Note P - Fair Value Measurements and Disclosures - Assets Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	$ 339,477	$ 350,168
Fair Value, Inputs, Level 1 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	0	0
Fair Value, Inputs, Level 2 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	339,477	350,168
Fair Value, Inputs, Level 3 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	0	0
Fair Value, Recurring [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	339,477	350,168
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	339,477	350,168
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	0	0
US Treasury Securities [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	115,458	108,368
US Treasury Securities [Member] | Fair Value, Recurring [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	115,458	108,368
US Treasury Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	0	0
US Treasury Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	115,458	108,368
US Treasury Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	0	0
Collateralized Mortgage-Backed Securities [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	47,785	56,439
Collateralized Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	47,785	56,439
Collateralized Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	0	0
Collateralized Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	47,785	56,439
Collateralized Mortgage-Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	0	0
Collateralized Mortgage Obligations [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	95,006	107,377
Collateralized Mortgage Obligations [Member] | Fair Value, Recurring [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	95,006	107,377
Collateralized Mortgage Obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	0	0
Collateralized Mortgage Obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	95,006	107,377
Collateralized Mortgage Obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	0	0
US States and Political Subdivisions Debt Securities [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	81,228	77,984
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	81,228	77,984
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	0	0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	81,228	77,984
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Available for sale securities, amortized cost of $379,195-2023; $397,926-2022	$ 0	$ 0