SEGMENT INFORMATION - Segment income (Details) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
INTEREST INCOME
Total interest income	$ 14,627,000	$ 13,364,000
INTEREST EXPENSE
Total interest expense	5,731,000	5,230,000
Net interest income	8,896,000	8,134,000
Provision for credit losses available-for-sale securities	20,000	451,000
Provision for credit losses loans receivable	821,000	(145,000)
Net interest income after provision for credit losses	8,055,000	7,828,000
NONINTEREST INCOME
Gain on sale of fixed assets		6,000
Earnings on deferred compensation plan assets	116,000	26,000
Net gains on sale of residential mortgage loans	136,000	87,000
Total noninterest income	2,209,000	1,866,000
NONINTEREST EXPENSE
Compensation and employee benefits	5,408,000	4,903,000
Core processing	1,596,000	1,446,000
Premises and equipment	924,000	766,000
Professional fees	426,000	232,000
Postage & office supplies	108,000	181,000
FDIC premiums	147,000	118,000
Advertising	307,000	351,000
Director fees	164,000	156,000
Intangible asset amortization	156,000	156,000
Other	847,000	569,000
Total noninterest expense	10,083,000	8,878,000
Income before provision for income taxes	181,000	816,000
PROVISION FOR INCOME TAXES	9,000	104,000
Net income	172,000	712,000
Service fees
NONINTEREST INCOME
Non-interest income	134,000	123,000
Income from financial services
NONINTEREST INCOME
Non-interest income	969,000	893,000
Fee income
NONINTEREST INCOME
Non-interest income	854,000	731,000
Operating Segments | Seneca Savings
INTEREST INCOME
Total interest income	14,627,000	13,364,000
INTEREST EXPENSE
Total interest expense	5,731,000	5,230,000
Net interest income	8,896,000	8,134,000
Provision for credit losses available-for-sale securities	20,000	451,000
Provision for credit losses loans receivable	821,000	(145,000)
Net interest income after provision for credit losses	8,055,000	7,828,000
NONINTEREST INCOME
Gain on sale of fixed assets		6,000
Earnings on deferred compensation plan assets	116,000	26,000
Net gains on sale of residential mortgage loans	136,000	87,000
Total noninterest income	1,208,000	941,000
NONINTEREST EXPENSE
Compensation and employee benefits	4,934,000	4,476,000
Core processing	1,596,000	1,446,000
Premises and equipment	900,000	742,000
Professional fees	386,000	232,000
Postage & office supplies	108,000	181,000
FDIC premiums	147,000	118,000
Advertising	299,000	344,000
Director fees	163,000	156,000
Intangible asset amortization	156,000	156,000
Other	637,000	363,000
Total noninterest expense	9,326,000	8,214,000
Income before provision for income taxes	(63,000)	555,000
PROVISION FOR INCOME TAXES	9,000	104,000
Net income	(72,000)	451,000
Operating Segments | Seneca Savings | Service fees
NONINTEREST INCOME
Non-interest income	134,000	123,000
Operating Segments | Seneca Savings | Fee income
NONINTEREST INCOME
Non-interest income	822,000	699,000
Operating Segments | Financial Quest
NONINTEREST INCOME
Total noninterest income	1,001,000	925,000
NONINTEREST EXPENSE
Compensation and employee benefits	474,000	427,000
Premises and equipment	24,000	24,000
Professional fees	40,000
Advertising	8,000	7,000
Director fees	1,000
Other	210,000	206,000
Total noninterest expense	757,000	664,000
Income before provision for income taxes	244,000	261,000
Net income	244,000	261,000
Operating Segments | Financial Quest | Income from financial services
NONINTEREST INCOME
Non-interest income	969,000	893,000
Operating Segments | Financial Quest | Fee income
NONINTEREST INCOME
Non-interest income	$ 32,000	$ 32,000