PARENT COMPANY ONLY FINANCIAL INFORMATION - Parent Only Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Cash flows from operating activities:
Net income	$ 172	$ 712
Adjustments to reconcile net income to net cash provided by operating activities:
Net change in other assets	(416)	(165)
Net change in other liabilities	4,033	513
Stock based compensation expense	61	74
Net cash flow provided by operating activities	4,767	1,715
Cash flows from investing activities:
Net cash flow used in investing activities	(32,018)	(21,061)
Cash flows from financing activities:
Net proceeds from stock offering and conversion	8,565
Purchase of ESOP shares	(836)
Issuance and exchange of common stock	9
Repurchase of shares into treasury stock		70
Net cash flow provided by financing activities	25,791	22,214
Net change in cash and cash equivalents	(1,460)	2,868
CASH AND CASH EQUIVALENTS - beginning of the period	6,788	3,920
CASH AND CASH EQUIVALENTS - end of the period	5,328	6,788
Seneca Financial Corp (Parent Company)
Cash flows from operating activities:
Net income	172	712
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed income of Bank	(536)	(869)
Net change in other assets	(87)	(43)
Net change in other liabilities	372
Stock based compensation expense	61	75
Net cash flow provided by operating activities	(18)	(125)
Cash flows from investing activities:
Payments received on ESOP loan	82	18
Net cash flow used in investing activities	82	18
Cash flows from financing activities:
Net proceeds from stock offering and conversion	8,565
Purchase of ESOP shares	(836)
Distribution to bank subsidiary	(4,613)
Issuance and exchange of common stock	9
Repurchase of shares into treasury stock		(70)
Net cash flow provided by financing activities	3,125	(70)
Net change in cash and cash equivalents	3,189	(177)
CASH AND CASH EQUIVALENTS - beginning of the period	79	256
CASH AND CASH EQUIVALENTS - end of the period	$ 3,268	$ 79