BUSINESS COMBINATIONS - Assets Acquired and Liabilities Assumed (Details)		1 Months Ended	12 Months Ended
	Oct. 01, 2025 USD ($) category	Oct. 31, 2025 USD ($)	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
BUSINESS COMBINATION
Goodwill			$ 63,311,000	$ 52,505,000	$ 52,505,000
Proceeds from Sale of Debt Securities, Available-for-sale			143,197,000	0	60,819,000
Debt Securities, Available-for-sale, Realized Gain (Loss)			$ 38,000	$ 0	$ (3,036,000)
Susquehanna
BUSINESS COMBINATION
Merger consideration	$ 44,643,000
Cash and cash equivalents	6,080,000
Available-for-sale debt securities	147,617,000
Loans, net of allowance for credit losses	386,514,000
Bank-owned life insurance	7,953,000
Bank premises and equipment,net	6,953,000
Core deposit intangible, net	10,690,000
Deferred tax asset, net	5,170,000
Other assets	14,422,000
Total identifiable assets acquired	585,399,000
Deposits	501,488,000
Short-term borrowings	45,800,000
Other liabilities	4,274,000
Total liabilities assumed	551,562,000
Total identifiable net assets	33,837,000
Goodwill	10,806,000
Total Allocation	$ 44,643,000
Proceeds from Sale of Debt Securities, Available-for-sale		$ 143,200,000
Debt Securities, Available-for-sale, Realized Gain (Loss)		$ 0
Susquehanna \| Bank And Premises Fair Value Adjustment [Member]
BUSINESS COMBINATION
Amortization period	20 years
Susquehanna \| Core Deposits
BUSINESS COMBINATION
Core deposit intangible, net	$ 10,690,000
Amortization period	4 years 2 months 12 days
Business Combination, Categories of Deposit Liabilities \| category	2
Susquehanna \| Core deposit adjustment for time deposit
BUSINESS COMBINATION
Core deposit intangible, net	$ 451,000
Amortization period	1 year 3 months
Susquehanna \| Book Value
BUSINESS COMBINATION
Cash and cash equivalents	$ 6,080,000
Available-for-sale debt securities	148,243,000
Loans, net of allowance for credit losses	396,851,000
Bank-owned life insurance	7,953,000
Bank premises and equipment,net	10,163,000
Core deposit intangible, net	0
Deferred tax asset, net	4,458,000
Other assets	13,634,000
Total identifiable assets acquired	587,382,000
Deposits	501,037,000
Short-term borrowings	45,800,000
Other liabilities	4,158,000
Total liabilities assumed	550,995,000
Total identifiable net assets	36,387,000
Goodwill	0
Total Allocation	36,387,000
Susquehanna \| Fair Value Adjustment
BUSINESS COMBINATION
Cash and cash equivalents	0
Available-for-sale debt securities	(626,000)
Loans, net of allowance for credit losses	(10,337,000)
Bank-owned life insurance	0
Bank premises and equipment,net	(3,210,000)
Core deposit intangible, net	10,690,000
Deferred tax asset, net	712,000
Other assets	788,000
Total identifiable assets acquired	(1,983,000)
Deposits	451,000
Short-term borrowings	0
Other liabilities	116,000
Total liabilities assumed	567,000
Total identifiable net assets	(2,550,000)
Goodwill	10,806,000
Total Allocation	$ 8,256,000

CITIZENS & NORTHERN CORP 10-K