v3.26.1
Cover Page - USD ($)
$ in Millions
12 Months Ended
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.