Note 4 - Securities - Securities in a Continuous Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Temporarily impaired securities, less than 12 months, fair value	$ 1,386	$ 6,221
Temporarily impaired securities, less than 12 months unrealized loss	18	146
Temporarily impaired securities, 12 months or more fair value	569,840	577,726
Temporarily impaired securities, 12 months or more unrealized loss	69,002	78,476
US Government Agencies Debt Securities [Member]
Temporarily impaired securities, less than 12 months, fair value	0	0
Temporarily impaired securities, less than 12 months unrealized loss	0	0
Temporarily impaired securities, 12 months or more fair value	306,927	311,124
Temporarily impaired securities, 12 months or more unrealized loss	33,268	40,012
US States and Political Subdivisions Debt Securities [Member]
Temporarily impaired securities, less than 12 months, fair value	0	885
Temporarily impaired securities, less than 12 months unrealized loss	0	118
Temporarily impaired securities, 12 months or more fair value	147,612	144,849
Temporarily impaired securities, 12 months or more unrealized loss	30,332	32,254
Commercial Mortgage-Backed Securities [Member]
Temporarily impaired securities, less than 12 months, fair value	1,386	5,336
Temporarily impaired securities, less than 12 months unrealized loss	18	28
Temporarily impaired securities, 12 months or more fair value	109,515	115,011
Temporarily impaired securities, 12 months or more unrealized loss	4,680	5,445
Corporate Debt Securities [Member]
Temporarily impaired securities, less than 12 months, fair value	0	0
Temporarily impaired securities, less than 12 months unrealized loss	0	0
Temporarily impaired securities, 12 months or more fair value	5,786	5,743
Temporarily impaired securities, 12 months or more unrealized loss	$ 722	764
US Treasury Securities [Member]
Temporarily impaired securities, less than 12 months, fair value		0
Temporarily impaired securities, less than 12 months unrealized loss		0
Temporarily impaired securities, 12 months or more fair value		999
Temporarily impaired securities, 12 months or more unrealized loss		$ 1

NATIONAL BANKSHARES INC 10-Q