Nature of Operations (Details) $ in Millions	Jan. 13, 2021 USD ($) shares	Jul. 31, 2020
Organization and Nature of Operations
Issuance of shares (in shares) | shares	1,477,575
Exchange ratio of shares	0.9980
Gross offering proceeds from sale of stocks | $	$ 14.8
Net proceeds from sale | $	$ 13.2
Seneca-Cayuga Bancorp, Inc. (the "Holding Company")
Organization and Nature of Operations
ESOP shares committed to be released (in shares) | shares	109,450
Seneca Falls Savings Bank, MHC (the "Mutual Holding Company") | Seneca-Cayuga Bancorp, Inc. (the "Holding Company")
Organization and Nature of Operations
Percentage of holding		60.10%