Note B - Securities - Available for Sale and Held to Maturity Securities with Gross Unrealized Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Less Than Twelve Months, Fair Value	$ 35,813	$ 39,242
Less Than Twelve Months, Gross Unrealized Losses	417	477
Over Twelve Months, Fair Value	55,340	175,359
Over Twelve Months, Gross Unrealized Losses	256	5,731
Total, Fair Value	91,153	214,601
Total, Gross Unrealized Losses	673	6,208
US Treasury Securities [Member]
Less Than Twelve Months, Fair Value	4,894	999
Less Than Twelve Months, Gross Unrealized Losses	44	1
Over Twelve Months, Fair Value	49,753	82,424
Over Twelve Months, Gross Unrealized Losses	231	2,442
Total, Fair Value	54,647	83,423
Total, Gross Unrealized Losses	275	2,443
US Government Agencies Debt Securities [Member]
Less Than Twelve Months, Fair Value	4,978	4,939
Less Than Twelve Months, Gross Unrealized Losses	16	61
Over Twelve Months, Fair Value	4,979	17,608
Over Twelve Months, Gross Unrealized Losses	20	569
Total, Fair Value	9,957	22,547
Total, Gross Unrealized Losses	36	630
Collateralized Mortgage Backed Securities [Member]
Less Than Twelve Months, Fair Value	10,941	24,834
Less Than Twelve Months, Gross Unrealized Losses	93	293
Over Twelve Months, Fair Value		55,649
Over Twelve Months, Gross Unrealized Losses		1,985
Total, Fair Value	10,941	80,483
Total, Gross Unrealized Losses	93	2,278
Collateralized Mortgage Obligations [Member]
Less Than Twelve Months, Fair Value	10,398
Less Than Twelve Months, Gross Unrealized Losses	203
Over Twelve Months, Fair Value
Over Twelve Months, Gross Unrealized Losses
Total, Fair Value	10,398
Total, Gross Unrealized Losses	203
US States and Political Subdivisions Debt Securities [Member]
Less Than Twelve Months, Fair Value	4,602	8,470
Less Than Twelve Months, Gross Unrealized Losses	61	122
Over Twelve Months, Fair Value	608	19,678
Over Twelve Months, Gross Unrealized Losses	5	735
Total, Fair Value	5,210	28,148
Total, Gross Unrealized Losses	$ 66	$ 857