Cover Page - USD ($) $ in Millions	12 Months Ended
Cover Page - USD ($) $ in Millions	Dec. 31, 2025	Mar. 06, 2026	Jun. 30, 2025
Document Information [Line Items]
Document Type	10-K/A
Amendment Flag	true
Amendment Description	This Amendment to the Annual Report on Form 10-K of Princeton Bancorp, Inc. for the fiscal year ended December 31, 2025, originally filed on March 13, 2026 (the “Original Filing”), amends Item 15 of Part IV of the Original Filing to include exhibit 97.1, which was inadvertently omitted. Except as described above, no other changes have been made to the Original Filing, and this Amendment does not modify, amend or update in any way any of the financial or other information contained in the Original Filing. This Amendment does not reflect events that may have occurred subsequent to the filing date of the Original Filing.
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2025
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Entity Registrant Name	PRINCETON BANCORP, INC.
Entity Central Index Key	0001913971
Current Fiscal Year End Date	--12-31
Entity Incorporation, State or Country Code	PA
Entity File Number	001-41589
Entity Tax Identification Number	88-4268702
Entity Address, Address Line One	183 Bayard Lane
Entity Address, City or Town	Princeton
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	08540
City Area Code	609
Local Phone Number	921-1700
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Title of 12(b) Security	Common stock, no par value
Trading Symbol	BPRN
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		6,788,551
ICFR Auditor Attestation Flag	true
Entity Public Float			$ 164.0
Document Financial Statement Error Correction [Flag]	false
Documents Incorporated by Reference [Text Block]	DOCUMENTS INCORPORATED BY REFERENCE The registrant intends to file a definitive Proxy Statement for the Annual Meeting of Shareholders scheduled to be held April 21, 2026. The information required by Part III of this Form 10-K is incorporated by reference to such Proxy Statement.

Princeton Bancorp, Inc. 10-K/A