v3.26.3
Document And Entity Information
Oct. 27, 2026
Cover [Abstract]  
Document Type 8-K
Amendment Flag false
Document Period End Date Oct. 27, 2026
Entity Registrant Name Narragansett Bancorp, Inc.
Entity Central Index Key 0002138186
Entity Emerging Growth Company true
Entity File Number 333-296731
Entity Incorporation, State or Country Code MD
Entity Tax Identification Number 42-3540071
Entity Address, Address Line One 330 Swansea Mall Drive
Entity Address, City or Town Swansea
Entity Address, State or Province MA
Entity Address, Postal Zip Code 02777
City Area Code (888)
Local Phone Number 806-2872
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Ex Transition Period false
Title of 12(b) Security N/A
No Trading Symbol Flag true
Security Exchange Name NONE