federal, state, and local jurisdictions as income tax.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
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-Topic 740
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-Topic 740
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-Topic 230
-SubTopic 10
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482913/230-10-50-2

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow to reacquire common stock during the period.

+ References

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

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
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-Topic 210
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2))
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-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-2

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=port_PrivatePlacementWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=port_SponsorMember
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Data Type:	na
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Period Type:

- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=port_SponsorMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassBMember
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- Details

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Period Type:

Subsequent Events (Details) - USD ($)	Jan. 15, 2025	Jan. 14, 2025	Mar. 31, 2025	Feb. 14, 2025	Dec. 31, 2024	Oct. 21, 2024	Sep. 30, 2024	Sep. 11, 2024	Dec. 31, 2023	May 25, 2023	Nov. 25, 2021
Subsequent Events
Common stock, par value (In dollars per share)								$ 0.0001
Class of warrant or right outstanding			23,200,000		23,200,000
Minimum net tangible assets outstanding subject to non redemption		$ 5,000,001				$ 5,000,001
Private placement warrants
Subsequent Events
Class of warrant or right outstanding			11,700,000		11,700,000
Sponsor
Subsequent Events
Common stock, shares outstanding										4,200,000
Class A common stock
Subsequent Events
Common stock, shares outstanding			4,237,987		4,237,987		5,363,113		8,350,065	27,200,000
Common stock, par value (In dollars per share)			$ 0.0001		$ 0.0001				$ 0.0001
Class A common stock \| Sponsor
Subsequent Events
Common stock, par value (In dollars per share)	$ 0.0001
Class B common stock
Subsequent Events
Common stock, shares outstanding			1,550,000		1,550,000				1,550,000	1,550,000	5,750,000
Common stock, par value (In dollars per share)			$ 0.0001		$ 0.0001				$ 0.0001
Class B common stock \| Sponsor
Subsequent Events
Consideration for transfer of shares	$ 0
Class B common stock \| Sponsor
Subsequent Events
Common stock, shares outstanding			312,506		312,506
Class B common stock \| Sponsor \| Sponsor
Subsequent Events
Shares transferred	262,502
Subsequent Events
Subsequent Events
Estimated federal taxes paid		$ 140,000
Minimum net tangible assets outstanding subject to non redemption				$ 5,000,001
Subsequent Events \| Sponsor \| Private placement warrants
Subsequent Events
Class of warrant or right outstanding	11,700,000
Subsequent Events \| Class A common stock \| Sponsor
Subsequent Events
Common stock, shares outstanding	4,200,000
Common stock, par value (In dollars per share)	$ 0.0001
Subsequent Events \| Class B common stock \| Sponsor
Subsequent Events
Consideration for transfer of shares	$ 0
Common stock, shares outstanding	312,506
Subsequent Events \| Class B common stock \| Sponsor \| Sponsor
Subsequent Events
Shares transferred	262,502