BORROWINGS - Contractual maturities and weighted average rates of advances from FHLBNY (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Contractual maturities
2025	$ 2,000
2026	13,814
2027	8,753
2028	13,000
2029	2,000
2030	1,000
Total	$ 40,567	$ 41,253
Weighted average rates
2025	4.54%
2026	2.75%
2027	3.51%
2028	4.42%
2029	4.61%
2030	4.33%
Total	3.67%

Weighted average interest rate of advance from Federal Home Loan Bank (FHLBank).

No definition available.

Name:	snnf_FederalHomeLoanBankAdvanceMaturityAverageInterestRate
Namespace Prefix:	snnf_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted average interest rate of advance from Federal Home Loan Bank (FHLBank) due in remainder of fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

No definition available.