BORROWED FUNDS (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Net Investment Income [Line Items]
Average weighted balance	$ 18,970,000	$ 21,496,000
Average interest rate paid during the year	2.39%	2.84%
Average interest rate at year end	2.46%	2.29%
Revolving Credit Facility [Member]
Net Investment Income [Line Items]
Highest balance at any month-end
Average weighted balance
Federal Funds Lines [Member]
Net Investment Income [Line Items]
Highest balance at any month-end	1,020,000
Average weighted balance	$ 8,000
Average interest rate paid during the year	2.51%
Short-term Debt [Member]
Net Investment Income [Line Items]
Highest balance at any month-end	$ 5,000,000	5,000,000
Average weighted balance	$ 2,466,000	$ 2,555,000
Average interest rate paid during the year	1.36%	1.36%
Average interest rate at year end		1.34%
Long-term Debt [Member]
Net Investment Income [Line Items]
Highest balance at any month-end		$ 5,000,000
Average weighted balance		$ 2,445,000
Average interest rate paid during the year		1.36%
NPB Capital Trust I [Member]
Net Investment Income [Line Items]
Highest balance at any month-end	11,341,000	$ 11,341,000
Average weighted balance	$ 11,341,000	$ 11,341,000
Average interest rate paid during the year	2.81%	3.55%
Average interest rate at year end	2.72%	2.84%
NPB Capital Trust 2 [Member]
Net Investment Income [Line Items]
Highest balance at any month-end	$ 5,155,000	$ 5,155,000
Average weighted balance	$ 5,155,000	$ 5,155,000
Average interest rate paid during the year	1.97%	2.70%
Average interest rate at year end	1.89%	2.01%