BORROWED FUNDS (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Balance for the year		$ 27,126	$ 24,054
Average weighted balance		$ 26,106	$ 26,088
Average interest rate paid during the year		3.53%	2.85%
Average interest rate at year end		3.67%	3.02%
Revolving Advances [Member]
Balance for the year	[1]
Highest balance at any month-end	[1]	12,000
Average weighted balance	[1]	$ 2,367
Average interest rate paid during the year	[1]	2.19%	0.00%
Average interest rate at year end	[1]	0.00%	0.00%
Federal Funds Lines [Member]
Balance for the year	[2]	$ 3,630
Highest balance at any month-end	[2]	3,630	1,227
Average weighted balance	[2]	$ 109	$ 253
Average interest rate paid during the year	[2]	2.80%	2.10%
Average interest rate at year end	[2]	3.28%	0.00%
Loans Short-Term[Member]
Balance for the year	[3]	$ 2,000	$ 558
Highest balance at any month-end	[3]	2,000	6,200
Average weighted balance	[3]	$ 1,159	$ 1,981
Average interest rate paid during the year	[3]	1.43%	1.82%
Average interest rate at year end	[3]	0.99%	4.07%
Loans Long-Term [Member]
Balance for the year	[4]	$ 5,000	$ 7,000
Highest balance at any month-end	[4]	7,000	8,717
Average weighted balance	[4]	$ 5,975	$ 7,358
Average interest rate paid during the year	[4]	1.28%	1.50%
Average interest rate at year end	[4]	1.34%	1.34%
NPB Capital Trust I [Member]
Balance for the year	[5]	$ 11,341	$ 11,341
Highest balance at any month-end	[5]	11,341	11,341
Average weighted balance	[5]	$ 11,341	$ 11,341
Average interest rate paid during the year	[5]	4.96%	3.85%
Average interest rate at year end	[5]	5.04%	3.96%
NPB Capital Trust 2 [Member]
Balance for the year	[5]	$ 5,155	$ 5,155
Highest balance at any month-end	[5]	5,155	5,155
Average weighted balance	[5]	$ 5,155	$ 5,155
Average interest rate paid during the year	[5]	4.08%	3.01%
Average interest rate at year end	[5]	4.21%	3.13%

[1] The Bank has the ability to borrow up to an additional $115.6 million from the FHLB under a line of credit which is secured by a blanket lien on residential real estate loans. The Bank had no overnight borrowings subject to daily rate changes from the Federal Home Loan Bank at December 31, 2018 or 2017. We have used our line of credit with FHLB to issue letters of credit totaling $17.0 million to the Treasury Board of Virginia for collateral on public funds deposited in the Bank. No draws on the letters of credit have been issued. The letters of credit are considered draws on our Federal Home Loan Bank line of credit.

[2] Federal funds lines consist of $20.0 million and $10.0 million in unsecured and secured federal funds line of credit facilities with correspondent banks as of December 31, 2018 and 2017, respectively, exclusive of any outstanding balance. At December 31, 2018 and 2017 $5 million of the available lines is secured by certain investment securities.

[3] Short term FHLB advances at December 31, 2018 consisted of $2.0 million at a fixed rate of 0.99% due in 2019. At December 31, 2017 short-term advances consisted of two principal reducing borrowings totaling $558 thousand at an average fixed rate of 4.07% due in 2018.

[4] Long-term FHLB advances at December 31, 2018 consisted of $5.0 million at a fixed rate of 1.38% due in 2021. At December 31, 2017 long term FHLB advances consisted of $2.0 million at a fixed rate of 0.99% due in 2019 and $5.0 million at a fixed rate of 1.38% due in 2021

[5] TPS I - On July 7, 2004, the Company completed the issuance of $11.3 million in floating rate trust preferred securities offered by its wholly owned subsidiary, NPB Capital Trust I (TPS I). The rate is determined quarterly and floats based on the 3 month LIBOR plus 260 bps. TPS 2 - On September 27, 2006, the Company completed the issuance of $5.2 million in floating rate trust preferred securities offered by its wholly owned subsidiary, NPB Capital Trust 2 (TPS 2). The rate is determined quarterly and floats based on the 3 month LIBOR plus 177 bps.