CONDENSED STATEMENT OF CHANGES IN SHAREHOLDERS’ DEFICIT (Parentheticals)	Sep. 30, 2025 shares
Class B Ordinary Shares [Member] \| Maximum [Member]
Ordinary shares subject to forfeiture (in Shares)	750,000

Number of ordinary shares subject to forfeiture if the over-allotment option is not exercised in full or in part by the underwriters.

No definition available.

Name:	gpac_OrdinarySharesSubjectToForfeiture
Namespace Prefix:	gpac_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant