XML 86 R69.htm IDEA: XBRL DOCUMENT v3.19.1

Deposits - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Banking and Thrift [Abstract]
Time deposits, in denominations of $250 thousand or more	$ 16,100	$ 14,100
Brokered deposits	$ 144	$ 550

X

- Definition

Total brokered deposits.

+ References

No definition available.

+ Details

Name:	fxnc_BrokeredDeposits
Namespace Prefix:	fxnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Time Deposits 250000 Or More

+ References

No definition available.

+ Details

Name:	fxnc_TimeDeposits250000OrMore
Namespace Prefix:	fxnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- References

No definition available.

+ Details

Name:	us-gaap_BankingAndThriftAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration